mixpanel-browser/CHANGELOG.md

The official Mixpanel JavaScript browser client library

**2.67.0** (17 Jul 2025)
- Use `get_api_host()` consistently across the SDK
- Include `device_id` in default Feature Flag context
- Track latency props in `$experiment_started` event
- Fix async behavior in `mixpanel.reset()` when a session recording is active
- Fix recorder integration test race conditions

**2.66.0** (8 Jul 2025)
- Add `api_host` configuration option to support different hosts/proxies for different endpoints (thanks @chrisknu)
- Add types.d.ts from existing public repo
- Fix race condition when calling `mixpanel.reset()` while a session recording is active

**2.65.0** (20 May 2025)
- `mixpanel.people.track_charge()` (deprecated) no longer sets profile property
- Adds page height and width tracking to autocapture click tracking
- Session recording now stops when mixpanel.reset() is called
- Support for adding arbitrary query string params to tracking requests (thanks @dylan-asos)
- Feature flagging API revisions
- Whale Browser detection

**2.64.0** (15 Apr 2025)
- Add `record_heatmap_data` init option for Session Recording to ensure click events are captured for Heat Maps
- Initial support for feature flagging

**2.63.0** (1 Apr 2025)
- Update rrweb to latest alpha version
- Refactor SDK build process to rely mainly on Rollup

**2.62.0** (26 Mar 2025)
- Replace UUID generator with UUIDv4 (using native API when available)
- Consistently use native JSON serialization when available
- Fix for session recording idle timeout race condition

**2.61.2** (14 Mar 2025)
- Revert 10ms throttle on enqueueing events to improve tracking reliability on page unload

**2.61.1** (11 Mar 2025)
- Session recording stops if initial DOM snapshot fails
- Errors triggered by rrweb's record function are now caught
- Fix for issue causing opt-out check error messages in `debug` mode

**2.61.0** (6 Mar 2025)
- Session recordings now continue across page loads within the same tab, using IndexedDB for persistence

**2.60.0** (31 Jan 2025)
- Expanded Autocapture configs
- Prevent duplicate values in persistence when using people.union (thanks @chrisdeely)

**2.59.0** (21 Jan 2025)
- Initial Autocapture support
- Block more crawlers (AmazonBot, more Yandex bots)

**2.58.0** (16 Dec 2024)
- Added canvas recording option
- Session Replay checkpoint events now include a starting URL

**2.57.1** (12 Dec 2024)
- Asynchronous abstractions (primarily Promise support) introduced in internal refactor of batch/queue/retry system

**2.57.0** (Dec 2024)
REDACTED

**2.56.0** (4 Nov 2024)
- Recording payloads now include additional metadata: the current URL, library type, and library version.
- Sourcemaps are now generated for the recorder module.
- Added debugging method `mixpanel.get_session_replay_url()` which will return a Mixpanel UI link to the session replay if there is an active recording taking place.
- Refactored session recording module to encapsulate each active recording and its metadata. Added a unit test suite for the new `session-recording.js`.
- Added some additional error handling for when `stopRecording` fails or rrweb silently fails to start recording.
- Removed `record_inline_images` option due to buggy behavior in rrweb.

**2.55.1** (27 Aug 2024)
- Adds a minimum recording length option for session recording
- Fixes and improvements for session recording batcher to support offline queueing and retry
- Fix for query param parsing/escaping
- Support for more UTM tags / click IDs (thanks @aliyalcinkaya)

**2.55.0** (2 Aug 2024)
- Added new build to support native JavaScript modules

**2.54.1** (30 Jul 2024)
- Fixes and improvements for user-idleness detection in session recording

**2.54.0** (23 Jul 2024)
- Provides optional builds without session recording module and without asynchronous script loading.
- Integrates request batcher with session recording module for increased reliability.
- Improved user inactivity heuristic for session recording timeout.
- Adds config options to inline images and collect fonts during session recording.

**2.53.0** (21 Jun 2024)
- Switch to new session-recording network payload format, utilizing client-side compression when available
- Session-recording methods are now available through Google Tag Manager wrapper

**2.52.0** (7 Jun 2024)
- Reverted UTM param persistence change from 2.51.0: UTM parameters are again persisted by default

**2.51.0** (30 May 2024)
- UTM parameter properties are no longer persisted by default
- Existing superproperties persisted in localStorage are now copied back to cookie storage if the library is initialized with cookie persistence (support migrations from localStorage->cookie)
- Added session-recording options `record_block_class`, `record_block_selector`, and `record_mask_text_class`
- Added method `mixpanel.get_session_recording_properties()` for interop with other client-side SDKs

