Google Health API reference

Daily Heart Rate Variability: the Google Health API daily-heart-rate-variability data type

Read from Google’s documentation on 2026-10-17 · discovery document revision 20261014 · Google’s data-types page last updated 2026-10-06

Daily Heart Rate Variability (daily-heart-rate-variability) is a Daily data type in the Google Health API. Google's data-types table lists list and reconcile for it under the .health_metrics_and_measurements.readonly and .health_metrics_and_measurements.writeonly scopes. The table marks it with webhook support. Google's Fitbit migration table maps the Fitbit Web API's HRV summary data to it.

Daily Heart Rate Variability at a glance

From the Daily Heart Rate Variability row of Google’s data-types table, joined to the discovery document’s DataPoint schema.

Display name: Daily Heart Rate Variability
dataType (in endpoint URLs): daily-heart-rate-variability
filter parameter: daily_heart_rate_variabilityGoogle: “The identifier separated by underscores (for example, active_minutes) used as the value for the dataType filter parameter in daily rollup and rollup requests.”
Record type: Daily — Google: “Represents measurements aggregated or recorded on a daily basis.”
Storage resolution: not stated in Google’s table
Webhook support: Yes · automatic-subscription token WEBHOOK_DATA_TYPE_DAILY_HEART_RATE_VARIABILITY
True zeros support: Not marked in Google’s table
Channel: v4
DataPoint field: DataPoint.dailyHeartRateVariability → DailyHeartRateVariabilityIts description: “Optional. Data for points in the daily-heart-rate-variability daily data type collection.”
Compatible devices: 23 in Google’s table

Operations and request paths

The operations Google’s table lists for daily-heart-rate-variability, each matched to its users.dataTypes.dataPoints method in the discovery document. The path is the documented path template (the method’s flatPath on https://health.googleapis.com/) with {dataTypesId} filled in as daily-heart-rate-variability. Google on {user}: “The {user} can be either the alias me or the authenticated user's numeric Health User ID (retrieved via GetIdentity).”

Table lists	Method	Documented path template
`list`	`list`	`GET https://health.googleapis.com/v4/users/{usersId}/dataTypes/daily-heart-rate-variability/dataPoints`
`reconcile`	`reconcile`	`GET https://health.googleapis.com/v4/users/{usersId}/dataTypes/daily-heart-rate-variability/dataPoints:reconcile`

Every method, and how many of the data types list it: the methods overview.

Scopes

The scopes Google’s table lists for daily-heart-rate-variability, as full URLs, with the consent text Google’s Scopes page gives each. Every Google Health API scope.

Scope	Access	Google’s permission text
`https://www.googleapis.com/auth/googlehealth.health_metrics_and_measurements.readonly`	read	See your Google Health health metrics and measurement data.
`https://www.googleapis.com/auth/googlehealth.health_metrics_and_measurements.writeonly`	write	Add health metric and measurements data to Google Health, and edit or delete the data it adds.

Fields of Daily Heart Rate Variability

The schema the discovery document gives DataPoint.dailyHeartRateVariability, required fields first. Types are as the discovery document states them; the label is the word Google’s description opens with. The schemas its fields refer to follow, one level deep.

DailyHeartRateVariability — Google: “Represents the daily heart rate variability data type. At least one of the following fields must be set: - average_heart_rate_variability_milliseconds - non_rem_heart_rate_beats_per_minute - entropy - deep_sleep_root_mean_square_of_successive_differences_milliseconds”

Field	Type	Google’s description
`date`Required	`Date`	Required. Date (in the user's timezone) of heart rate variability measurement.
`averageHeartRateVariabilityMilliseconds`Optional	`number/double`	Optional. A user's average heart rate variability calculated using the root mean square of successive differences (RMSSD) in times between heartbeats.
`deepSleepRootMeanSquareOfSuccessiveDifferencesMilliseconds`Optional	`number/double`	Optional. The root mean square of successive differences (RMSSD) value during deep sleep.
`entropy`Optional	`number/double`	Optional. The Shanon entropy of heartbeat intervals. Entropy quantifies randomness or disorder in a system. High entropy indicates high HRV. Entropy is measured from the histogram of time interval between successive heart beats values measured during sleep.
`nonRemHeartRateBeatsPerMinute`Optional	`string/int64`	Optional. Non-REM heart rate

`Date`

Google: “Represents a whole or partial calendar date, such as a birthday. The time of day and time zone are either specified elsewhere or are insignificant. The date is relative to the Gregorian Calendar. This can represent one of the following: * A full date, with non-zero year, month, and day values. * A month and day, with a zero year (for example, an anniversary). * A year on its own, with a zero month and a zero day. * A year and month, with a zero day (for example, a credit card expiration date). Related types: * google.type.TimeOfDay * google.type.DateTime * google.protobuf.Timestamp”

Field	Type	Google’s description
`day`	`integer/int32`	Day of a month. Must be from 1 to 31 and valid for the year and month, or 0 to specify a year by itself or a year and month where the day isn't significant.
`month`	`integer/int32`	Month of a year. Must be from 1 to 12, or 0 to specify a year without a month and day.
`year`	`integer/int32`	Year of the date. Must be from 1 to 9999, or 0 to specify a date without a year.

