Free tool

MOV to MP4 Converter

Most MOV files already contain video and sound that MP4 supports, so converting them doesn't need re-encoding at all. This tool copies the streams into an MP4, which takes seconds even for a long clip, keeps the picture exactly as it was, and happens on your own device.

01 — Your file

Choose a file

02 — Result

Your converted file

Choose a file and press Convert to MP4. The conversion runs in this tab, so even large files never leave your computer or phone.

Converting MOV to MP4

  1. Choose the MOV above. The file card shows the picture codec, usually H.264 or H.265 (HEVC).
  2. Press "Convert to MP4".
  3. Download the MP4. The result card says whether the picture was copied or re-encoded.

Why it is usually instant

MOV (Apple's QuickTime format) and MP4 are close relatives: both are containers built on the same structure. An iPhone, a Mac screen recording or most cameras put H.264 or HEVC video and AAC sound inside, and MP4 accepts all three. So the converter rewraps the existing streams instead of decoding and compressing them again. In our tests a 20-second iPhone clip converted in a fraction of a second, and length barely matters because nothing is being processed frame by frame.

The output also gets the "fast start" layout, which puts the file's index at the front so web players can begin playing before the whole file has loaded.

iPhone HEVC videos

iPhones set to "High Efficiency" record HEVC. The converter copies HEVC as it is and tags it the way Apple's players expect, so the MP4 plays in QuickTime, Photos and Safari. Some older Windows PCs and TVs can't decode HEVC at all, in any container; for those, set the iPhone camera to "Most Compatible" for future recordings. The HEVC compatibility article explains where HEVC plays and where it doesn't.

When re-encoding happens

Professional MOV files from editors and cinema cameras often use ProRes, which MP4 players don't support. Those are re-encoded to H.264, and the result card says so. Re-encoding is far slower than copying, especially in a browser and for HD footage, so for long ProRes masters a desktop tool such as HandBrake is the faster route. If the sound is uncompressed PCM, it is converted to AAC, which is small and plays everywhere.

Do it by hand

For the ffmpeg command, and for converting other formats on your own computer, see the guide to converting MOV to MP4 without losing quality. The MP4 vs MOV comparison covers which container to choose in the first place.

Translate or transcribe it next

mydubly accepts MOV directly, so you don't need to convert to translate a video: the video translator and MOV to text pages take the original file.

How the free converter works

The converter is ffmpeg, the open-source media toolkit, compiled to WebAssembly so it runs inside your browser tab. Your file is read straight from your disk by that engine; it is never uploaded to mydubly or anywhere else, and no account is needed.

  • The engine is about 30 MB and downloads the first time you convert something. After that your browser normally keeps it.
  • Large inputs are fine because the file is read in place, but the result is built in memory, so outputs are capped at about 1.5 GB.
  • Speed depends on your device. Copying streams takes seconds; re-encoding video is the slow case.
  • Keep the tab open until the download button appears. Closing it stops the conversion.

More free tools

Turn the file into text

Frequently asked questions

Does converting MOV to MP4 reduce quality?

Not for H.264 or HEVC MOV files, which is nearly all phone and camera footage: the picture and sound are copied without re-encoding. Only formats MP4 can't hold, such as ProRes, are re-encoded.

Can I just rename .mov to .mp4?

Sometimes it plays, but it isn't a real conversion and some apps reject it. Rewrapping properly takes seconds here.

Will the MP4 play on Windows?

H.264 MP4s play everywhere. HEVC MP4s need HEVC support on the PC, which some Windows machines lack.

Is there a size limit for MOV files?

The MOV itself can be very large, since it is read in place. The MP4 is built in memory, so outputs above about 1.5 GB are refused.