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HRV apps compared: Kubios, Elite HRV, HRV4Training

Kubios HRV, Elite HRV, HRV4Training and Welltory all take a short morning reading and turn the gaps between your heartbeats into an HRV number built on RMSSD. They differ in the sensor they need, the score they put on top, how much of that score they publish, and what you can take away. Elite HRV and Welltory export the raw beats, HRV4Training and Welltory work with the phone camera, and Kubios with the phone lying on your chest.

Intermediate By HRV Expert Editorial Team Edited by Sabir Shaykhlislamov Updated 19 min read

On this page 11 sections

Key takeaways

  • All four apps work from the intervals between heartbeats in a short resting reading and build their main number on RMSSD. None of them publishes every step from the beats to the score.
  • All four take a Bluetooth chest strap; Kubios and Elite HRV name the Polar H10 as their first choice. Without a strap, HRV4Training and Welltory read your pulse through the phone camera, and Kubios through the phone lying on your chest.
  • Elite HRV has the most studies against an ECG by independent researchers, all with a chest strap. HRV4Training's camera was tested in 29 adults with its developer among the authors and in 5 adults independently, Welltory's in 26 cyclists, and Kubios's phone-on-chest method only in the maker's own report.
  • Elite HRV and Welltory export the raw RR intervals. Kubios readings open in its desktop software, free for non-commercial use in the Lite version, and HRV4Training does not document its export format.
  • On 24 October 2026 in the US, the Kubios and Elite HRV apps were free, HRV4Training cost $9.99 once on iPhone and $11.99 on Android, and Welltory Premium cost $99.99 to $119.99 a year after a 3-day trial.

The best HRV app depends on the sensor you have and what you want from it. With a chest strap, Elite HRV and Kubios HRV are free and take a careful morning reading; with only a phone, HRV4Training and Welltory read your pulse through the camera and Kubios through the phone lying on your chest; to analyse recordings in depth, Kubios HRV Scientific is the desktop software researchers often use as their reference (Perrotta and colleagues, 2017). All four turn the same raw material, the intervals between your heartbeats, into a number built on RMSSD RMSSD Root mean square of successive differences: an HRV metric built from how much each heartbeat interval differs from the next, in milliseconds. It mainly reflects vagal activity. More about RMSSD , and none of them publishes every step on the way.

We checked the makers’ help pages, product pages, store listings and the published studies on 24 October 2026. Prices are from the US App Store, Google Play and the makers’ own sites, in US dollars; they change and differ by country. This page has no affiliate links.

The four apps side by side

Four HRV apps side by side

From the makers’ pages and the studies, 24 October 2026

Kubios HRV iPhone, Android and Windows and macOS Elite HRV iPhone, Android and web HRV4Training iPhone, Android and web Welltory iPhone, Android and web
How it measures
  • Chest strap
  • Phone camera
  • Phone on chest
  • Watch or ring

The phone lying on your chest, or a strap such as the Polar H10. No camera, and no Apple Watch.
  • Chest strap
  • Phone camera
  • Phone on chest
  • Watch or ring

A chest strap or other Bluetooth monitor that sends RR intervals. Camera readings only in a research test.
  • Chest strap
  • Phone camera
  • Phone on chest
  • Watch or ring

Phone camera, a Polar strap or Scosche armband, Apple Watch readings through Apple Health, Oura’s night data.
  • Chest strap
  • Phone camera
  • Phone on chest
  • Watch or ring

Phone camera, a strap that sends RR intervals, an Apple Watch or a Samsung watch. Not Garmin watches or Oura.
Number it shows
Readiness, from a PNS index set against your last 3 months, with RMSSD, an SNS index and a “physiological age”. HRV Score from 0 to 100, a stretched ln(RMSSD), and a readiness gauge against your baseline. A log transform of rMSSD, or rMSSD in ms, against your 7-day baseline and 2-month normal range, with daily advice. An HRV Score from lnRMSSD as a percentage, plus Stress, Energy, Focus and Health, and RMSSD, SDNN and more.
Compared with an ECG
Export
Through Kubios software Readings open in Kubios HRV Scientific, whose free Lite version saves results as CSV or PDF. RR file Every reading as a text file of RR intervals, through an emailed link. RR file not documented By email or Dropbox; the file format is not documented. Pro exports CSV. RR file RR intervals, or every value of a chart, as CSV from the web app.
Price
App free. Scientific $735 a year, $425 academic; Lite free for non-commercial use. App free; integrations $4.99 once. Personal Pro dashboard $8 a month or $76.80 a year. $9.99 once on iPhone, $11.99 on Android. Pro for teams $3 per athlete a month. Free with one reading a day and 30 days of history. Premium $99.99 to $119.99 a year, or $299.99 once.

