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    2.5.0-1 • Public • Published

    Bugsnag Notifier for JavaScript build status

    The Bugsnag Notifier for JavaScript gives you instant notification of errors and exceptions in your website's JavaScript code.

    Bugsnag's JavaScript notifier is incredibly small, and has no external dependencies (not even jQuery!), and works in all browsers (even mobile browsers!), so you can safely use it on any website.

    Learn more about Bugsnag's JavaScript error monitoring solution. Bugsnag captures errors in real-time from your web, mobile and desktop applications, helping you to understand and resolve them as fast as possible. Create a free account to start capturing errors from your applications.

    How to Install

    Include bugsnag.js from our CDN in the <head> tag of your website, before any other <script> tags.

    <script src="//"

    Make sure to set your Bugsnag API key in the data-apikey attribute on the script tag, or manually set Bugsnag.apiKey.

    Now all uncaught exceptions will be sent to Bugsnag, without any further work from you.

    Sending Caught Exceptions or Custom Errors

    You can easily tell Bugsnag about caught exceptions by calling Bugsnag.notifyException:

    try {
      // Some code which might throw an exception
    } catch (e) {

    Since many exceptions in JavaScript are named simply Error, we also allow you to provide a custom error name when calling notifyException:

    try {
      // Some code which might throw an exception
    } catch (e) {
      Bugsnag.notifyException(e, "CustomErrorName");

    You can also send custom errors to Bugsnag without any exception, by calling Bugsnag.notify:

    Bugsnag.notify("ErrorName", "Something bad happened here");

    Both of these functions can also be passed an optional metaData object as the last parameter, which should take the same format as metaData described below.


    You can set the severity of an error in Bugsnag by including the severity option when notifying bugsnag of the error,

    Bugsnag.notify("ErrorName", "Something bad happened here", {}, "error");

    Valid severities are error, warning and info.

    Severity is displayed in the dashboard and can be used to filter the error list. By default all crashes (or unhandled exceptions) are set to error and all Bugsnag.notify calls default to warning.

    Cross-domain errors

    Browsers obscure some error messages that happen when scripts are loaded cross-domain. This is for security, but is annoying when hosting javascript on a CDN. You can tell if this happens because Bugsnag will log to your console:

    [Bugsnag] Ignoring cross-domain script error.

    You can fix this by loading your javascript using CORS. We have detailed instructions for setting this up.

    Browser Support

    Bugsnag can automatically notify you of unhandled exceptions in all versions of all browsers (yes, even IE 6!). Some browsers let us do even more, and internally we have 3 tiers of higher quality support:

           | Tier A | Tier B | Tier C | Supported

    -----------|:------:|:------:|:------:|:---------: iOS | 7+ | 6 | 3-5 | all Android | 4.0+ | | 2.2-3 | all Blackberry | | 10 | | all IE | 8+ | | | all Firefox | 17+ | 6-16 | 3-5 | all Safari | 7+ | 6 | 5 | all Chrome | 14+ | | | all Opera | 13+ | 10-12 | | all Cumulative | 82.9% | 91.2% | 96.4% | 100%

    Most users are on tier A or B browsers (91.2%), errors from these browsers are deduplicated most effectively, and there's lots of debugging information available.

    A number of people are still on tier C (%5.2%) or worse (3.6%) browsers (though those proportions will diminish over time). We can still notify you of problems in these browsers, though the quality is significantly lower.

    If you're only targetting up-to-date users, you can tell Bugsnag to only report errors from modern browsers by going to "Settings -> Error Handling"



    Set your Bugsnag API key. You can find your API key on your dashboard.

    <script src="//"

    In situations where Bugsnag is not in its own script tag, you can set this with:

    Bugsnag.apiKey = "YOUR-API-KEY-HERE";


    By default, we will automatically notify Bugsnag of any JavaScript errors that get sent to window.onerror. If you want to stop this from happening, you can set autoNotify to false:

    <script src="//"

    In situations where Bugsnag is not in its own script tag, you can set this with:

    Bugsnag.autoNotify = false;


    By default, the notify request will be made via temporary javascript image object. This does not work in Chrome apps and extensions where XHR needs to be used. If you want to use Bugsnag with XHR, just set notifyHandler to xhr:

    <script src="//"

    In situations where Bugsnag is not in its own script tag, you can set this with:

    Bugsnag.notifyHandler = "xhr";


    Information about the current user. This data will be sent to Bugsnag with exception reports so that you can see who was affected by a particular error and search for problems seen by a given user.

    Bugsnag.user = {
      id: 7,
      name: "Conrad Irwin",
      email: ""


    Set additional meta-data to send to Bugsnag with every error. You can use this to add custom tabs of data to each error on your Bugsnag dashboard to help you debug.

    This should be an object of objects, the outer object should represent the "tabs" to display on your Bugsnag dashboard, and the inner objects should be the values to display on each tab, for example:

    Bugsnag.metaData = {
      account: {
        name: "Bugsnag",
        plan: "premium",
        beta_access: true


    If you would like to distinguish between errors that happen in different stages of the application release process (development, production, etc) you can set the releaseStage that is reported to Bugsnag.

    Bugsnag.releaseStage = "development";

    By default this is set to be "production".


