Guide · 2 min read · Updated 15 October 2026
How to convert iPhone videos to MP4 and make them small enough to send
You send a video from your iPhone and the other person gets a file that will not play, plays without picture, or is far too big to attach. All three problems have the same roots: the format the iPhone records in and the very high quality it records at. This guide explains both and fixes them in a few minutes, without uploading your videos anywhere.
Why iPhone videos cause trouble
- The container: iPhone videos are saved as .MOV. Most devices open MOV, but some upload forms only accept .MP4.
- The codec: since 2017 iPhones record in HEVC (H.265) by default. It halves the file size, but some Windows PCs, older TVs, browsers and editing apps cannot decode it, so they show an error, a black picture or sound only.
- The size: a minute of 4K video from an iPhone can be well over 100 MB, more than email and many forms accept.
Step 1: convert to MP4
Open MOV to MP4 and add the videos.
- Fast checks each video. If it is already H.264, it is just moved into an MP4 file in seconds, with no change in quality. HEVC videos are re-encoded to H.264.
- Maximum compatibility re-encodes everything to H.264. Choose it when a video must play on an old computer or TV, or a strict website.
The result is an H.264 MP4 with AAC sound, which plays on practically every phone, computer, TV and website.
MOV → MP4MOV to MP4Convert MOV, MKV, AVI, WebM and 3GP videos to MP4 in your browser. Lossless when possible, H.264 for full compatibility. Free, private, no sign-up.Step 2: make it smaller
Start by cutting what you do not need with Trim video: Fast mode takes seconds and keeps full quality. Then, if the file is still too big, use Compress video:
| Sending it by… | Resolution | Quality |
|---|---|---|
| email (often 20–25 MB limit) | 720p or 480p | Balanced or Smallest |
| WhatsApp, Telegram | 720p | Balanced |
| upload form or website | 1080p | High or Balanced |
At 720p, phone videos usually shrink by 70–90% while still looking good on a phone or laptop.
Other fixes
- Plays sideways on some players? Turn it for real with Rotate video.
- Need only the sound, such as a recorded lecture? Use Extract audio.
- Want a short loop for a chat? Make a GIF with Video to GIF.
Stop the problem at the source
On the iPhone, go to Settings → Camera → Formats and choose Most Compatible. New videos are then recorded in H.264 and photos in JPG, which every device opens. The files are larger, so this suits people who often send videos to Windows users or upload them to websites. Settings → Camera → Record Video lets you lower the resolution (1080p instead of 4K) to keep files smaller from the start.
Frequently asked questions
Does converting MOV to MP4 lose quality?
Not when the video is already H.264: it is copied as it is. Re-encoding HEVC to H.264 uses high-quality settings that look the same in practice.
Why does the video play on my iPhone but not on the computer?
The computer cannot decode HEVC (H.265). Converting to H.264 MP4 fixes it.
How long does it take?
Copying is a matter of seconds. Re-encoding runs on your computer’s processor in the browser and takes roughly as long as the video itself on a laptop.
Are my videos uploaded?
No. Everything runs in your browser with ffmpeg compiled to WebAssembly.