  • Kubios HRV iPhone, Android and Windows and macOS

    How it measures
    • Chest strap
    • Phone camera
    • Phone on chest
    • Watch or ring

    The phone lying on your chest, or a strap such as the Polar H10. No camera, and no Apple Watch.

    Number it shows
    Readiness, from a PNS index set against your last 3 months, with RMSSD, an SNS index and a “physiological age”.
    Compared with an ECG
    Export
    Through Kubios software Readings open in Kubios HRV Scientific, whose free Lite version saves results as CSV or PDF.
    Price
    App free. Scientific $735 a year, $425 academic; Lite free for non-commercial use.

  • Elite HRV iPhone, Android and web

    How it measures
    • Chest strap
    • Phone camera
    • Phone on chest
    • Watch or ring

    A chest strap or other Bluetooth monitor that sends RR intervals. Camera readings only in a research test.

    Number it shows
    HRV Score from 0 to 100, a stretched ln(RMSSD), and a readiness gauge against your baseline.
    Compared with an ECG
    Export
    RR file Every reading as a text file of RR intervals, through an emailed link.
    Price
    App free; integrations $4.99 once. Personal Pro dashboard $8 a month or $76.80 a year.

  • HRV4Training iPhone, Android and web

    How it measures
    • Chest strap
    • Phone camera
    • Phone on chest
    • Watch or ring

    Phone camera, a Polar strap or Scosche armband, Apple Watch readings through Apple Health, Oura’s night data.

    Number it shows
    A log transform of rMSSD, or rMSSD in ms, against your 7-day baseline and 2-month normal range, with daily advice.
    Compared with an ECG
    Export
    RR file not documented By email or Dropbox; the file format is not documented. Pro exports CSV.
    Price
    $9.99 once on iPhone, $11.99 on Android. Pro for teams $3 per athlete a month.

  • Welltory iPhone, Android and web

    How it measures
    • Chest strap
    • Phone camera
    • Phone on chest
    • Watch or ring

    Phone camera, a strap that sends RR intervals, an Apple Watch or a Samsung watch. Not Garmin watches or Oura.

    Number it shows
    An HRV Score from lnRMSSD as a percentage, plus Stress, Energy, Focus and Health, and RMSSD, SDNN and more.
    Compared with an ECG
    Export
    RR file RR intervals, or every value of a chart, as CSV from the web app.
    Price
    Free with one reading a day and 30 days of history. Premium $99.99 to $119.99 a year, or $299.99 once.
How each app measures, the number it shows, the studies that compared it with an ECG recorded at the same time, what it exports and what it costs, as the makers documented them on 24 October 2026. Prices are in US dollars, from the US App Store, Google Play and the makers’ own pages; they change and differ by country. A filled dot is a study by researchers independent of the maker, a hollow dot a paper with the app’s developer among its authors, and a dashed dot the maker’s own report, not peer reviewed.

The four have more in common than their scores suggest. Each takes a short reading at rest, usually one to five minutes, ideally just after waking. Each works from the RR intervals RR interval The time from one heartbeat to the next, measured in milliseconds between the R peaks of an ECG. HRV is calculated from a series of these intervals. More about RR interval , the gaps between beats, and each computes RMSSD, the root mean square of successive differences between them, the standard measure of short-term, beat-to-beat HRV (Task Force, 1996). And each makes its main number personal by setting today’s reading against your own recent readings.

They also differ in upkeep. On the US App Store on 24 October 2026, Welltory’s iPhone app was last updated on 15 October 2026, HRV4Training’s on 23 September 2026 and Kubios’s on 22 June 2026. Elite HRV’s was last updated on 2 November 2023; its Android app on Google Play, on 23 October 2025.

Which HRV app should you use?

  • To analyse recordings in depth: Kubios HRV Scientific, on Windows or macOS. It opens RR files from straps and watches and ECG ECG A recording of the heart's electrical activity, taken with electrodes on the skin. ECG-based RR intervals are the reference standard for measuring HRV. More about ECG recordings, corrects artifacts Artifact An error in a heartbeat recording, such as a missed, extra or mistimed beat, often caused by movement or poor sensor contact. Artifacts can badly distort HRV numbers. More about Artifact with an algorithm whose accuracy is published, and exports CSV, PDF and MAT files. The full licence cost $735 a year, or $425 for academic use, before tax. The free Lite version, for non-commercial use, works out the standard measures but corrects beats only with a fixed threshold.
  • A daily morning reading with a chest strap: Elite HRV or the Kubios HRV app. Both are free. Elite HRV has the most independent studies against an ECG and exports every reading’s beats; Kubios builds its readiness on a broader index and keeps your data on servers in the EU or EEA.
  • No extra hardware: HRV4Training, through the phone camera, for $9.99 once on iPhone; the Kubios HRV app, free, with the phone lying on your chest; or Welltory, through the camera, whose free version allows one reading a day after a 3-day trial.
  • An Apple Watch you already wear: HRV4Training and Welltory can read its readings through Apple Health. Kubios and Elite HRV cannot.
  • Coaches and teams: Elite HRV’s team dashboard ($30 to $100 a month by team size), HRV4Training Pro ($3 per athlete a month) or Kubios HRV Team Readiness ($360 to $1,260 a year for 10 to 50 members). Each lets athletes take their morning reading in the app and the coach see everyone’s trend.

