Summary of Changes

Addressed "No remote snapshots found" issue by implementing a robust, compressed, and backward-compatible storage system for Firefox Sync.

Problem Identification

Firefox sync provides a limited 2GB space per user which is used for all sync purposes. A tiny part of this storage is also provided for extensions. Extensions have further limitation to the number of items and the size of each item that can be stored (8Kb). Crossing these limits are throwing storage errors by the service. This is a plausible cause for some users not able to see their remote tab groups.

Solution:

Implement a custom chunk/de-chunk algorithm and a compression/decompression algorithm to alleviate the storage limitation issues.
Handling backwards compatibility has been the tougher part. It would be a pain to have users with existing working installation face issues. So, added in backward compatibility and eventual cleanup logic. I hope this ensures a pain free upgrade process for existing working installations.

Key Features

• Data Chunking: Implemented a mechanism to split large tab group snapshots into multiple pieces, bypassing the 8KB per-item limit in Firefox Sync storage.
• Native Compression: Integrated the CompressionStream API to compress snapshots using Gzip. This reduces data size by up to 97%, significantly saving storage quota.
• Smart Compatibility Layer: Added logic to automatically choose the most compatible storage format:
• V1 (Legacy): Used for small snapshots (< 8KB) to ensure older versions of the extension can still read them.
• V2/V3 (Modern): Used for larger data, employing chunking and compression as needed.

️ Technical Improvements

• Code Unification: Refactored background.js to share core synchronization logic with background.logic.js, eliminating duplicate code and reducing bugs.
• Robust Reassembly: Updated both the background logic and the popup UI to transparently detect, reassemble, and decompress snapshots regardless of their version.
• Automatic Cleanup: Added logic to remove obsolete data chunks when a snapshot's size decreases, preventing storage bloat.

Verification & Testing

• New Test Suites: Created compatibility.test.js and updated utils.test.js and background.logic.test.js to cover all new scenarios.
• Quota Simulation: Verified that the extension now successfully handles payloads that previously triggered QuotaExceededError.
• Full Regression: Confirmed that all 35 project tests pass, ensuring no regressions in security or core tab-grouping logic.

Changes

• New Feature: Mirror Mode: Added a "Mirror" toggle in the UI that allows replacing local tab groups with remote snapshots instead of just merging them.
• UI Enhancements: Updated the popup interface with a new sync control layout, including a Mirror Mode warning indicator and improved device settings.
• Background Logic: Updated synchronization logic to handle the mirror flag and prevent storage exhaustion via title truncation.

Release Notes (v1.3.1)
•Added light/dark theme toggle in the popup UI.
•Displayed extension version in the popup footer.
•Optimized group card lookup performance by switching to a Map.
•Capped device name length at 32 chars to prevent storage bloat.
•Improved tab comparison and removed n+1 queries - less load on firefox and quick processing.

The code is now open-source. Please check it out here: https://github.com/sudhir-asuracore/firefox-tab-group-sync
A shortcut is added to the bottom right corner of the popup - it will redirect you to the above project where you can report issues, request features or submit your own improvements to it.

Would be glad if you can report any issues or improvements you think would be nice.

Release Notes:
* Moved to OpenSource
* Removed one permission which turns out we dont need. (it was 'unlimited storage' and did nothing to our plugin functionality). So dropped it.
* Cleaned up the code a little (Am new to JS. So everytime i look at the code, I feel unsatisfied with it)

It was unclear if tabs and groups were already syncd to my local browser. Enhanced the popup to display a green hue for groups which are already in sync and allowing selection + clicking sync for groups which are yet to be syncd.

Minor timestamp display changes - instead of a timestamp, it now says MMM-DD, YYYY (eg: Dec 12, 2025 instead of 12-12-2025)

Popup now displays tabs and groups only if there is a difference to be pulled/sync'd.

Updated sync consolidation