Troubleshooting Common Issues
Solve the most common VideoSOS problems quickly. From browser compatibility and memory errors to failed compression and quality issues, this comprehensive troubleshooting guide helps you diagnose problems, understand error messages, and get back to compressing videos.
Quick Problem Finder
Browser Compatibility Issues
Problem: VideoSOS Won't Load or Shows Blank Page
Possible Causes:
- • Outdated browser version lacking WebAssembly support
- • JavaScript disabled in browser settings
- • Browser extensions blocking scripts or resources
- • Corporate firewall blocking required resources
Solutions:
Update Your Browser
Minimum versions: Chrome 57+, Firefox 52+, Safari 11+, Edge 16+. Update to latest version for best results.
Enable JavaScript
Settings → Privacy & Security → Site Settings → JavaScript → Allowed. VideoSOS requires JavaScript to function.
Disable Extensions Temporarily
Try incognito/private mode (extensions disabled by default) or disable ad blockers and script blockers for videosos.io.
Try Different Browser
Chrome and Firefox have best WebAssembly support. If Safari fails, try Chrome or Firefox.
Browser Recommendations
Chrome / Edge (Chromium)
Fastest WebAssembly performance, best memory handling, most reliable. Recommended for large files and batch processing.
Firefox
Excellent WebAssembly support, strong privacy protections. Slightly slower than Chrome but very reliable.
Safari
Works but can be slower, especially on older Macs. Update to latest macOS and Safari version. May have issues with very large files.
Still Not Loading? Check browser console for error messages (F12 → Console tab). Look for red errors mentioning "WebAssembly", "WASM", or "failed to load". Share these errors when contacting support.
Memory Errors & Crashes
Problem: "Out of Memory" or Browser Tab Crashes
Video compression is memory-intensive, especially for large or high-resolution files. Your browser may run out of available RAM, causing crashes or failures.
Common Symptoms:
- • "Page Unresponsive" dialog appears
- • Browser tab crashes mid-compression
- • Error: "Failed to allocate memory" or "Out of memory"
- • Progress freezes at specific percentage
- • Entire browser becomes slow or unresponsive
Solutions:
Close Unnecessary Tabs and Applications
Free up RAM by closing other browser tabs, applications, and background processes. VideoSOS needs substantial memory for processing.
Use Lower Quality Settings
Switch from High to Medium or Low quality. Lower settings use less memory during compression. You can always reprocess with higher quality if needed.
Reduce Resolution Before Compression
If compressing 4K video, consider processing in chunks or using external tools to downscale to 1080p first, then compress the smaller file.
Restart Browser
Browsers accumulate memory leaks over time. Close and restart your browser, then try compression again. This often resolves intermittent memory issues.
Use Desktop Computer Instead of Mobile
Mobile devices have limited RAM (2-8GB). Desktop/laptop computers (8-32GB+ RAM) handle large videos much better. Use desktop for files over 500MB.
Memory Requirements by Video Size
| Video Size | Resolution | Recommended RAM | Minimum RAM |
|---|---|---|---|
| Under 100MB | Any | 4GB | 2GB |
| 100-500MB | 720p-1080p | 8GB | 4GB |
| 500MB-2GB | 1080p-4K | 16GB | 8GB |
| Over 2GB | 4K | 32GB | 16GB |
Note: These are total system RAM requirements. Browser needs free RAM after OS and other applications. Having more available RAM significantly improves reliability.
Hardware Limitation: For very large files (4K, multiple hours), browser-based compression may not be feasible. Consider desktop software like HandBrake or FFmpeg for files requiring more than 16GB RAM.
Slow Performance Issues
Problem: Compression Taking Extremely Long
Compression speed varies widely based on hardware, video length, resolution, and settings. What's "normal" depends on your specific situation.
Realistic Time Expectations:
Speed Optimization Techniques:
Use Chrome for Fastest Speed
Chrome's V8 JavaScript engine and WebAssembly compiler are typically 20-30% faster than other browsers. Firefox is close second, Safari slower.
Close Other Applications
Give VideoSOS maximum CPU priority. Close video editors, games, browsers with multiple tabs, background apps. Task Manager (Windows) or Activity Monitor (Mac) shows CPU hogs.
Don't Switch Tabs During Compression
Browsers throttle background tabs. Keep VideoSOS tab active and visible for full CPU allocation. Don't minimize browser or switch to other tabs.
Plug In Laptop (Don't Use Battery)
Laptops throttle CPU on battery power to save energy. Plug in AC adapter for full performance. Check power settings are on "High Performance" mode.
Ensure Good Ventilation/Cooling
CPUs throttle when overheating. Use laptop on hard surface (not bed/couch), clean air vents, consider cooling pad. Compression generates heat.
Use Lower Quality for Speed
Low quality compresses 2-3x faster than High quality. If time matters more than maximum quality, choose Medium or Low preset.
Is Your Hardware Too Slow? If compression takes more than 5x the video duration (e.g., 10-min video takes 50+ minutes), your CPU may be too old or underpowered. Consider upgrading hardware or using desktop FFmpeg for better multithreading.
Failed or Stuck Compression
Problem: Compression Fails, Stops, or Never Completes
Common Failure Scenarios:
- • Progress bar reaches certain percentage (e.g., 47%) then stops
- • Error message appears mid-compression
- • Compression appears to complete but no download happens
- • Browser becomes unresponsive and never finishes
- • "Download failed" or "Network error" messages
Diagnostic Steps:
Check Source File Integrity
Try playing the original video in VLC or media player. If it won't play or shows errors, the file is corrupted. VideoSOS can't compress corrupted files.