How each app measures your heartbeat

With a chest strap

A chest strap times each beat from the heart’s electrical signal and sends the RR intervals to the app over Bluetooth. All four apps accept one; the chest-strap guide explains how the strap works.

  1. ECG chest strap Bought once. Times each R peak from the heart’s electrical signal.
  2. RR intervals over Bluetooth Sent in the standard heart rate message. RR is optional there, so check that the strap sends it.
  3. Free app or web tool Works out RMSSD from the intervals, with no subscription.
  4. Your own baseline Same time and position each morning; each reading is compared with your usual range.
The no-subscription setup. The strap times each heartbeat from the heart’s electrical signal and sends the gaps between beats over Bluetooth; a free app or web tool works out RMSSD; your own baseline gives each reading its meaning.
  • Kubios: “For the highest level of accuracy, an ECG-based chest strap sensor like the Polar H10 is the recommended choice.” The app takes any Bluetooth Low Energy sensor that sends RR intervals, not ANT+. Kubios warns that optical sensors’ “typical ±5 ms beat detection inaccuracy can lead to errors up to ±10% in HRV parameters” (Kubios, HRV app).
  • Elite HRV recommends the Polar H10. It accepts Bluetooth Low Energy and, on some Android devices, ANT+, and the monitor must send its beats to the app live: the app cannot read beats stored on another device (Elite HRV, compatibility).
  • HRV4Training lists the Polar H7, H9 and H10 straps and the Scosche Rhythm24 armband (HRV4Training, QuickStart).
  • Welltory works with a monitor that records “raw RR-intervals” and sends them over Bluetooth 4.0; it does not support ANT+ (Welltory, device compatibility).

With the phone camera

HRV4Training and Welltory can measure with no sensor at all. You cover the rear camera and the flash with a fingertip, the flash lights the skin, and the app reads the pulse from the tiny changes in brightness with each heartbeat.

Phone camera brightness 1 2 3 4 Ring and finger clip 5 6
  1. Flash: an LED lights the fingertip from below
  2. Light scatters through the skin and its small blood vessels, and some comes back out
  3. Camera lens: each frame’s brightness becomes one sample
  4. Each heartbeat dims the light a little: one pulse wave per beat
  5. Ring: light and sensor side by side at the base of the finger (reflection)
  6. Finger clip: light shines through the fingertip to a sensor on the other side (transmission)
Three ways to read the pulse at the finger. A phone camera (1 to 4) and a ring (5) catch light that scatters back out of the skin. A finger-clip pulse oximeter (6) catches light that passes right through the fingertip. A simplified drawing, not to scale.

HRV4Training says 60 seconds is enough for “a reliable measurement of rMSSD”, and its camera mode needs an iPhone 5 or later (HRV4Training, FAQ). Welltory asks you to cover “both the camera and the flashlight” without pressing hard; on some phones, such as the Google Pixel 6 and 7, the flash sits too far from the camera to work, and on the iPhone 17 Air, Pro and Pro Max you can use the front camera (Welltory, camera measurements).

Elite HRV has no camera mode for everyday use. Its help centre says “you will not be able to take your HRV with only a mobile device”; finger-on-camera readings were open only to part of its users, as a research test (Elite HRV, using the app without a monitor). Fingertip HRV explains why the camera’s frame rate and your finger pressure matter, and can a phone camera measure HRV? sums up the evidence.

With the phone on your chest

The Kubios HRV app has a third way. You lie still with the phone flat on your chest, and its accelerometer picks up “subtle chest wall vibrations caused by each heartbeat”, a method called seismocardiography. Kubios says it works on most iPhones and Android phones, but that some older or low-end Android phones have too much sensor noise, and the app then tells you the signal is inadequate (Kubios, HRV app; Kubios, SCG accuracy). Any movement or talking spoils it, so this is a lying-down reading only.

From a watch or ring

  • HRV4Training can read HRV and RR intervals from Apple Health when you take a reading with the Apple Watch’s Breathe app, and it can read Oura’s night data “so that you do not need to take the morning measurement” (HRV4Training, FAQ).
  • Welltory works with an Apple Watch, through Apple Health, and with Samsung watches. Garmin and Oura do not let it have their HRV data, and Fitbit gives it only daily summaries, “not RR intervals with timestamps” (Welltory, trackers and smartwatches).
  • Kubios and Elite HRV do not support the Apple Watch.

