Yes! All test results are stored only on your device in your browser's local storage. Nothing is sent to external servers except during the speed test itself (which only connects to test servers to measure your connection).

• No account required - use immediately
• No tracking or analytics on your data
• Complete privacy - no one can see your results
• Your data, your control - export or delete anytime

Partially. You need an internet connection to run speed tests (since you're testing your internet connection!), but you can view your test history offline.

All your past test results, notes, favorites, and settings are stored locally and accessible without an internet connection.

Your test history will be deleted. Since all data is stored locally in your browser, clearing browser data removes it.

To prevent data loss:

• Export your test history before clearing (History → Export All)
• Create a full backup (Settings → Backup & Restore)
• Re-import your data after clearing if needed

Very accurate when used properly. This app uses industry-standard testing methods:

• Multiple parallel connections to saturate bandwidth
• Binary data transfer (no compression)
• Real server latency testing
• No caching that would skew results

For best accuracy:

• Use a wired Ethernet connection
• Close other internet-using apps
• Run multiple tests and average results
• Use Standard or Advanced mode

This is very common. Here are the main reasons:

• "Up to" speeds: ISPs advertise maximum possible speeds, not guaranteed speeds
• WiFi limitations: Wireless is slower than wired Ethernet
• Network congestion: Speeds drop during peak hours (6-11 PM)
• Old equipment: Router or modem may be outdated
• Multiple devices: Other devices using your connection simultaneously
• ISP throttling: Some ISPs slow specific traffic types

💡 Tip: Run tests with Ethernet during off-peak hours (early morning) to see your true maximum speed.

Recommended testing frequency:

• Monthly: General monitoring to track long-term trends
• Weekly: If experiencing connection issues
• Before/After changes: Router upgrades, ISP changes, moving equipment
• Different times: Test at various times to understand daily patterns

Testing too frequently (multiple times per hour) won't provide useful information since speeds naturally fluctuate.

Speed variations are normal and occur due to:

• Network congestion: More users online = slower speeds
• WiFi interference: Walls, distance, and other devices affect wireless
• Server location: Tests to closer servers are usually faster
• Background activity: Other apps using your connection
• Weather conditions: Can affect wireless and satellite connections
• ISP management: Traffic shaping and prioritization

Small variations (±10%) are normal. Larger variations suggest investigating the cause.

Yes, speed tests use data to measure your connection. Approximate data usage per test:

• Quick mode (5s): 50-100 MB
• Standard mode (10s): 100-200 MB
• Advanced mode (15s): 200-400 MB

⚠️ Warning: Don't run tests frequently on metered/limited data plans (mobile data, satellite internet, etc.)

Yes! The app works on phones and tablets. However, keep in mind:

• Mobile results will be limited by WiFi or cellular speeds
• Mobile results are often lower than wired desktop tests
• Still useful for comparing your mobile connection over time
• Watch your data usage if testing over cellular

The responsive design works well on all screen sizes.

Generate shareable certificates based on your speed test performance:

Three test modes with different durations and connection counts:

• ⚡ Quick (5s) - Fast test with 2 connections. Good for quick checks, less accurate.
• 🎯 Standard (10s) - Balanced test with 4 connections. Recommended for most users - good accuracy without long wait.
• 🚀 Advanced (15s) - Thorough test with 8 connections. Most accurate results, takes longest.

More connections and longer duration = more accurate but slower. Start with Standard mode.

Try these solutions:

1. Check your internet connection is active
2. Refresh the page (press F5)
3. Try a different browser (Chrome, Firefox, Edge)
4. Clear browser cache and reload
5. Disable browser extensions temporarily
6. Check if firewall is blocking the test

Possible causes:

• Browser storage was cleared
• Using incognito/private browsing mode
• Using a different browser than before
• History filter is active (check dropdown)
• History limit was reached and old tests auto-deleted

Prevention:

• Regularly export your history (History → Export All)
• Create backups (Settings → Create Backup)
• Avoid clearing browser data

Settings should save automatically. If they're not:

1. Check if browser allows local storage
2. Disable incognito/private mode
3. Check browser storage isn't full
4. Allow the site to store data in browser settings
5. Try refreshing and changing settings again

Note: Settings apply instantly and don't require a page refresh.

Common issues:

• You're typing in a text field (shortcuts disabled in input fields)
• Browser extensions are intercepting shortcuts
• Using wrong modifier key (try Ctrl vs Cmd on Mac)
• Some shortcuts only work in specific views (e.g., Ctrl+E only in History)

Press Ctrl + / to see all available shortcuts and their current context.

If you see error messages during testing:

1. Check if you're actually online (try loading another website)
2. Test server might be temporarily down - wait a few minutes and try again
3. Refresh the page and restart the test
4. Try using a different browser
5. Check if your firewall or antivirus is blocking the connection

For export issues:

• Make sure your browser allows file downloads
• Check if popup blockers are preventing the download
• Try a different export format (CSV vs JSON)

For import issues:

• Verify the file isn't corrupted (can you open it?)
• For JSON imports, ensure the file format is correct
• Try exporting a test first to see the correct format
• Make sure you're selecting the right file type

Try these solutions:

1. Click the theme toggle switch in Settings (sun/moon icon)
2. Refresh the page after changing theme
3. Clear browser cache and try again
4. Check if browser extensions are interfering with the theme
5. Try in incognito mode to rule out extension conflicts

Note: Theme preference is saved automatically and should persist across sessions.

SpeedTest works on all modern browsers:

• Chrome (recommended) - Version 90+
• Firefox - Version 88+
• Safari - Version 14+
• Edge - Version 90+
• Opera - Version 76+

For best results, keep your browser updated to the latest version.

Yes! SpeedTest uses industry-standard testing methods:

• Multiple parallel connections to saturate bandwidth
• Binary data transfer (no compression or caching)
• Real server latency measurement
• Statistical analysis for accuracy

Results are comparable to professional speed testing services. However, accuracy depends on:

• Your testing conditions (wired vs WiFi)
• Network congestion at test time
• Background applications and device performance

The conversion between these units:

Examples:

• 100 Mbps = 12.5 MB/s
• 500 Mbps = 62.5 MB/s
• 1 Gbps = 125 MB/s

💡 Tip: ISPs advertise in Mbps, but downloads show MB/s. You can change the unit display in Settings.

All your data is stored locally in your browser using:

• IndexedDB: For test history, notes, and favorites
• LocalStorage: For settings and preferences

This means:

• ✅ Complete privacy - data never leaves your device
• ✅ Works offline for viewing history
• ✅ No server storage or accounts needed
• ⚠️ Data is browser-specific (not synced across browsers)
• ⚠️ Clearing browser data will delete history