Updated June 2026 · ConvertCabin Guides
MP4 vs WebM vs MOV
MP4, MOV and WebM are containers — wrappers around the actual video and audio streams. They overlap a lot, which is why files often need converting between them depending on where they are going.
What each one is for
- MP4 — the universal default. H.264 video inside an MP4 plays on practically every phone, TV, editor and messaging app.
- MOV — Apple's QuickTime container, what iPhones and many cameras record. Excellent quality, but less universally accepted outside Apple software.
- WebM — an open, royalty-free format (VP8/VP9 or AV1) designed for the web. Great for browser video, less so for editors and phones.
Side by side
| MP4 | MOV | WebM | |
|---|---|---|---|
| Compatibility | Universal | Apple-first | Web/browsers |
| Typical source | Everywhere | iPhone, cameras | Web, screen recorders |
| Editing support | Excellent | Excellent on Mac | Limited |
| Royalty-free | No (H.264) | No | Yes |
| Best for | Sharing anywhere | Recording on Apple gear | Embedding on websites |
When to convert
Convert MOV to MP4 when an iPhone clip will not play or upload somewhere. Convert WebM to MP4 when a web download will not open in an editor or on a phone. Go the other way — to WebM — when you want a smaller, royalty-free file to embed on a site.
These use a local copy of FFmpeg that runs inside your browser, so even large videos are converted on your device without uploading.
Frequently asked questions
Is MP4 or MOV better?
For quality they are similar — both commonly hold H.264 video. MP4 wins on compatibility, so it is the better choice for sharing; MOV is fine if you stay in Apple software.
Why will my MOV not play on Windows?
Older Windows setups may lack the codec or QuickTime support a MOV needs. Converting to MP4 (H.264) almost always fixes it.
Is converting between video formats lossless?
Re-encoding involves some quality loss, though at sensible settings it is hard to notice. Only a straight stream copy (same codec) is truly lossless.