None of the four is built for overnight readings. Elite HRV “is not designed for readings longer than 30 minutes” (Elite HRV, overnight readings), HRV4Training takes one measurement a day, and Kubios records long sessions only in its research mode, which needs a Scientific licence to store the data. For nightly HRV, a watch, ring or band does that work; overnight vs morning HRV explains why the two kinds of number should not be mixed.

What number each app shows

Every app starts from RMSSD and then reshapes it. The figure follows each one from the beats to the number on screen, and marks which steps the maker spells out.

From beats to the number on screen

What each maker publishes, 24 October 2026

The steps each app takes from your heartbeats to the number it shows, as its maker described them on 24 October 2026. A solid box is a step whose method the maker, or a paper about the app, spells out; a dashed box is a step the maker names without saying how it is done. Every app keeps at least two steps to itself, so two apps given the same beats can show different numbers.

Kubios: readiness from the PNS index

Kubios builds its main number from three values, not RMSSD alone: the mean RR Mean RR The average time between heartbeats in a recording, in milliseconds. Heart rate is the same number upside down: 60,000 divided by the mean RR. More about Mean RR interval, RMSSD and SD1 SD1 and SD2 Two measures of the spread of dots in a Poincaré plot, in milliseconds. SD1 is the width and tracks short-term variability, like RMSSD; SD2 is the length and tracks overall variability. More about SD1 and SD2 , a measure from the Poincaré plot Poincaré plot A scatter plot of each heartbeat interval against the one after it, in milliseconds on both axes. The shape of the cloud of dots shows short-term and overall variability at a glance. More about Poincaré plot . “Each parameter’s value is first standardized against normal population values”, then “a proprietary weighting is applied” to give the parasympathetic nervous system Parasympathetic nervous system The "rest and digest" branch of the autonomic nervous system. It slows the heart, mainly through the vagus nerve, and drives most of the beat-to-beat variation in HRV. More about Parasympathetic nervous system (PNS) index (Kubios, PNS and SNS indexes). Zero means average for the population; at rest the index usually stays within 2 standard deviations either side. A matching SNS index uses mean heart rate, SD2 and Baevsky’s stress index Baevsky stress index A number built from the histogram of heartbeat intervals, with no unit. It rises as the rhythm gets steadier and less variable, which Baevsky read as strain on the body's regulation. More about Baevsky stress index , explained in what is the Baevsky stress index?.

The readiness score Readiness score A single number, often out of 100, that a device builds from your HRV, resting heart rate, sleep and other inputs to suggest how ready you are for the day. The weighting is not published. More about Readiness score compares today’s PNS index with “your customary resting HRV values from the past 3 months”, and sorts it into four bands, which Kubios describes by how often you land in each: very low (only 2 to 3% of your results), low (about 14%), normal (around 68%) and high (about 16%). Kubios says 1 to 2 weeks of readings are needed before the score means much (Kubios, readiness score). The app also gives a “physiological age”, estimated from RMSSD divided by the square root of the mean RR interval and set against population data for ages 18 to 86 (Kubios, physiological age).

Elite HRV: a 0 to 100 score from ln(RMSSD)

Elite HRV cleans “obvious artifacts”, computes RMSSD, takes its natural log and stretches that onto a 0 to 100 scale. “The ln(RMSSD) lnRMSSD The natural logarithm of RMSSD, with no unit. Taking the log evens out the spread of RMSSD values, which makes day-to-day changes easier to compare and analyse. More about lnRMSSD value typically ranges from 0 to 6.5”, and the scale was set from over 6,000,000 readings; the exact stretch is not given (Elite HRV, HRV score). The average Elite HRV user scores about 59 (Elite HRV, good HRV score).

What is in a readiness score?

From the makers' own documentation

Elite HRV HRV Score 0–100. "The ln(RMSSD) value typically ranges from 0 to 6.5" and is stretched onto the scale.
  • HRV RMSSD from a reading with a chest strap or another Bluetooth sensor, with "a natural log (ln) applied".
  • Resting heart rate Not named by the maker.
  • Breathing rate Not named by the maker.
  • Sleep Not named by the maker.
  • Temperature Not named by the maker.
  • Activity or load Not named by the maker.

Elite HRV's HRV Score is HRV only: a rescaled HRV number, not a mix. The score is a rescaled ln(RMSSD), set so that "everyone fits in a 0 to 100 range" using over 6 million readings. The exact mapping is not given.

Source: How do you calculate the HRV score? (Elite HRV)

Welltory HRV Score A percentage: "A score near 100% reflects an ideal state."
  • HRV "Calculated from lnRMSSD."
  • Resting heart rate Not named by the maker.
  • Breathing rate Not named by the maker.
  • Sleep Not named by the maker.
  • Temperature Not named by the maker.
  • Activity or load Not named by the maker.

