JavaScript SDK ⁠-⁠ Initializing the SDK

The following line will install the tracker and with it the SDK for you to take advantage of all tracker features.

npm i @openreplay/tracker

When instantiating OpenReplay’s tracker, there are several configuration options you can provide to customize many aspects of the recording and the recording experience.

You must set the projectKey option in the constructor. You can get this value from your OpenReplay dashboard under ‘Preferences > Projects’.

Single Page Applications (SPA)

Section titled Single Page Applications (SPA)

If your website is a Single Page Application (SPA) use the below code:

import OpenReplay from '@openreplay/tracker';
const tracker = new OpenReplay({
  projectKey: PROJECT_KEY
tracker.start(); // returns a promise with session info (sessionID, sessionHash, userUUID)

Otherwise, if your web app is Server-Side-Rendered (SSR) (i.e. NextJS, NuxtJS) use the below snippet. Ensure tracker.start() is called once the app is started (in useEffect or componentDidMount).

import OpenReplay from '@openreplay/tracker/cjs';
const tracker = new OpenReplay({
      projectKey: PROJECT_KEY,
function MyApp() {
  useEffect(() => { // use componentDidMount in case of React Class Component
    tracker.start(); // returns a promise with session info (sessionID, sessionHash, userUUID)
  }, [])
import OpenReplay from '@openreplay/tracker/cjs';
const tracker = new OpenReplay({
      projectKey: PROJECT_KEY,
      ingestPoint: "", // when dealing with the self-hosted version of OpenReplay
      capturePerformance: true,
      __DISABLE_SECURE_MODE: true // for local testing

There are a set of options you can pass to the constructor. Only projectKey is required.

  • projectKey: string The ID of the project you’re tracking.
  • sessionHash?: string The hash of the initial session. This is useful when sessions traverse different subdomains on your web app but you want to stitch them into a single recording. In case it’s not possible to continue the session (doesn’t exist or is finished), the tracker will automatically start a new one. It’s also returned on stop(). More details on this here.
  • ingestPoint?: string Your OpenReplay domain (i.e., to which the tracker will be sending events. This is optional for OpenReplay Cloud users. Default: (which points to OpenReplay Cloud).
  • revID?: string The revision ID of your web app. Useful when searching for issues happening on a specific release version.
  • resourceBaseHref?: string Refers to the publicly accessible domain where assets (styles, fonts and icons) could be fetched by OpenReplay. Since they’re required for proper session replay, this option is useful to get around the limitation of having your site (and therefore assets) hosted in a private domain. Example:
  • captureIFrames?: boolean For capturing all of the same-domain iFrames in your web app. If you wish to track a specific iFrame, then instead simply add the data-openreplay-capture HTML attribute to the <iframe> tag. Default: true.
  • disableClickmaps?: boolean For disabling css selector calculation (used in click maps). Default: false.
  • verbose?: boolean For enabling logs. Default: false.
  • autoResetOnWindowOpen?: boolean Enable this option to reset the sessionID when opening a new tab from your application. This overwrites the method to avoid duplicate sessionIDs due to shared session storage between browser tabs. Default: false.
  • forceSingleTab: boolean Disables the multi-tab recording capability which stitches user sessions, conducted across multiple tabs, into a single replay. Instead, by enabling this option, sessions captured in different browser tabs will be recorded in separate recordings. Default: false.
  • disableStringDict: boolean Disables the string dictionary logic (for optimizing storage) in recordings. Default: false.
  • fixedCanvasScaling: boolean Forces canvas images to be rendered with pixel density of 1 instead of devicePixelRatio. (lowers the potential quality of an image to make end result smaller in size)
  • disableCanvas?: boolean Disables recording of canvas elements
  • assistSocketHost?: string Can be used to set a specific host for assist plugin connection
  • respectDoNotTrack?: boolean Do not start tracker if the do-not-track flag is enabled in the user’s browser. Default: false.
  • obscureTextEmails?: boolean Obscures emails in text elements. Emails will be converted to a random chain of asterisks. Default: true.
  • obscureTextNumbers?: boolean Obscures numbers in text elements. Numbers will be converted to a random chain of asterisks. Default: false.
  • obscureInputEmails?: boolean Obscures emails in input fields. Email values will be converted to a random chain of asterisks. Default: true.
  • defaultInputMode?: 0 | 1 | 2 Default capture mode for input values. Respectively: plain, obscured or ignored. Default: 1 (obscured).

Note that excluded data is obscured or suppressed before sending the data to OpenReplay servers. Changes applied to the above options cannot be retroactive and will only apply to newly collected data. See Sanitize Data for more details.

  • consoleMethods?: Array<'log' | 'info' | 'warn' | 'error' 'debug' | 'assert'> | null Specifies the list of console methods to capture. Default: ['log', 'info', 'warn', 'error', 'debug', 'assert']
  • consoleThrottling?: number Max number of captured console entries per second. Default: 30.
  • captureExceptions?: boolean Captures JavaScript exceptions and stacktraces. Default: true.
  • captureResourceTimings?: boolean Logs resource timings. Default: true.
  • capturePageLoadTimings?: boolean Logs page load timings. Default: true.
  • capturePageRenderTimings?: boolean Computes page rendering metrics such as Speed Index, Visually Complete or Time To Interactive. Requires captureResourceTimings = true. Default: true.
  • capturePerformance?: boolean For capturing performance metrics such as framerate, CPU and memory consumption. Default: true.

The network option relates to capturing network requests and payloads for fetch and XHR.

network?: {
    failuresOnly: boolean;
    sessionTokenHeader: string;
    ignoreHeaders: Array<string> | boolean;
    capturePayload: boolean; // make sure you sanitize your data before enabling it
    sanitizer: (RequestResponseData) => RequestResponseData | null;
    captureInIframes: boolean;
    axiosInstances: AxiosInstance[];
    useProxy?: boolean;
    tokenUrlMatcher?: (url: string) => boolean;

See Network Options for examples and more details on how to redact sensitive data.

The canvas option relates to capturing canvas/WebGL elements:

canvas?: {
  disableCanvas?: boolean
  fixedCanvasScaling?: boolean
  useAnimationFrame?: boolean
  fileExt?: 'webp' | 'png' | 'jpeg' | 'avif'

See Canvas and WebGL for how to enable this capability and more details on the available options.

The mouse option relates to capturing selectors for clicks to build clickmaps.

  disableClickmaps?: boolean
  minSelectorDepth?: number
  nthThreshold?: number
  maxOptimiseTries?: number
  • disableClickmaps?: boolean Disables selector calculation entirely. Default: false.
  • minSelectorDepth?: number Minimum length of an optimized selector (default 2). Example: body > div > div > p => body > p
  • nthThreshold?: number Number of selector tries before falling back to nth-child selectors. This is an expensive operation and may incur a significant overhead, do not set higher than 2000. Default: 1000.
  • maxOptimiseTries?: number Number of tries to optimize and shorten the selector. Default: 10 000.
  • connAttemptCount?: number Max number of retries when tracker’s HTTP requests fail to reach the backend. Default: 10.
  • connAttemptGap?: number Duration between each retry attempt (expressed in ms). Default: 8000.
  • onFlagsLoad callback used to perform an action once feature flags are loaded (every time).
 flags?: {
   onFlagsLoad?: (flags: IFeatureFlag[]) => void
// ...
interface IFeatureFlag {
  key: string
  is_persist: boolean
  value: string | boolean
  payload: string
  • __DISABLE_SECURE_MODE?: boolean For allowing insecure connection between tracker and backend on sites without SSL. This should be used for development purposes only. Default: false.