    By default, we will notify Bugsnag of exceptions that happen in any releaseStage. If you would like to change which release stages notify Bugsnag of errors you can set notifyReleaseStages:

    Bugsnag.notifyReleaseStages = ["development", "production"];


    Setting the appVersion lets you see at a glance when errors first and last happened in your code. You can do this either in the script-tag:

    <script src="//"

    Or in javascript:

    Bugsnag.appVersion = "2.0.14";


    To have more fine grained control over what errors are sent to Bugsnag, you can implement a beforeNotify function. If you want to halt the notification completely, return false from this function.

    Bugsnag.beforeNotify = function(payload) {
      // Example: Only notify Bugsnag of errors in `app.js` or `vendor.js` files
      var match = payload.file.match(/app\.js|vendor\.js/i);
      return !!(match && match[0].length > 0);

    You can modify the payload or metaData by editing the parameters.

    Bugsnag.beforeNotify = function(payload, metaData) {
      // Filter out sensitive information
      payload.url = "";

    The payload parameter contains the error's name, message, file and lineNumber where available, as well as some additional fields that we either show on your Bugsnag dashboard, or use for grouping.


    If the metaData hash has a key groupingHash it will be used to override the default grouping on Exceptions with the same grouping hash will be grouped together into one error. You should not normally need to change this.

    Bugsnag.notifyException(e, {groupingHash: e.message});

    By default errors will be grouped by the statement in your code that raised the error. We try to fetch the javascript and use the surrounding code to identify the statement, but if that's not possible we fall back to using line number and filename as an approximation.


    The endpoint option causes the Bugsnag notifier to send errors to a different web address. By default the address is set to, but you can change it to point to an on-premise installation of Bugsnag:

    Bugsnag.endpoint = "https://bugsnag.local:49000/js";


    By default, Bugsnag sets the projectRoot to the current host address (protocol & the domain). For example, is the projectRoot for all errors that occur within the domain.

    Bugsnag.projectRoot = "";


    By default, Bugsnag sets the context to the current page's pathname, otherwise referred to as location.pathname. Note: location.pathname does not include any search parameters or the page's fragment identifier.

    Bugsnag.context = "/path/to/my/page.php";

    noConflict Support

    Bugsnag has a noConflict function for removing itself from the window object and restoring the previous binding. This is intended for use in environments where developers can't assume that Bugsnag isn't in use already (such as 3rd party embedded javascript) and want to control what gets reported to their Bugsnag account.

    The object returned from noConflict() is the full Bugsnag object so can be used in the same way:

    var myBugsnag = Bugsnag.noConflict();
    // window.Bugsnag is now bound to what it was before the bugsnag script was loaded.
    myBugsnag.apiKey = "my-special-api-key";
    try {
      // highly volatile code
    } catch (e) {
      myBugsnag.notifyException(e, "OhNoes");

    AMD/CommonJS support

    Bugsnag can be loaded as-is using an AMD or CommonJS compatible loader. This means you can use it with tools like RequireJS and Browserify directly. If you want to load Bugsnag from the CDN but load the rest of your code using AMD, then you should ensure Bugsnag is required before the rest of your code.

    If you load Bugsnag after the rest of your code, and your AMD loader leaks the global define function then you may see the (harmless) error message: "Mismatched anonymous define() module". To fix this, load Bugsnag before the rest of your code.

    Script tag support

    By default Bugsnag sends the contents of inline script tags on the page to our servers to help with analysis and debugging. If you don't want this to happen, set inlinescript to false.

    <script src="//"

    Notifying Bugsnag about jQuery Ajax errors

    If you're using jQuery to send Ajax requests, we recommend hooking Bugsnag up to notify about ajaxError's.

    $( document ).ajaxError(function(event, jqxhr, settings, thrownError) {
      Bugsnag.notify("AjaxError", thrownError);

    Source Maps

    Bugsnag supports source maps to reverse JavaScript minification. These can either be fetched automatically or manually uploaded using the Bugsnag Source Map API. See the Bugsnag source map documentation for details.

    Advanced hosting

    We will occasionally update bugsnag-2.js on the CDN to improve the quality of our notifier without breaking backward compatibility. If you need assurance that the javascript will never change, feel free to include the specific version directly.

    <script src="//"

    If you have specific requirements for Javascript, you're welcome to host versions of bugsnag-js on your own site or CDN.

    If you'd like to avoid an extra blocking request, you can include the javascript in your asset compilation process so that it is inlined into your existing script files. The only thing to be sure of is that Bugsnag is included before your onload handlers run. This is so that we can report stacktraces reliably.

    Rate limiting

    By default only 10 errors are allowed per page load. This is to prevent wasting a user's bandwidth sending thousands of exceptions to Bugsnag. If you have a long-running single page app, you can reset this rate-limit from your router by using:


    Browser Extensions

    Bugsnag's backend automatically ignores errors if they appear to come from browser extensions, since these errors usually aren't actionable for site owners and often aren't related the current page's code at all.

    If you have a special case where you want to know about errors that come from extensions — for example, if you are attempting to monitor a browser extension itself — you may need to modify the error stacktrace you send to Bugsnag to work around this feature. For example, for a Chrome extension, you might add something like this to your beforeNotify function:

    Bugsnag.beforeNotify = function (error, metaData) {
        error.stacktrace = error.stacktrace.replace(/chrome-extension:/g, "chromeextension:");

    To monitor an extension, you may also need to use XHR to notify Bugsnag of errors to work around content security policy restrictions for images loaded by extensions.

    Reporting Bugs or Feature Requests

    Please report any bugs or feature requests on the github issues page for this project here:



    The Bugsnag JavaScript notifier is free software released under the MIT License. See LICENSE.txt for details.




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