Welltory's HRV Score is HRV only: a rescaled HRV number, not a mix. Welltory names lnRMSSD as the input and publishes no formula or thresholds.

Source: Heartbeat Report or Nervous System Snapshot: how we interpret heart rate variability metrics

What each maker says goes into its score, checked against its own documentation between 14 and 22 October 2026. A tick means the maker names that input; a dash means it does not. No maker publishes the formula or the weights, so two devices can read the same night and give different scores.

The readiness gauge compares each morning reading with your baseline Baseline Your own usual HRV level and range, built from weeks of readings taken the same way. Comparing a reading with your baseline says more than comparing it with other people. More about Baseline . The app gives a first estimate after 2 days, keeps building the baseline for about 2 weeks, then updates it “on a rolling 10-day basis”, using the standard deviation and coefficient of variation of your readings (Elite HRV, baseline). If your readings are usually steady, a small change moves the gauge a lot; if they swing widely, a larger change may not move it (Elite HRV, Morning Readiness). What is an HRV score out of 100? explains why such a score cannot be compared across apps.

HRV4Training: a log of rMSSD against your normal range

HRV4Training’s home-screen number “is computed as a logarithmic transformation of rMSSD”, and a setting switches the display to rMSSD in milliseconds (HRV4Training, FAQ). The last week of readings sets your baseline, which needs at least 4 days, and the past 2 months set your “normal range” (HRV4Training, QuickStart). Daily advice combines where your HRV sits against your normal values with how you say you feel and your recent trends. The app also stores SDNN SDNN The standard deviation of all NN intervals in a recording, in milliseconds. It measures overall variability, and its value depends strongly on how long the recording lasts. More about SDNN , pNN50 pNN50 The percentage of neighbouring NN intervals that differ by more than 50 milliseconds. It tracks fast, vagally driven changes, like RMSSD, but as a share rather than a size. More about pNN50 and frequency-domain powers for each reading (App Store, HRV4Training).

Welltory: an HRV Score, plus Stress, Energy, Focus and Health

Welltory’s HRV Score is “calculated from lnRMSSD”, and “a score near 100% reflects an ideal state”. Next to it come Stress, Energy, Focus and Health, which Welltory calls personalised, and a report of standard measures (SDNN, pNN50, RMSSD, AMo50 and others) that “are based on general population norms” (Welltory, Heartbeat Report). Welltory publishes no formula for the score or for the four other values. Its frequency analysis appears only when a reading holds at least 300 RR intervals.

How accurate are HRV apps?

An app’s accuracy comes from two things: how well the sensor times each beat, and whether the app’s software turns those beats into the right number. Studies test one or the other, so it helps to keep them apart. The device validation tracker lists the device studies we have checked.

Elite HRV

Three studies set Elite HRV’s calculations beside other software, using the same beats or a second strap worn at the same time. Over 14 mornings of waking readings, the same beats worked out in Elite HRV and in Kubios HRV gave ln(RMSSD) values that correlated at r = 0.92, with a mean bias of −2.7% (Perrotta and colleagues, 2017). Against a Polar V800 watch, each paired with its own Polar H10 in 22 people, agreement was excellent, with intraclass correlations of 0.938 to 0.998 (Himariotis and colleagues, 2022); a third study, in 20 male students, found the same against the V800 (Chhetri and colleagues, 2022).

Three more set Elite HRV with a chest strap against an ECG recorded at the same time. In 26 professional cyclists, lying and sitting, there was no difference from the ECG (Moya-Ramon and colleagues, 2022). In 20 young adults with a Polar H10, median differences were 1.3 ms or less and agreement was very large or better for the time-domain measures, but the limits of agreement for the frequency measures were “excessively wide” (Vondrasek and colleagues, 2023). In the smallest, 5 adults over 148 seated trials, RMSSD from Elite HRV with a Polar H10 was 7.66% from the ECG on average (Stone and colleagues, 2021).

HRV4Training

In 29 healthy people recorded for 5 minutes, RMSSD from a smartphone camera and from a Polar H7 strap both differed only trivially from an ECG (Plews and colleagues, 2017). Marco Altini, who develops HRV4Training, is one of the authors; a later independent study names this as the earlier validation of HRV4Training (Stone and colleagues, 2021). In that later study, HRV4Training with a Polar H10 was the closest to the ECG of all the products tested, 4.10% off on average, and with the iPhone camera 9.43% off.

