This article explains what’s included in a crash report, how Mozilla uses it, and how you can manage the setting to automatically send crash reports.

What’s included in a crash report?

Crash reports contain technical details about the crash to help Mozilla identify and fix problems in Firefox. Here’s what’s included:

• Crash metadata: Information such as the operating system, app version, device type, and time of the crash. This allows us to narrow down what platforms/user groups are affected by the crash.
• Device memory usage: Information about available memory at the time of the crash. Memory information can be a useful tool to determine whether a crash is caused by low system memory.
• Crash stack traces: Technical details about the code running at the time of the crash. These details guide developers to identify the cause of the crash (whether due to Firefox or third-party code).
• Snapshots from the program memory: Small fragments of memory will be stored in the report to help developers analyze the crash. These might contain private information and will only be accessible by a small number of developers within Mozilla.
• Browsing metadata: The URL that was loaded at the time of the crash may be included if you opt-in to sending it. Sometimes, crashes can only be reproduced by certain webpages, so the URL involved may be valuable to debug the cause of the crash.
• Hardware testing results: We receive a remarkable number of crashes that are simply due to bad hardware. To help identify these cases, we perform simple hardware tests and include results in reports. The tests do not take long and the results do not contain personal identifiable information, however users can opt-out of sending this information.

Some crash reports may include additional debugging information, such as minidumps – small memory snapshots that may contain data such as the list of files that were opened by Firefox at the time of crash or the last URL the user was visiting, to help diagnose crashes. Only a limited number of Mozilla engineers have access to this data.

For a detailed breakdown of the data included in crash reports, visit the Glean Dictionary.

What’s included in a crash ping?

Firefox also sends crash pings, smaller reports containing only the non-identifying metadata about crashes. These are sent automatically unless you opt out of technical and interaction data collection in your settings. While crash pings contain less information than crash reports, they serve an important role in prioritizing debugging efforts (since they give a better estimate of the impact of bugs, not to mention they give insights into background process crashes for which we normally do not receive reports). Crash pings also give a much more accurate representation of the overall stability of Firefox.

For a detailed breakdown of the data included in crash pings, visit the Glean Dictionary.

How does Mozilla use crash reports and crash pings?

Mozilla uses crash reports to identify and fix bugs, improve Firefox’s performance, and make the browser more reliable for users. By analyzing crash data, Mozilla can understand what caused the crash, prioritize fixes, and ensure that future versions of Firefox are less likely to experience similar issues. To process crash reports, Mozilla uses Sentry, a third-party crash analytics service.

How to manage crash report settings

Enable or disable automatic crash reports

By default, Firefox for Android does not automatically send crash reports (unless you specifically chose to automatically send crash reports during your initial onboarding). Focus and Klar do not support automatic crash reports. They ask every time. In Firefox, you can enable or disable this setting at any time by following these steps:

1. Open Firefox and tap the menu button ⋮ next to the address bar.
2. Select Settings.
3. Scroll down to Privacy and security, and tap Data collection.
4. Toggle the Automatically send crash reports option on or off.

   

If automatic crash reports are disabled

If you choose not to turn on automatic crash reports on Android, Firefox will prompt you after a crash and ask if you’d like to send a report. You can choose to submit the report or decline at that time.

Related content

To learn more about how Mozilla handles your data, check out these resources:

• Firefox Privacy Notice
• Manage Firefox data collection and privacy settings
• Manage daily usage ping data collection settings in Firefox
• Firefox Source Docs – Crash Reports on Android