Tab Counter

A command-line tool to count the number of browser tabs currently open.

Current Support

Firefox only - This tool currently only supports Mozilla Firefox. Support for other browsers (Chrome, Safari, Edge) may be added in the future.

How It Works

The tool reads Firefox's session store file (a compressed JSON file in mozLz40 format), decompresses it, and counts the total number of tabs across all open windows.

Building

Requirements:

• Go 1.16 or later

go build -o count-firefox-tabs count-firefox-tabs.go

Cross-Platform Builds

# macOS
GOOS=darwin GOARCH=amd64 go build -o count-firefox-tabs-macos count-firefox-tabs.go

# Linux
GOOS=linux GOARCH=amd64 go build -o count-firefox-tabs-linux count-firefox-tabs.go

# Windows
GOOS=windows GOARCH=amd64 go build -o count-firefox-tabs.exe count-firefox-tabs.go

Usage

Simply run the binary:

./count-firefox-tabs

Output:

Firefox tabs open: 42

If Firefox is not running:

Firefox is not running

Platform Support

• macOS: Fully supported
• Linux: Should work (untested) - looks for Firefox profiles in ~/.mozilla/firefox/
• Windows: Should work (untested) - looks for Firefox profiles in %APPDATA%/Mozilla/Firefox/Profiles

Note: The profile location detection currently assumes macOS paths. Cross-platform support would require updating the findFirefoxProfile() function.

How Firefox Session Store Works

Firefox stores your browsing session in compressed files:

• sessionstore-backups/recovery.jsonlz4 - Most recent session data
• sessionstore.jsonlz4 - Backup session data

These files use Mozilla's mozLz40 compression format, which is LZ4 block compression with a custom header containing:

• 8-byte magic number: mozLz40\0
• 4-byte little-endian uncompressed size
• Compressed JSON data

License

MIT