MOV to MP4 converter
iPhone and Mac recordings come out as MOV. Windows apps, Android phones, many upload forms and some TVs expect MP4.
What happens to your MOV
If the MOV holds H.264 or HEVC with AAC audio (almost all iPhone clips do), the converter re-wraps the streams into MP4 without re-encoding. That usually takes seconds and loses nothing. ProRes or PCM sources are re-encoded to H.264 + AAC.
Tip: An iPhone HEVC clip stays HEVC after a remux. If the target device cannot play HEVC, tick "Re-encode to H.264" for maximum compatibility.
How to convert MOV to MP4
- Drop your MOV file on the box above, or tap it to pick one. The engine (about 31 MB) loads once per visit.
- The converter reads the file's streams and shows which codecs are inside.
- Keep the defaults, or pick a quality and resolution.
- Press the button, wait for the progress bar, then download your MP4.
Questions
Does converting MOV to MP4 reduce quality?
Not when the streams are copied (remuxed): the video data is byte-for-byte the same. Quality only changes if you force a re-encode.
Why is my iPhone MOV not playing on Windows?
Usually because it is HEVC (H.265) video and Windows lacks the paid HEVC extension. Convert with 'Re-encode to H.264' ticked.
Will my iPhone HDR video stay HDR?
Yes if it is remuxed (the default): the 10-bit HEVC stream and its HDR tags are copied untouched. Re-encoding to H.264 here produces 8-bit video without HDR-to-SDR tone mapping, so colours can look flat.
How do I stop my iPhone recording MOV/HEVC?
Settings › Camera › Formats › Most Compatible records H.264. The files are still .mov, but they remux to an MP4 that plays everywhere.
Can I convert several MOV files at once?
One at a time in the browser, to keep memory use safe on phones. Remuxes take seconds each.
Is my MOV file uploaded?
No. The MOV is read from your device by FFmpeg running as WebAssembly in the page, and the MP4 is written back to your device. No server ever receives it.
Is there a size limit for MOV to MP4?
We set none. The practical limit is browser memory: roughly 2 GB of output on a computer, and much less on phones.
MOV and MP4 are siblings, not rivals
MP4 (ISO/IEC 14496-14) was built on Apple's QuickTime file format, so a MOV and an MP4 share the same structure of nested "atoms": a moov index and an mdat block of compressed data. Both boxes hold the same codecs. That is why MOV to MP4 is nearly always a remux: FFmpeg reads the H.264 or HEVC packets out of one box and writes them into the other without decoding a single frame.
Try your own clip's combination
Pick what's inside your MOV (an iPhone clip is usually HEVC + AAC) and see whether it can simply be moved into MP4:
Your file
Convert to
Remux: copy both streams into the new box
The HEVC video and AAC audio are allowed in MP4, so nothing is decoded. It takes seconds and the picture is bit-for-bit identical.
What is inside an iPhone MOV
Swipe the table sideways to see all columns.
| iPhone setting / mode | Video | Audio | MOV to MP4 here |
|---|---|---|---|
| Camera › Formats › High Efficiency (default) | HEVC (H.265), 8-bit SDR | AAC | Remux in seconds. Still HEVC afterwards |
| High Efficiency + HDR Video on (iPhone 12 and later) | HEVC 10-bit, HLG / Dolby Vision | AAC | Remux keeps HDR intact. Re-encoding to H.264 gives 8-bit video that can look flat or washed out (no HDR-to-SDR tone mapping in the browser engine) |
| Camera › Formats › Most Compatible | H.264 | AAC | Remux, and it plays everywhere |
| ProRes (Pro models) | Apple ProRes 422 HQ | PCM | Re-encoded to H.264 + AAC. Files are huge, so use a computer |
| Cinematic mode, Spatial video | HEVC (+ depth / second-eye data) | AAC | Main picture converts; depth or 3D layers are dropped |
| Screen recordings | H.264 or HEVC | AAC (if mic on) | Remux |
Codec details follow Apple's own support notes on HEIF/HEVC capture and HDR video. Check your clip: the converter shows the codecs as soon as you drop the file in.
When a remux is enough, and when it isn't
- Enough: the app or site accepts MP4 files but refuses
.mov(upload forms, some Android galleries, many web apps). Leave "Re-encode" unticked. - Not enough: the file opens but shows a black picture, plays sound only, or says "codec not supported". The problem is HEVC, not the box. Tick Re-encode to get H.264, which older Windows PCs without the HEVC extension, Firefox on many systems, older smart TVs and most editing web apps can play.
- Also re-encoded: ProRes or PCM sources, any resolution change, rotation or deinterlacing.
Can I just rename .mov to .mp4?
Often it plays, because the structure is the same. But the file still declares itself as QuickTime (its ftyp brand is qt ), may carry QuickTime-only timecode and metadata tracks, and usually has its index at the end, which delays web playback. A remux writes a proper MP4 header, tags HEVC as hvc1 so Apple devices keep playing it, and moves the index to the front (+faststart). It costs a few seconds and nothing else.
What a remux keeps and drops
| Kept | Every video frame bit for bit, the audio track, resolution, frame rate, HDR signalling, rotation flag |
|---|---|
| Dropped | Extra QuickTime data tracks (timecode, location/camera metadata tracks, Live Photo pairing, Cinematic depth), subtitles |
| Size | Within a few KB of the original. To make it smaller you need compression; SqueezeVideos targets exact sizes |
Background: containers vs codecs · MP4 vs MOV compared · H.264 vs H.265 on SqueezeVideos · HEVC to H.264 converter