Welltory

The one independent study is the cyclist study above. Welltory, measuring by photoplethysmography PPG An optical method that shines light into the skin and detects the pulse of blood with each heartbeat. Most watches, rings and phone-camera apps use it to estimate HRV. More about PPG , showed no difference from the ECG lying or sitting, with correlations of 0.77 to 0.94 across both apps, and 1-minute readings matched 5-minute ones (Moya-Ramon and colleagues, 2022). Welltory also cites a study of its own, which it says showed camera readings “equal to measurements taken with Polar chest straps” (Welltory, why trust PPG), and four authors working for Welltory published an algorithm that finds the pulse peaks in smartphone camera signals and sets aside corrupted stretches, tested on readings taken with the app (Neshitov and colleagues, 2021); Welltory does not say whether the app runs it. Welltory itself says camera readings are “unreliable for people with arrhythmias” (Welltory, camera measurements).

Kubios

The phone-on-chest method has been tested only in Kubios’s own white paper, on a study Kubios ran with the University of Eastern Finland, not peer reviewed. In 57 healthy adults lying still, RMSSD from the phone was 2.0 ms from a laboratory ECG on average, against 2.6 ms for an optical armband (Kubios, SCG accuracy). We found no independent study of the app.

Kubios’s analysis software has a longer record. Its developers described it in a peer-reviewed paper (Tarvainen and colleagues, 2014), and published the automatic beat correction Beat correction Finding the beat intervals that are wrong (missed, extra or ectopic beats) and deleting or replacing them before HRV is calculated. The rule of thumb is to correct under 5% of beats. More about Beat correction of Kubios HRV Scientific: it caught 100% of simulated missed and extra beats and 96.96% of real ectopic beats Ectopic beat A heartbeat that starts outside the heart's normal pacemaker and usually comes early. Ectopic beats are common, but they distort HRV unless removed or corrected. More about Ectopic beat , and after correction left HRV values within 2% for missed, extra and most misaligned beats (Lipponen and Tarvainen, 2019). The Kubios app’s page names “noise detection and beat correction” but does not say whether it runs the same algorithm.

What the studies do not tell you

Nearly all of this evidence comes from small groups of healthy, mostly young people at rest. No study compared all four apps, and a good result for one camera app does not carry over to another, or to another phone. These are wellness apps, not medical devices: HRV4Training’s terms say its service “is not intended to diagnose, treat, cure, or prevent any disease”, and Welltory calls itself “a wellness tool, not a diagnostic or medical device” (Welltory, overview). HRV artifacts and extra beats explains what beat correction can and cannot fix.

How to take a reading in each app

Kubios HRVElite HRVHRV4TrainingWelltory
Reading length1 to 5 minutes, over 3 recommendedAt least 1 minute, 2.5 to 3 recommended60 seconds; 1, 3 or 5 to chooseAbout 2 minutes by camera; at least 50 heartbeats
WhenIn the morning, on wakingWithin 30 minutes of wakingRight after waking, once a daySame time each morning
PositionReclined or half-reclinedThe same each time, sitting or lyingLying or standingLying, or sitting back in a chair
Before the score settles1 to 2 weeksFirst estimate after 2 days, about 2 weeks4 days for a baselineAsks for morning readings “during a week or two”

From each maker’s pages, 24 October 2026 (see Sources). Welltory counts readings taken between 5:00 and 12:00 as morning ones.

Whichever app you use, keep the same length, position and time of day, and breathe normally. How to take a good HRV reading gives the full routine, and how long until my HRV baseline is reliable? explains the wait.

How to export your data

  • Elite HRV: the data export sits in the app’s settings, below “Set reading reminders”. Elite HRV emails a link that expires after a few hours; the download holds every reading you have taken, one text file per reading, with one RR interval per line and the start time in the file name (Elite HRV, exporting). The paid Personal Pro dashboard also exports calculated values (Elite HRV, pricing).
  • Welltory: sign in to the web app with the same email, choose a chart, and select RR intervals for “a file with raw interval data”, or Export for all the values linked to the chart, as CSV (Welltory, export).
  • HRV4Training: the app exports “via email or Dropbox” (App Store, HRV4Training), and its terms say you can export your data at any time; we found no description of the file. Pro exports athletes’ data as CSV (HRV4Training, Pro guide).
  • Kubios: readings go to Kubios HRV Scientific on a computer. The free Lite version opens the app’s readiness readings and saves the results as CSV or PDF; the full version adds more formats (Kubios, Scientific Lite).

The site’s RR converter reads the RR files of Elite HRV and Welltory, or any other plain list of RR intervals, in your browser, and can save beats from many devices in Kubios’s text format. How to export your HRV data covers watches and rings too.

Price, and what happens when you stop paying

AppTo installPaid options
Kubios HRVFree on iPhone and AndroidScientific $735 a year, $425 academic, before tax; Lite free for non-commercial use; Team Readiness $360 to $1,260 a year
Elite HRVFree on iPhone and AndroidIntegrations $4.99 once; Personal Pro dashboard $8 a month or $76.80 a year; teams $30 to $100 a month
HRV4Training$9.99 on iPhone, $11.99 on Android, oncePro for teams $3 per athlete a month
WelltoryFree, with a 3-day trial of PremiumPremium $99.99 or $119.99 a year, or $299.99 once (App Store in-app purchases)

US App Store, Google Play and the makers’ pages, read on 24 October 2026. We did not find a price for an individual HRV4Training Pro account.

