Video Tools
Video Compressor — Shrink Video File Size Online
Compress a video to a smaller file size with three quality presets and an optional resolution cap — processed on your device, never uploaded.
Open toolVideo Converter
Every app seems to want a different video format: editors love MOV, browsers love WebM, and everything on Earth plays MP4. This converter re-wraps and re-encodes your video into the format you actually need — MP4 (H.264, plays everywhere), WebM (VP8, the open web format), MOV (Apple-friendly) or MKV (the archivist's favourite) — entirely inside your browser. The file never leaves your device, so private recordings stay private. Because the conversion re-encodes the picture and sound, the output is a genuine new file in the target format, not just a renamed extension — the trick that produces files which refuse to play.
Choose a file to begin — nothing is uploaded, everything happens on your device.
How to use this tool
- Choose the video to convert.
- Pick the target format: MP4 for everywhere, WebM for the web, MOV for Apple editors, MKV for archives.
- Click Convert video and watch the progress bar.
- Download the converted file and check it plays where you need it.
Worked example
A screen recording a capture app saved as .mkv becomes a universally playable MP4 — same picture and sound, in a container every phone, browser and editor accepts.
Frequently asked questions
Why not just rename .mkv to .mp4?
Because the extension is only a label — the inside of the file (the container and codecs) stays the same, and players that could not read it before still cannot. This tool actually re-encodes the video and audio into the new format, so the result genuinely is an MP4, WebM, MOV or MKV.
Does converting lose quality?
MP4, MOV and MKV outputs use a high-quality setting (CRF 20) that is visually transparent for typical clips. WebM uses VP8 at a generous quality setting. Converting an already-compressed video always costs a little; starting from the best copy you have keeps that loss invisible.
Which format should I choose?
MP4 for sharing, uploads and maximum compatibility. WebM for embedding on websites (smaller, open licence). MOV if an Apple editor or QuickTime workflow asks for it. MKV for keeping a high-quality master in an archive.
Is there a file size limit?
The practical limit is your browser's memory — keep files under roughly 200 MB for a smooth run. Very long videos also take a while: the conversion runs at the speed of your device, and the progress bar shows exactly where it is.