Convert · runs on your device
Convert MOV to MP4 in your browser
Drop your MOV files in and Video Mender rewrites them as MP4 inside this tab. An iPhone or QuickTime MOV normally holds H.264 or HEVC video that MP4 can carry as-is, so the frames are copied rather than re-encoded and the job takes seconds.
Nothing is uploaded
Drop video files here
MOV
Plays on effectively every browser, phone, TV and editor when it holds H.264 and AAC.
The universal baseline. Hardware decoding exists on essentially every device sold since 2010.
Files smaller than the limit are left alone. Capping usually looks better than lowering the bitrate.
MOV and MP4 are siblings. The MP4 specification was built on the QuickTime file format, and both store video as tracks inside the same kind of box structure. What usually stops a MOV playing somewhere is the extension and the container brand, not the video inside it — and those are exactly the parts a rewrap changes.
So for most files this page does not convert the picture at all. It reads each MOV, confirms the video is H.264, HEVC or MPEG-4 and the audio is AAC or MP3, and copies those streams into a fresh MP4 container. Nothing is decoded, so the result looks identical to the source and is about the same size. The queue shows "Fast rewrap" on any file that will take this path before you press Start.
Some MOV files hold things MP4 has no standard place for. ProRes, DV and Motion JPEG video from cameras and editing software are re-encoded to H.264, and uncompressed PCM audio becomes AAC. Each of those files is labelled before it runs, so you know which ones will take minutes rather than seconds. Everything happens in this browser tab; the MOV is never uploaded.
What this actually does to your file
Rewrap or re-encode
Rewrap runs whenever the MOV holds H.264, HEVC or MPEG-4 video with AAC or MP3 audio, which covers iPhone recordings and most QuickTime exports. ProRes, DV and Motion JPEG video are re-encoded to H.264 because MP4 has no standard way to carry them. PCM audio is converted to AAC while compatible video is still copied.
Quality
On the rewrap path the video and audio are copied unchanged, so quality is identical to the MOV. Files holding ProRes, DV, Motion JPEG or PCM are re-encoded, which is lossy; the quality slider sets how much.
- iPhone MOV files are usually HEVC. A rewrap keeps that HEVC video, so the MP4 still needs an HEVC-capable player. If it must play on older Windows PCs or Android phones, set the video codec to H.264 — that re-encodes and takes much longer.
- Only the first video and first audio track are kept. Timecode, Live Photo and other metadata tracks in camera MOV files are dropped.
- A rewrapped MP4 is about the same size as the MOV. To make it smaller, use the MOV compressor instead, which re-encodes at a lower bitrate.
- HDR and 10-bit footage that has to be re-encoded is written as 8-bit H.264, which can change how the colours look. A rewrap leaves it untouched.
How to convert MOV to MP4
- Drop your MOV files onto the queue — iPhone videos, QuickTime recordings or exports.
- Check each badge: "Fast rewrap" copies the video untouched, "Re-encode" means the codec had to change.
- Leave the output as MP4. Set the video codec to H.264 only if the MP4 must play on devices without HEVC support.
- Press Start, then download each MP4 as it finishes or select several and take a ZIP.
Where the result plays
Checked against the containers and codecs this page produces, stated conservatively.
| Target | Works | Detail |
|---|---|---|
| Windows | Yes | MP4 opens in the built-in players and in editors that ignore .mov. HEVC video may need the HEVC extension from Microsoft; H.264 never does. |
| Android | Yes | MP4 is the native gallery format. HEVC plays on most recent phones; H.264 plays on all of them. |
| Chrome, Edge, Firefox | Yes | MP4 with H.264 plays inline. A MOV is often downloaded instead of played. |
| Websites and upload forms | Yes | Many forms accept .mp4 but reject .mov by extension alone, even when the video inside is identical. |
| Apple devices | Yes | Both formats already play on macOS and iOS; converting is for everything else. |
The formats involved
| Format | Read | Write | What it is |
|---|---|---|---|
| MOV | Yes | Yes | Apple QuickTime. Structurally a close cousin of MP4, which is why MOV files can often be rewrapped to MP4 with no re-encode. |
| MP4 | Yes | Yes | The MPEG-4 Part 14 container. It is a wrapper, not a codec — an MP4 usually holds H.264 or HEVC video with AAC audio. |
| MKV | Yes | Yes | Matroska. The most permissive common container: it will carry almost any codec, plus multiple audio tracks, chapters and subtitles. |
| WebM | Yes | Yes | A deliberately restricted Matroska profile for the web: VP8/VP9/AV1 video with Opus or Vorbis audio, and nothing else. |
Tested limits
Ceilings derived from the engine's 4 GiB address space and enforced per job, not a marketing claim of unlimited.
