toolkit Pick as many .mov files as you like above and they become .mp4 right here, in this browser tab. Nothing is uploaded, which matters more for video than for photos: a 4 GB clip would take far longer to reach a server than to convert, and here it never goes. Packets are copied rather than re-encoded, so the conversion is near-instant and lossless — and if the video still will not play afterwards, the section below explains why that is the codec and not the container.
This does not re-encode your video
A .mov and an .mp4 are both containers — boxes that hold an already-compressed video stream and an audio stream. In the overwhelming majority of cases the streams inside a .mov are already exactly what an .mp4 is supposed to contain, so converting between them means rewriting the box and copying the contents across untouched. No frame is decoded, nothing is re-compressed, and the result is bit-for-bit the same video and audio you started with. That is why it is instant, and why there is no quality setting on this page: there is no quality decision to make.
A folder of clips, in one pass
Because this is a container rewrite rather than a re-encode, batching is where it pays off most: the packets are copied across untouched, so ten clips take roughly ten times almost nothing. Add them all at once, watch each report its own progress, and save the finished set as a single .zip. There is no upload, so file size never decides whether a batch is practical — a hundred gigabytes of video would have been a non-starter on any converter that had to receive it first.
Why an iPhone video is a .mov at all
iPhones record to QuickTime (.mov), Apple's own container. It is a close relative of MP4 — they share a common ancestor — but plenty of upload forms, editors and older players check the file extension and reject .mov out of hand, even though they could read the contents perfectly well. That is the exact problem this page fixes: same video, a container that everything accepts.
If your video still will not play, it is the codec, not the container
Worth being straight about, because most converters are not. Since iOS 11, iPhones record video as HEVC (H.265) by default under the High Efficiency setting. HEVC plays perfectly on Apple devices, but many Windows installations have no HEVC decoder and will refuse it — and changing the container from .mov to .mp4 does not change that, because the video inside is still HEVC. If your file plays here in the preview but not on the machine you are sending it to, that is what is happening, and the fix is re-encoding to H.264 rather than converting the container. This tool tells you when your file is in that situation instead of pretending the job is done.
Your video does not leave the browser
There is no upload, and there is no server-side conversion — this site has no endpoint that accepts a file at all. The container is rewritten by JavaScript running in this tab, reading the file straight off your disk. You can check that claim rather than take it on faith: open your browser's network tab and convert something, or read the Content-Security-Policy this page is served with, which forbids the page from sending data anywhere but back to this origin.
Frequently asked questions
Does converting MOV to MP4 reduce the quality?
No. The video and audio are copied across without being decoded or re-compressed, so the result is identical to the source. Converters that re-encode do lose quality; this one has nothing to lose because it never touches the compressed data.
Can I convert several MOV files at once?
Yes, as many as you like. They are queued and rewritten one after another — usually a fraction of a second each, since nothing is re-encoded — and the finished MP4s are offered as one .zip. There is no count or size limit and no charge.
How large a file can I convert?
Files of a gigabyte have been tested successfully. The practical limit is your device's available memory rather than any restriction here, and there is no file-size cap, no queue and no account.
Why is it so much faster than other converters?
Because it is not doing the same work. Most online converters upload your file, re-encode it on a server and send it back, which takes as long as the upload plus the encode. This rewrites the container locally and copies the streams, which is roughly as fast as your disk can read the file.
Will the converted file play on Windows?
If the video inside is H.264, yes, everywhere. If it is HEVC (H.265) — which is what recent iPhones record by default — it will play on Apple devices but may not on Windows without an HEVC extension installed. The tool tells you which one you have after converting. To avoid it in future, set Settings > Camera > Formats to Most Compatible on the iPhone, which records H.264 instead.
Does this work with MKV, WebM or TS files too?
Yes, provided what is inside them is legal in an MP4 container — H.264, HEVC, VP9 or AV1 video with AAC, MP3, Opus or FLAC audio, which covers most files you will meet. Anything that cannot be stored in an MP4 is reported rather than silently dropped.
Is the audio kept?
Yes, and copied without re-encoding like the video. Any track that cannot legally live in an MP4 container is reported to you rather than quietly discarded.