What each maker says about your data:

  • Kubios stores it on servers in the EU or EEA, says it “will not be transferred outside the EU/EEA area”, and says it does not sell personal data (Kubios, privacy policy). The app itself is free, so nothing lapses.
  • Elite HRV: cancelling Personal Pro “will not delete your Elite HRV account information” (Elite HRV, cancel). Its data sits on servers in the United States, and it says it does not “sell, trade, or share any user data with other businesses” unless you start the sharing (Elite HRV, privacy).
  • HRV4Training’s terms, last updated in March 2018, say Pro and Coach subscriptions do not renew by themselves, and “if your Coach or Pro Subscription ends without being renewed, all data in your account … may be lost” (HRV4Training, terms).
  • Welltory: after the trial, the free version keeps a history of 30 days, and “anything older will be deleted unless you export your data in advance” (Welltory, subscription). An account inactive for three years is deleted, and Welltory says it does not sell your data (Welltory, privacy policy).

If you might stop paying, export first. Wearable data rights explains how to ask a company for a full copy.

Head to head

Kubios vs Elite HRV

Both are free and both are at their best with a Polar H10. Pick Kubios if you want a readiness score built from more than one measure, a reading with no strap at all, data kept in the EU or EEA, or a path into research-grade analysis on a computer. Pick Elite HRV if you want a simple 0 to 100 score, guided breathing, every reading’s beats in a file, and the app with the most independent testing, bearing in mind that its iPhone app has not been updated since November 2023.

HRV4Training vs Elite HRV

HRV4Training costs $9.99 or $11.99 once and works without a strap, through the camera, an Apple Watch or an Oura ring; its advice mixes your HRV with how you feel. Elite HRV is free but needs a strap, and gives you the raw beats. With a Polar H10, the one study that tested both found HRV4Training a little closer to the ECG, 4.10% against 7.66%, in only five people (Stone and colleagues, 2021).

Is Welltory accurate?

At rest, in one independent study of 26 professional cyclists, Welltory’s readings matched an ECG. That study does not cover the Stress, Energy, Focus and Health values, whose formulas Welltory does not publish, and readings with movement or an irregular rhythm are less reliable. For a trend, the HRV Score or RMSSD is the part whose input Welltory names.

Apps we left out

Wearable apps from Oura, WHOOP, Garmin, Apple and others measure overnight with no effort and are compared in HRV by device and recovery scores explained. For the cheapest strap-and-app setup, see the cheapest HRV tracking.

hrv.expert also makes its own app, HRV Expert, free for Android and in closed testing on Google Play. We left it out of this comparison because we make it.

When to talk to a doctor

No HRV app diagnoses a heart condition. Talk to a doctor if an app often flags extra beats or poor signal for no clear reason, or if you notice palpitations, dizziness, fainting, chest pain or shortness of breath, whatever the number says.

Common questions

What is the best HRV app?

It depends on your sensor and your purpose. To analyse recordings in depth, Kubios HRV Scientific on a computer. For a daily morning reading with a chest strap, Elite HRV or Kubios HRV, both free. With no extra hardware, HRV4Training through the phone camera, or Kubios HRV with the phone on your chest. For coaches, the team dashboards of Elite HRV, HRV4Training Pro or Kubios Team Readiness.

Is Kubios HRV free?

The Kubios HRV app is free on iPhone and Android, and Kubios HRV Scientific Lite, the desktop analysis software, is free for non-commercial use. The full Kubios HRV Scientific cost $735 a year, or $425 for academic use, before tax, on 24 October 2026.

Which HRV apps work with a Polar H10?

All four. Kubios and Elite HRV name the Polar H10 as their recommended sensor, HRV4Training lists the Polar H7, H9 and H10, and Welltory lists the Polar H10 among the straps it supports, though not the H9. Kubios and Welltory do not support ANT+.

Can a phone camera HRV app be accurate?

At rest, the better camera apps come close to an ECG. In 29 adults, HRV4Training's camera reading of RMSSD differed only trivially from an ECG, and in 26 professional cyclists Welltory's showed no difference from one. A chest strap is still more accurate, and camera readings fail with movement or an irregular heartbeat.

Can I export raw RR intervals from Elite HRV or Welltory?

Yes. Elite HRV emails a link to every reading as a text file of RR intervals, and Welltory's web app downloads RR intervals as a CSV file, one chart at a time. The RR converter on this site reads both.

