How to Convert an iPhone MOV Video to MP4 Without Losing Quality
You AirDrop an iPhone video to your Windows laptop, drop it into an editor or upload form, and get "unsupported format". It's a .mov. The video inside is almost always perfectly standard; it's the wrapper that bothers some software. MOV to MP4 rewraps it as an MP4, and in most cases it doesn't touch the actual picture at all.
Copying vs re-encoding
A video file has two layers: the container (MOV, MP4, MKV) and the codecs inside it (H.264 or HEVC for video, AAC or MP3 for audio). Lots of "MOV problems" are really container problems.
When the codecs inside are ones MP4 supports (H.264 and HEVC video, AAC and MP3 audio) the page copies them into a new MP4. Nothing is decoded or compressed again. Quality is identical, and even a long clip finishes in seconds. Because nothing is decoded, this even works in browsers that can't play HEVC themselves.
When the codecs are less portable (ProRes, animation codecs, uncompressed PCM audio) the page re-encodes them with the browser's video encoder into something widely playable, usually H.264 with AAC.
Before you convert, it tells you which will happen for the video and the sound.
Steps
- Open the .mov file (or another video you want as MP4).
- Read whether the video and audio will be copied or re-encoded.
- Press Convert to MP4 and download.
HEVC and the H.264 checkbox
Recent iPhones record in HEVC (H.265) by default to save space. Copying HEVC into MP4 keeps quality, but some older TVs, Windows machines without the HEVC extension, and some web uploaders can't play HEVC. If that's your situation, tick the box asking for H.264. The page then re-encodes the HEVC video, which takes longer and needs a browser with a video encoder, but the result plays nearly everywhere.
Rotation
Phones store rotation as a flag rather than rotating the pixels. A copied file keeps that flag, so it plays the right way up in normal players. A re-encoded file is written upright, so even players that ignore the flag show it correctly.
Example: sending a clip to a Windows user
A colleague can't open the .mov you sent. Convert it here: the page will typically show "video: copy, audio: copy". A few seconds later you have an MP4 of the same size and quality. If they still can't play it, convert again with the H.264 box ticked. That second version solves nearly every compatibility complaint.
Browser support
Copying works wherever the page can read the file, including browsers without a video encoder. Re-encoding needs Chrome, Edge or Safari (computer or phone), or Firefox on a computer.
Tips
- If you're also trying to make the file smaller, use Video compressor instead; it outputs MP4 too.
- To change iPhone defaults going forward, Settings → Camera → Formats → Most Compatible records H.264 instead of HEVC.
- Need just the audio? Video to MP3.
Why the MOV/MP4 split exists
MOV is Apple's QuickTime container; MP4 is the international standard derived from it. They're close cousins, which is why copying between them is so painless, but plenty of Windows software, web uploaders and smart TVs only look for the .mp4 label.
Privacy
The tool page says everything runs in the page, and the MP4 is saved on your device when you press Download. Google ads appear on the page, as across the site.
FAQ
Will an iPhone video keep its quality? Yes. H.264 or HEVC with AAC is copied as is.
When does it re-encode? For ProRes, animation codecs and uncompressed audio, or when you ask for H.264 from HEVC.
Is rotation kept? Yes.
Why is it so fast? Because in the common case it isn't re-encoding anything.
Stuck with a .mov that won't open? MOV to MP4 usually fixes it in seconds.
— Alok Kumar Singh