**2.50.0** (26 Apr 2024)
- Initial support for session recording

**2.49.0** (5 Feb 2024)
- SPA support in pageview-tracking
- Support for configurable UTM parameter persistence
- Initial-referrer profile properties are now stored with `set_once` instead of `set`
- Ignore AhrefsSiteAudit crawler

**2.48.1** (14 Nov 2023)
- UTM campaign properties will always be persisted super properties (fixes discrepancy between
minified and unminified package)

**2.48.0** (7 Nov 2023)
- API endpoint routes can now be configured individually (i.e. rename /track, /engage, /groups)
- Event properties object passed to mixpanel.track() will no longer be mutated
- Super properties are now reloaded from persistence when making every tracking call (i.e., kept fresh when another tab/window in the same browser has updated them)
- Extra failsafe behavior for trying to clear queued requests when localStorage doesn't work on startup, e.g., when localStorage is full so writes fail
- Block Chrome-Lighthouse user agent
- Fix for error in add_group() when adding a new group to an existing list

**2.47.0** (27 Apr 2023)
- Collect richer marketing attribution properties for multi-touch attribution
- New implementation of previously-deprecated track_pageview() method and init option to send automatically
- Use performance.now when available for time-based entropy component of UUID-generation (thanks @adrianherd)
- Looser API Host check for default JSON-payload sending to mipxanel.com hosts

**2.46.0** (20 Mar 2023)
- Updates for new identity management system
- More aggressive deduplication within batch sender

**2.45.0** (17 Feb 2022)
- Remove all code related to in-app messaging feature
- Add `error_reporter` config option for user-configurable handling of errors
- Fix missing `var` declarations in HTML script snippet
- Fixes for some batch/retry edge cases where localStorage write failures resulted in duplicate sends

**2.43.0** (5 Jan 2022)
- Support plain JSON tracking payloads (no base64-encoding) and use as default when sending to *.mixpanel.com API hosts

**2.42.1** (20 Dec 2021)
- Add new crawler user agents to blocked list (ahrefsbot, petalbot)

**2.42.0** (9 Nov 2021)
- Make `batch_requests` default-on for all remaining projects
- Replace `unload` event listener with modern alternatives (thanks @JoaoGomesTW)
- Don't retry requests blocked by client (adblockers)
- Retry with backoff after 429

**2.41.0** (28 Jan 2021)
- Remove all code related to Autotrack feature

**2.40.1** (19 Jan 2021)
- Add new crawler user agents to blocked list (pinterest, fb, bingpreview, more google crawlers etc)
- Add debug-mode logging when opt-out/DNT is preventing tracking
- Add more explicit console warning when embed script has been added multiple times on a single page

**2.40.0** (2 Dec 2020)
- Add `persistent` option to `register()`, to support setting superproperties only for the current pageload
- Add before-send `hooks` for transforming/enriching data before it goes over the network
- Add `batch_autostart` config option and `start_batch_senders()` method, to allow extra control over when batches start sending over the network
- Fix request-batching when `sendBeacon` is specified as default API transport
- Increase batch_requests default rollout to 60% of projects

**2.39.0** (17 Aug 2020)
- Escape body of POST requests to ensure valid base64 is sent to APIs (thanks @dpraul)
- Don't opt in to request-batching automatically if using a custom API host (thanks @chriszamierowski)
- Increase batch_requests default rollout to 30% of projects

**2.38.0** (12 Jun 2020)
- Ensure that first-touch referrer/UTM params get saved in superproperty storage even if no events are tracked on the page
- Remove `track_pageview` config option altogether

**2.37.0** (27 May 2020)
- Turn off default pageview-tracking (these mp_page_view events have been dropped server-side for years already)
- Begin rollout of batching as default mode for tracking (10% of projects)

**2.36.0** (7 May 2020)
- Add batch/queue/retry support for event-tracking and people/group profile updates

**2.35.0** (17 Mar 2020)
- Fix cross-subdomain tracking for various edge cases (extra-long TLDs, very short .com/.org domains)
- Add `cookie_domain` config option to allow specifying domain explicitly for cross-subdomain tracking
- Add `cross_site_cookie` config option to add `SameSite=None;Secure` for special integrations (iframes/extensions)
- Return falsey value from track() if navigator.sendBeacon transport fails to enqueue data

**2.34.0** (27 Jan 2020)
- Add config option to allow ignoring DNT browser setting
- Fix for /decide checks failing when lib initialized with sendBeacon transport

**2.33.1** (16 Jan 2020)
- Fix for native arrow-function track() callbacks not firing

**2.33.0** (13 Jan 2020)
- Support optional navigator.sendBeacon transport for network requests
- Add user agent detection for Chromium-based Edge and Samsung Internet