Sources

  1. Kubios HRV App Kubios
  2. Kubios HRV Scientific Kubios
  3. Kubios HRV Scientific Lite Kubios
  4. Kubios HRV Team Readiness Kubios
  5. Supported devices Kubios
  6. HRV readiness score: monitor stress and recovery with HRV Kubios
  7. PNS and SNS indexes in evaluating autonomic function Kubios
  8. Physiological age: using HRV to assess your overall health Kubios
  9. Accuracy of smartphone-based SCG for HRV analysis Kubios, 2026
  10. Privacy policy Kubios
  11. Kubios HRV: Daily Readiness App Store (US)
  12. Kubios HRV: heart rate variability analysis software Computer Methods and Programs in Biomedicine, 2014
  13. A robust algorithm for heart rate variability time series artefact correction using novel beat classification Journal of Medical Engineering and Technology, 2019
  14. How do you calculate the HRV score? Elite HRV Knowledge Base
  15. What is a good HRV score? Elite HRV Knowledge Base
  16. How is Morning Readiness determined? Elite HRV Knowledge Base
  17. How the HRV baseline works Elite HRV Knowledge Base
  18. How to change Morning Readiness reading time Elite HRV Knowledge Base
  19. Why HRV Morning Readiness? Elite HRV Knowledge Base
  20. Recommended HRV sensors and heart rate monitors Elite HRV Knowledge Base
  21. Is your heart rate monitor compatible with Elite HRV? Elite HRV Knowledge Base
  22. Can I use the app without a heart rate monitor? Elite HRV Knowledge Base
  23. Does Apple Watch work with Elite HRV? Elite HRV Knowledge Base
  24. Overnight or long term readings Elite HRV Knowledge Base
  25. Signal quality: raw vs corrected R-R intervals Elite HRV Knowledge Base
  26. Exporting raw R-R intervals or interbeat intervals (IBIs) Elite HRV Knowledge Base
  27. How does Personal Pro dashboard billing work? Elite HRV Knowledge Base
  28. Is there a premium app version? Elite HRV Knowledge Base
  29. Cancel Personal Pro subscription Elite HRV Knowledge Base
  30. Privacy policy (summary) Elite HRV Knowledge Base
  31. Pricing Elite HRV
  32. Elite HRV: Wellness & Fitness App Store (US)
  33. Elite HRV: Wellness & Fitness Google Play (US)
  34. Validity of the Elite HRV smartphone application for examining heart rate variability in a field-based setting Journal of Strength and Conditioning Research, 2017
  35. Validity of a smartphone application in calculating measures of heart rate variability Sensors, 2022
  36. Validity of Elite-HRV smartphone application for measuring heart rate variability compared to Polar V800 heart rate monitor Journal of Nepal Health Research Council, 2022
  37. Validity and efficacy of the Elite HRV smartphone application during slow-paced breathing Sensors, 2023
  38. Validity and reliability of different smartphones applications to measure HRV during short and ultra-short measurements in elite athletes Computer Methods and Programs in Biomedicine, 2022
  39. Assessing the accuracy of popular commercial technologies that measure resting heart rate and heart rate variability Frontiers in Sports and Active Living, 2021
  40. HRV4Training FAQ HRV4Training
  41. HRV4Training QuickStart guide HRV4Training
  42. Issues in heart rate variability (HRV) analysis: motion artifacts and ectopic beats HRV4Training, 2016
  43. HRV4Training Pro and teams guide HRV4Training
  44. Privacy and terms HRV4Training, 2018
  45. HRV4Training App Store (US)
  46. HRV4Training Google Play (US)
  47. Comparison of heart-rate-variability recording with smartphone photoplethysmography, Polar H7 chest strap, and electrocardiography International Journal of Sports Physiology and Performance, 2017
  48. Heartbeat Report or Nervous System Snapshot: how we interpret heart rate variability metrics Welltory Help Center
  49. Taking measurements with your smartphone camera Welltory Help Center
  50. Is my device compatible with Welltory for HRV measurements and activity tracking? Welltory Help Center
  51. Why you can't use most fitness trackers and smartwatches to measure stress and energy Welltory Help Center
  52. Why do I get no measurement results? Welltory Help Center
  53. How to take accurate heart rate variability measurements? Welltory Help Center
  54. Why trust photoplethysmography, or PPG? Welltory Help Center
  55. Welltory subscription: which one to choose, how to cancel or get a refund, and how to delete your data Welltory Help Center
  56. How to export data from Welltory Welltory Help Center
  57. Overview of the Welltory app Welltory Help Center
  58. Privacy policy Welltory, 2026
  59. Welltory: Stress & Heart Rate App Store (US)
  60. Wavelet analysis and self-similarity of photoplethysmography signals for HRV estimation and quality assessment Sensors, 2021
  61. Heart rate variability: standards of measurement, physiological interpretation and clinical use Circulation (Task Force of the European Society of Cardiology and the North American Society of Pacing and Electrophysiology), 1996

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