Verify File Format Support
VideoSOS supports MP4, MOV, AVI, WebM, MKV, FLV, and most common formats. Exotic or very old formats may fail. Try converting to MP4 first using another tool.
Test with Smaller File
Compress a small (under 100MB) test video with same settings. If it works, the issue is file-size related (memory/browser limits). If it also fails, likely a settings or browser issue.
Check Browser Console
Press F12 → Console tab. Look for red error messages when compression fails. Common errors: "SharedArrayBuffer", "wasm", "memory". Copy exact error text for support.
Clear Browser Cache
Settings → Privacy → Clear browsing data → Cached images and files. Old cached FFmpeg versions can cause issues. Clear cache and reload VideoSOS.
Try Different Browser
If Chrome fails, try Firefox. If Firefox fails, try Chrome. Browser-specific bugs occasionally cause failures with certain file types or resolutions.
Specific Error Messages & Solutions
"SharedArrayBuffer is not defined"
Cause: Browser security settings or non-HTTPS connection.
Fix: Ensure you're accessing VideoSOS via HTTPS (https://videosos.io). Check browser is updated. Enable "Shared Memory" in browser flags if needed.
"Failed to compile WebAssembly module"
Cause: Browser lacks WebAssembly support or security extension blocking.
Fix: Update browser to latest version. Disable extensions like NoScript, uBlock Origin temporarily. Try incognito mode.
"Decoder not found" or "Codec not supported"
Cause: Rare or proprietary codec in source video.
Fix: Convert source video to standard H.264 MP4 using VLC or HandBrake first, then compress with VideoSOS.
"Download failed - network error"
Cause: Browser blocking download or insufficient disk space.
Fix: Check disk space on download location. Check browser download settings. Some corporate environments block downloads—try home network.
Format Errors & Quality Problems
Format Not Supported
If VideoSOS rejects your file or says format is unsupported:
- Check file extension matches actual format (some files are mislabeled)
- Use VLC "Convert/Save" to convert to standard MP4 H.264
- Avoid DRM-protected files (iTunes, streaming downloads—these can't be processed)
- Very old formats (MPEG-1, Real Media) may need pre-conversion
Poor Quality or Artifacts
If compressed video has visible quality issues:
- Use higher quality preset (Medium → High) for better results
- Don't compress already-compressed videos (causes generation loss)
- Avoid upscaling resolution (720p → 1080p just makes files bigger, not better)
- Check output on multiple devices—mobile screens hide compression artifacts
Download Problems
Download Button Doesn't Work
Check browser popup blocker. Check download permissions for site. Try right-click → Save As on download button. Verify sufficient disk space in downloads folder.
Downloaded File Won't Play
Try different media player (VLC recommended). Check file size isn't 0 bytes (indicates incomplete download). Reprocess video if file is corrupted.
Download Location Unknown
Check browser downloads (Ctrl+J in Chrome/Firefox). Check default download folder in Settings → Downloads. Search computer for recently modified .mp4 files.
Using Browser Console for Debugging
Browser developer console shows technical error messages that help diagnose problems. Learning to access and read console output enables you to troubleshoot issues yourself or provide detailed error reports.
Opening Browser Console
Windows/Linux: Ctrl + Shift + J | Mac: Cmd + Option + J
Or: Menu (⋮) → More Tools → Developer Tools → Console tab
Windows/Linux: Ctrl + Shift + K | Mac: Cmd + Option + K
Or: Menu (☰) → More Tools → Web Developer Tools → Console
Windows: Ctrl + Shift + J | Mac: Cmd + Option + J
Or: Menu (⋯) → More Tools → Developer Tools → Console tab
Mac: Cmd + Option + C
First enable: Preferences → Advanced → Show Develop menu in menu bar
Reading Console Messages
ℹ️ Blue/Info messages
Informational messages. Generally safe to ignore. Show normal operation events.
⚠️ Yellow/Warning messages
Non-critical issues. May indicate performance problems or deprecated features but usually don't prevent operation.
❌ Red/Error messages
Critical errors that prevent functionality. These are what you need when troubleshooting failures. Copy exact error text when reporting issues.
When to Contact Support
If you've tried troubleshooting but still have issues, contact support with:
- Browser name and version (Help → About)
- Operating system (Windows 10/11, macOS, Linux)
- Source video format, resolution, and file size
- Settings used (quality preset, output format)
- Error messages from console (copy/paste or screenshot)
- Steps to reproduce the problem
Preventing Problems Before They Happen
Best Practices
- ✓ Keep browser updated to latest version
- ✓ Close unnecessary tabs before compressing
- ✓ Start with small test files when learning
- ✓ Use recommended browsers (Chrome/Edge)
- ✓ Ensure sufficient free RAM and disk space
- ✓ Verify source videos play correctly first
- ✓ Don't compress already-compressed videos
Common Mistakes
- ✗ Using outdated browser versions
- ✗ Processing huge files on low-RAM devices
- ✗ Switching tabs during compression
- ✗ Using laptop on battery power
- ✗ Blocking JavaScript or WebAssembly
- ✗ Expecting instant results on long videos
- ✗ Not checking source file quality first
Additional Resources
Still need help? Check these resources for more information: