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Crashlytics for web apps

If your Android and iOS apps report crashes to Firebase Crashlytics, the obvious next step is the same for the web app. There is no such step: Crashlytics does not run in a browser. Here is what teams on Firebase do instead, without giving up Crashlytics for mobile.

By · Published Nov 1, 2026

Drafted with AI assistance, reviewed and published by Jose Franco.

Crashlytics has no web SDK

Firebase describes Crashlytics as crash reporting for Apple, Android, Flutter and Unity, and its setup picker offers iOS+, Android, Android NDK, Flutter and Unity. The web is not on the list. The feature request on the Firebase JavaScript SDK, “FR: Web Observability in Crashlytics”, has been open since April 2018 and has 935 reactions and 86 comments. Firebase Performance Monitoring and Analytics do run on the web, which is why people expect Crashlytics to.

So a Firebase web app has no built-in place for its JavaScript errors to go. Most of them never reach a server, because they happen in a visitor's browser, and you only hear about them when someone writes in.

Keep Crashlytics for mobile

You do not need to move your mobile apps off Crashlytics. It is free and it works for what it covers. Send only the web half somewhere else: the browser app, and optionally the Cloud Functions behind it.

The usual way is Sentry's open-source JavaScript SDK, a widely used browser error reporter. It sends to any service that speaks its protocol, and RealUptime Errors does: you install @sentry/browser (or the package for your framework), and give it the DSN from your Errors project. The Firebase setup guide walks through Firebase Hosting and Cloud Functions step by step.

What web error tracking adds

  • Grouped issues instead of a log: the same error from a thousand visitors is one issue with a count, a first-seen and a last-seen.
  • Readable stack traces: upload source maps per release and minified frames point back to your source lines.
  • Context: browser, page, release, environment and the breadcrumbs leading up to the error.
  • Alerts when it matters: new issues, regressions and spikes to email, Slack, Discord, Google Chat or a webhook, scoped to production if you want.

What it costs

Crashlytics costs nothing on either Firebase plan, and RealUptime Errors does not try to replace that. Errors is free for 10,000 events a month with no card, and the same account includes Monitor for uptime checks on your Firebase Hosting site, Status for a public status page, and Outages, which already tracks Firebase's own incidents.

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