**2.32.0** (16 Dec 2019)
- Default to POST requests for event tracking and profile updates
- Include `$insert_id` with events for deduplication support
- Don't throw exception when decoding malformed URI params
- Notifications test fixes

**2.31.0** (19 Nov 2019)
- Default API server to api-js.mixpanel.com

**2.29.1** (22 Aug 2019)
- Fix race condition with event-triggered in-apps

**2.29.0** (6 Jun 2019)
- `mixpanel.identify()` now sends special `$identify` event for advanced identity management
- Fix extraneous logging for Group API calls

**2.28.0** (9 Apr 2019)
- Support event triggered inapps

**2.27.0** (7 Mar 2019)
- Support cross-subdomain tracking on TLDs longer than 6 chars (thanks @danielbaker)
- Support configurable network protocol for inapp resources (thanks @mkdai)
- Allow inapp links to open in new window/tab via config option (thanks @mkdai)

**2.26.0** (9 Jan 2019)
- Fix minification issue with DoNotTrack browser setting
- Pass flag to backend indicating when $distinct_id might have been set to a pre-existing $distinct_id value instead of a generated UUID (used when resolving aliases)

**2.25.0** (19 Dec 2018)
- Change the behavior of `opt_out_tracking_by_default` to no longer override any existing opt status when the user has an opt-in cookie. It also no longer clears persistence when set to true.
- Create a new param called `opt_out_persistence_by_default` which will determine whether SDK persistence is turned off during initialization

**2.23.0** (23 Oct 2018)
- Track `time` prop automatically with all events recording UTC timestamp (in seconds)
  as the client (browser) sees it. The automatic value can be overridden by setting the
  `time` prop explicitly in tracking calls.
- Set `$user_id` and `$device_id` superprops automatically. This allows finer-grained
  identity management around linking anonymous, logged-in, and logged-out behavior.

**2.22.4** (1 Jun 2018)
- Ensure GDPR cookies are always cleared when possible

**2.22.3** (25 May 2018)
- Bugfix for previous patch

**2.22.2** (25 May 2018)
- Allow GDPR utils to use localStorage instead of cookies

**2.22.1** (22 May 2018)
- Add `xhr_headers` config option for sending extra headers with each request (thanks @austince)

**2.22.0** (3 May 2018)
- Add `cookie_prefix` option to GDPR opt-out utils, allowing customization of cookie name
- Automatically delete user profile and charge data on GDPR opt-out (if specified)

**2.21.0** (20 Apr 2018)
- Add set of opt in/out utility methods in preparation for GDPR
  See https://mixpanel.com/help/reference/javascript-full-api-reference for details

**2.20.0** (6 Apr 2018)
- Remove obsolete autotrack event count metrics

**2.19.0** (21 Mar 2018)
- Clean up handling of JSONDecode errors (thanks @pkaminski)
- Expand server-side `window` polyfill for loading the lib without errors in Node.js

**2.18.0** (27 Feb 2018)
- Prevent Autotrack collecting attrs from input, textarea, select, contenteditable elements
- Change Autotrack $el_text property to not contain text of the target element's children

**2.17.0** (2 Feb 2018)
- Bug fix for Autotrack inadvertently removing form.inputs in certain cases

**2.16.0** (1 Feb 2018)
- Prevent Autotrack collecting attrs from password or hidden fields

**2.15.0** (17 Jan 2018)
- Always track over HTTPS.

**2.14.0** (10 Nov 2017)
- Add `people.unset()`
- Identify Chrome OS (for $os property)
- Bugfix: `register_once()` no longer overwrites previously-registered but falsey values
- Stub parts of DOM API when loading in non-browser environments (thanks @gfx)
- Log full "Implementation error" exceptions when DEBUG mode is on

**2.13.0** (25 Jul 2017)
- Update autotrack editor js path to reflect asset restructuring

**2.12.0** (17 Apr 2017)
- Remove "decide_host" config option
- Bug fix for autotrack editor path

**2.11.1** (14 Apr 2017)
- Autotrack bug fixes

**2.11.0** (16 Feb 2017)
- Remove autotrack backoff functionality

**2.10.0** (19 Jan 2017)
- Identify UC Browser automatically

**2.9.17** (8 Dec 2016)
- In-app notifications now fetch pre-sanitized/url-encoded URLs from the Mixpanel API

**2.9.16** (5 Oct 2016)
Autotrack:
- Bugfix: Check tagNames instead of element references

**2.9.15** (28 Sep 2016)
Autotrack:
- Bugfix: Handle SVG class names properly, remove appHost param

**2.9.14** (23 Aug 2016)
Autotrack:
- Bugfix: Pass appHost from the editor entry so the editor always uses the right appHost

