SpeedCheck – Internet Speed Test od Fabian Zhlsdorf

SpeedCheck – Internet Speed Test lets you measure your internet speed directly from the Firefox toolbar – no new tab required.

Features:

One-click speed test: download, upload & ping
Clean, animated gauge UI with real-time results
Connection rating (Excellent / Good / Slow)
Test history (last 5 results stored locally)
Dark & light theme with auto-detection
100% private – no data leaves your browser
Powered by Cloudflare's global network for accurate, reliable measurements.

Visit speed-check.net for detailed analysis, jitter tests, and more.