Fitbit Web API predecessor

Google’s Fitbit Web API → Google Health API data-type table maps HRV summary to daily-heart-rate-variability.

Fitbit Web API scopes Google maps to daily-heart-rate-variability’s scopes: blood_glucose, heartrate, oxygen_saturation, respiratory_rate, temperature, weight.

Google’s full Fitbit Web API mapping tables · the migration playbook

Where Google’s pages disagree

Published as found, with the texts that disagree; nothing here is corrected by us.

Rollup missing from the table
The discovery document's DailyRollupDataPoint.heartRateVariabilityPersonalRange is returned when rolling up daily-heart-rate-variability, but the table does not list dailyRollup for daily-heart-rate-variability.
- the v4 discovery document: “Returned by default when rolling up data points from the daily-heart-rate-variability data type, or when requested explicitly using the heart-rate-variability-personal-range rollup type identifier.”
- Google's data-types page: “list, reconcile”

Compatible devices

The 23 devices Google’s table lists as able to record and sync daily-heart-rate-variability.

Fitbit Air
Fitbit Alta HR
Fitbit Blaze
Fitbit Charge 2
Fitbit Charge 3
Fitbit Charge 4
Fitbit Charge 5
Fitbit Charge 6
Fitbit Inspire 2
Fitbit Inspire 3
Fitbit Inspire HR
Fitbit Ionic
Fitbit Luxe
Pixel Watch
Pixel Watch 2
Pixel Watch 3
Pixel Watch 4
Fitbit Sense
Fitbit Sense 2
Fitbit Versa
Fitbit Versa 2
Fitbit Versa 3
Fitbit Versa 4

Google’s documentation

Related on this site

HRV API: How to Get Heart Rate Variability Data — the metric on every platform this site covers, each type quoted in its platform's own words
Google Health API webhooks
Verification and rate limits
The Fitbit Web API turn-off

Questions

Which OAuth scopes does the Google Health API daily-heart-rate-variability data type need?

Google's data-types table (read 2026-10-17) lists https://www.googleapis.com/auth/googlehealth.health_metrics_and_measurements.readonly and https://www.googleapis.com/auth/googlehealth.health_metrics_and_measurements.writeonly for daily-heart-rate-variability. The Scopes page's consent text: .health_metrics_and_measurements.readonly, "See your Google Health health metrics and measurement data."; .health_metrics_and_measurements.writeonly, "Add health metric and measurements data to Google Health, and edit or delete the data it adds."

Can apps write daily heart rate variability data to the Google Health API?

Not according to Google's data-types table, read 2026-10-17: it lists only list and reconcile for daily-heart-rate-variability, and no create, update or batchDelete operation.

How do you aggregate daily-heart-rate-variability data with the Google Health API?

Not with rollUp or dailyRollUp, going by Google's data-types table: it lists only list and reconcile for daily-heart-rate-variability. The discovery document disagrees: its DailyRollupDataPoint.heartRateVariabilityPersonalRange is returned when rolling up daily-heart-rate-variability, but the table does not list dailyRollup for daily-heart-rate-variability. Test before relying on either reading.

What did the Google Health API daily-heart-rate-variability data type replace in the Fitbit Web API?

Google's Fitbit Web API migration table maps the Fitbit Web API's "HRV summary" to daily-heart-rate-variability. The Fitbit Web API scopes Google maps to its scopes: blood_glucose, heartrate, oxygen_saturation, respiratory_rate, temperature and weight.

Other health metrics and measurements data types

All health metrics and measurements data types →

Sources checked

Google Health API data types — last updated 2026-10-06 · read 2026-10-17
Google Health API discovery document (v4) — revision 20261014 · read 2026-10-17
Scopes — last updated 2026-10-09 · read 2026-10-17
API specifications — last updated 2026-09-22 · read 2026-10-17

Google’s text is quoted for identification; each guide page’s footer reads: “Except as otherwise noted, the content of this page is licensed under the Creative Commons Attribution 4.0 License, and code samples are licensed under the Apache 2.0 License.”. Generated from Google’s pages by scripts/fetch-google-health-api.mjs, not typed by hand; Google’s documentation remains the authority.

← All Google Health API data types