**2.9.13** (23 Aug 2016)
Autotrack:
- Bugfix: Only allow one instance of autotrack to be enabled per project token

**2.9.11/12** (20 Aug 2016)
Autotrack:
- Bugfix: Revert delay navigation changes introduced in 2.9.6

**2.9.10** (16 Aug 2016)
Autotrack:
- Bugfix: use indexOf instead of startsWith

**2.9.9** (16 Aug 2016)
Autotrack:
- Do not delay navigation when the href is just a hash

**2.9.8** (15 Aug 2016)
Autotrack:
- Properly handle getting class names from SVGs
- Add readOnly parameter for Autotrack editor
- Reconstruct Autotrack editor URL to avoid build issue
- More tests

**2.9.7** (11 Aug 2016)
Autotrack:
- Don't attach property keys of stripped values to events
- Tests

**2.9.6** (8 Aug 2016)
Autotrack:
- Delay navigation on link clicks for better tracking

**2.9.5** (27 Jul 2016)
- Autotrack: remove dependency on nearestInteractiveElement and fix a few autotrack edge cases

**2.9.4** (22 Jul 2016)
- Cookie setting fix: return cookie setting function to its previous functionality of using days instead of seconds

**2.9.3** (19 Jul 2016)
- Autotrack: small tweaks

**2.9.2** (19 Jul 2016)
- Autotrack: enabled by default for 100% of projects (still no automatic data collection however)

**2.9.1** (19 Jul 2016)
- Autotrack: enabled by default for 25% of projects (still no automatic data collection however)

**2.9.0** (19 Jul 2016)
- Autotrack: easy and automatic data collection (disabled by default)

**2.8.2** (12 Jul 2016)
- reduce internal stats collection

**2.8.1** (7 Jun 2016)
- make `people` methods queue again between `reset()` and `identify()`

**2.8.0** (6 Jun 2016)
- Collect everything dev
- `track_links()` and `track_forms()` can now take raw elements or element lists in addition to query selectors
- add `reset()` method to handle logout flow (thanks @stefansedich)
- catch exceptions during `_send_request()` (thanks @feychenie)
- fix user agent detection/reporting for Chrome iOS and Firefox iOS

**2.7.3 - 2.7.9** (9 Mar 2016)
- collect stats for internal capacity planning

**2.7.2** (4 Dec 2015)
- full support for NPM installation

**2.7.1** (9 Oct 2015)
- `property_blacklist` config option to prevent sending specified props in `track()`

**2.7.0** (2 Oct 2015)
- support for snippetless synchronous loading via Browserify/Webpack/RequireJS/etc.

**2.6.3** (11 Sep 2015)
- better Windows Phone detection
- enable JS strict mode

**2.6.2** (11 Aug 2015)
- fix relative URL handling in snippet loader

**2.6.1** (7 Aug 2015)
- improve browser/OS detection for MS Edge and IE Mobile (thanks @bohanyang) and Opera
- handle relative URLs better in snippet loader

**2.6.0** (5 Aug 2015)
- add `time_event` method
- update snippet to load mixpanel correctly from cdn when file is opened locally

**2.5.2** (7 Jul 2015)
- automatically track current url
- expose info.properties

**2.5.1** (11 May 2015)
- automatically track browser version (thanks @D1plo1d)

**2.5.0** (5 May 2015)
- add support for localStorage alternative to cookie store (thanks to @sandorfr for initial PR)
- automatically upgrade from existing cookies when localStorage is used

**2.4.2** (23 Mar 2015)
- remove (undocumented) `token` property override in `track()`

**2.4.1** (12 Mar 2015)
- fix for minification issue in `track()` colliding `token` and `ad`

**2.4.0** (10 Mar 2015)
- add `people.union()` (thanks @mogstad)
- remove refs to global RegExp object

**2.3.6** (20 Feb 2015)
- Bower support (thanks @dehau)

**2.3.5** (18 Feb 2015)
- notification caching fix

**2.3.4** (17 Feb 2015)
- ensure notification-tracking on dismissal

**2.3.3** (17 Feb 2015)
- fix Control-click with `track_links()` on Windows/Linux (thanks @pfhayes, [https://github.com/mixpanel/mixpanel-js/issues/20](https://github.com/mixpanel/mixpanel-js/issues/20))

**2.3.2** (9 Dec 2014)
- add `resource_type` to notification-tracking

**2.3.1** (24 Nov 2014)
- fix error when calling `identify()` with no `distinct_id`

**2.3.0** (13 Nov 2014)
- web notifications support