| Limit | Desktop | iPhone / iPad | Why |
|---|---|---|---|
| File size — rewrap | 1.3 GiB | 384 MiB | Rewrapping never decodes a frame, so it tolerates far larger files. |
| File size — re-encode | 1.0 GiB | 256 MiB | Decoding holds uncompressed frames in memory, which is the real constraint. |
| Clip length — re-encode | 4:00:00 | 30:00 | Beyond this, progress reporting and memory behaviour stop being dependable. |
| Resolution — re-encode | 4096 × 2160 | 1920 × 1080 | A 4K frame is about 12 MB decoded, before the encoder allocates anything. |
If something goes wrong
The MP4 plays on my Mac but not on a Windows PC.
The video is almost certainly HEVC, copied unchanged from an iPhone. Install the HEVC extension on that PC, or convert again with the video codec set to H.264 so the file plays everywhere.
One file says "Re-encode" when the others say "Fast rewrap".
That MOV holds a codec MP4 does not carry, typically ProRes from an editing export or Motion JPEG from an older camera. It will still convert, but it is a full re-encode and takes far longer than the rewrapped files.
The MP4 is the same size as the MOV.
That is what a rewrap does — the compressed video is copied, not re-compressed. If you need a smaller file, use the MOV compressor, which re-encodes at a lower bitrate.
Your video never leaves this device
This is a structural property of the application, not a policy we ask you to take on trust. There is no upload endpoint, no API route and no server action anywhere in the codebase, so there is nowhere for a video to be sent even by mistake.
- Conversion runs in WebAssembly inside this browser tab. The engine is served from this domain and loaded only when you start a job.
- The Content-Security-Policy restricts network connections to this origin, so the page is not permitted to contact a third party at all.
- Nothing is stored. Close the tab and every queued file and finished output is gone — which is also why you should download results before you leave.
- There are no accounts and no AI. Anonymous page views are counted — which page, roughly what country, what kind of device — and nothing whatsoever about your files.
The repository contains a test that fails the build if any media byte is passed to fetch, XMLHttpRequest, sendBeacon or a WebSocket. See the privacy page for how that is verified.
Questions
Does converting MOV to MP4 lose quality?
Not when the file is rewrapped, which is what happens to most iPhone and QuickTime MOV files. The compressed frames are copied into the MP4 unchanged. Quality is only affected when the MOV holds a codec such as ProRes that must be re-encoded, or when you ask for H.264, a lower resolution or a different frame rate.
What is the difference between MOV and MP4?
Both are containers built on the same QuickTime-derived structure, and both commonly hold H.264 or HEVC video with AAC audio. MOV is the Apple format and can carry more professional codecs such as ProRes; MP4 is the international standard and is recognised by far more software, websites and devices.
Can I convert iPhone videos to MP4 here?
Yes. iPhone recordings are MOV files holding HEVC or H.264 video with AAC audio, so they rewrap to MP4 directly. On an iPhone itself the browser engine has tighter limits — rewraps up to about 384 MB per file — so very long clips are easier to convert on a computer.
Can I just rename a .mov file to .mp4?
Often it will appear to work, because the internal structure is so similar, but the file still identifies itself as QuickTime and some players, editors and upload forms check that. A rewrap writes a real MP4 container in about the same time it takes to copy the file.
Is my MOV uploaded to convert it?
No. The conversion runs in WebAssembly inside this browser tab. The application has no upload endpoint, and a test in the repository asserts that no media bytes leave the page.
Can I convert many MOV files to MP4 at once?
Yes. Add as many as you like; compatible files rewrap in seconds each and any that need re-encoding are labelled before the queue starts. Download them one by one or as a ZIP.
Related tools
- CompressMOV compressorDrop your .mov files in, set a target size or quality, and Video Mender re-encodes them locally — MOV recordings usually shrink by 60–80% because cameras record at far higher bitrates than playback needs.
- ConvertMP4 to MOVMP4 and MOV are both ISO base media files, so Video Mender simply rewrites the container: your MP4 becomes a QuickTime MOV in seconds with the video and audio streams copied bit for bit.
- ConvertHEVC to MP4HEVC is a codec, not a container, and MP4 can already hold it — so "HEVC to MP4" means one of two different jobs, and this page lets you choose the right one explicitly.
- ConvertBatch converterQueue as many videos as you like — mixed formats are fine — and Video Mender converts or compresses all of them locally, with real per-file progress and a scheduler that will not exhaust your device memory.