No, absolutely not. This tool processes everything locally in your browser using HTML5 and JavaScript. Your video never leaves your device — it's not uploaded, stored, or transmitted anywhere. This ensures complete privacy and security.

Most common video formats are supported: MP4, WebM, MOV, AVI, MKV, FLV, WMV, and 3GP. Support depends on your browser's video codec capabilities. Chrome and Firefox offer the broadest format support. For best results, use MP4 (H.264) files.

Browsers use the MediaRecorder API for local video processing, which outputs WebM format (the standardized open format for web video). While your input may be MP4, the exported clip will be WebM. Most modern video players support WebM. If you need MP4 output, you can use a free converter like HandBrake after downloading.

The tool provides frame-accurate trimming within your browser's capabilities. You can set start and end times down to hundredths of a second. Use the sliders for rough selection and the precise time input fields for exact frame positioning. Keyboard shortcuts (I for in-point, O for out-point) make precision editing even faster.

Yes! The tool is fully responsive and works on iOS and Android devices. However, exporting large video files on mobile may be slower due to hardware limitations. For best mobile experience, use short clips (under 2 minutes) and choose Medium or Low quality settings.

Exporting uses real-time playback recording (1× speed) to ensure high-quality output with synchronized audio. A 30-second clip takes approximately 30 seconds to export. This method preserves audio-video sync better than frame-by-frame canvas rendering. For longer clips, we recommend trimming in smaller segments.

Space — Play/Pause video  |  I — Set In point (start of clip)  |  O — Set Out point (end of clip)  |  ← → — Skip 1 second back/forward  |  Shift + ← → — Skip 5 seconds back/forward  |  Enter — Preview clip

There's no hard limit, but we recommend files under 2GB for smooth performance. Larger files may cause memory issues in the browser. If your video is very large, consider compressing it first or splitting it into smaller segments before trimming.