STEP-BY-STEP GUIDE

Return profile settings to defaults with Firefox Refresh

Troubleshooting guideSources checked: 2026-09-054 stepsFaultNote editorial team

What to do first

Move to a new profile without extensions and customizations, confirm retained items, then restore only the settings you need.

This is a general troubleshooting guide, not an announcement of a current outage.

Affected products and symptoms

Product: Mozilla Firefox Desktop
Versions and conditions: Firefox Desktop; available in Firefox 150 or later when using the new profile management

Symptoms

Firefox problems continue after isolating extensions and settings

Causes and conditions

Extensions, damaged settings, or customizations in the profile may interfere with operation.

Before you start

Check Firefox account synchronization
Back up important bookmarks
Record extensions, site permissions, certificates, and toolbar settings

Precautions

Extensions, themes, site permissions, modified settings, added search engines, and similar customizations are removed
Old Firefox Data contains sensitive information and must be handled carefully
With new profile management, the feature may be unavailable before Firefox 150

Tools and official pages used in this guide

Refresh Firefox ↗See step 2 ↓
Review what data is retained and which settings are removed before proceeding.

Procedure overview created by FaultNote. Read the precautions and full instructions before changing settings. Read the full steps

Step-by-step instructions

01
Diagnose first
#
Open Menu > Help > Troubleshoot Mode and reproduce the same operation with extensions and related features temporarily disabled. If it does not improve, another cause may make Refresh ineffective, so record the error and URL.
If there are many extensions or accessibility settings, save their list and settings as images or notes. Refresh removes extensions, themes, permissions, and modified settings.
Use the three-line menu at the upper right to open the listed items and distinguish the normal window from the diagnostic window. Use the same URL, zoom level, video position, and operation before and after the change.
02
Start Refresh
#
In normal mode, open Menu > Help > More troubleshooting information and select Refresh Firefox on the right. Select Refresh Firefox again in the confirmation dialog; Firefox then closes.
If normal startup fails, the same feature is available from Troubleshoot Mode. The button may be unavailable before Firefox 150 when using the new profile management.
Improvement in diagnostic mode does not establish that the GPU alone is responsible. Extensions, themes, and hardware acceleration change together, so return to normal mode and test candidates individually.
Official links for this step
- Refresh Firefox
  Review what data is retained and which settings are removed before proceeding.
Check before continuing
The official Refresh Firefox page or signed package opens, and its product, OS, and version requirements match this computer.
03
Review and finish
#
After Firefox creates a new profile and restarts, review the imported-items list and select Finish. Choose whether to restore prior windows and tabs, then check bookmarks, history, and passwords.
Old Firefox Data on the desktop is a copy of the old profile and contains sensitive information. Keep it securely until recovery has been verified.
After changing a setting, close every Firefox window and restart. Save the Graphics section of about:support if needed, and restore any setting that does not help before proceeding.
04
Restore only required items
#
Before reinstalling extensions, reproduce the affected URL and operation to establish a clean state where the symptom is absent. Then restore required extensions, site permissions, and toolbar settings one at a time, checking after every change.
Remove the item added immediately before the problem returned. If information is missing, follow Mozilla's profile-recovery procedure and copy only required files from Old Firefox Data. Overwriting the entire new profile can restore the problem too.
When finished, open an ordinary page and video as well as the affected URL. Completion means rendering works, crashes do not recur, and any responsible extension has been identified.
Completion criteria: bookmarks, history, and passwords remain, and the symptom is resolved before extensions are restored. If unmet, do not repeat the same operation; follow the next branch: with Firefox closed, use Mozilla's old-profile recovery procedure to restore only required items from Old Firefox Data; do not overwrite the entire new profile.
Check before continuing
Decision: establish a symptom-free baseline before reinstalling extensions, then restore required extensions, permissions, and toolbar settings one at a time. Remove the item that precedes recurrence and copy only required files from Old Firefox Data if data is missing.

Check the result

Bookmarks, history, and passwords are retained
The symptom is resolved before extensions are restored

If the problem continues

With Firefox closed, follow Mozilla's old-profile recovery procedure and restore only required items from Old Firefox Data; do not overwrite the entire new profile
Keep the old profile and compare it using Profile Manager

Scope of this guide

Troubleshooting guide — Refresh retains items such as bookmarks while removing extensions and modified settings.

Frequently asked questions

What remains after Refresh?

Bookmarks, history, passwords, cookies, form autofill data, the personal dictionary, and similar data are retained.

Official sources and dates

Source publication or resolution date: 2026-04-09. Sources checked: 2026-09-05. The check date is not the date the problem first occurred. Interface labels can vary between versions and display languages.

Related troubleshooting guides

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