Reviewed 2026-10-20 by the Spool editorial team · How we test
Why most MOV to MP4 conversions take seconds
Convert and edit files on your device. The browser edition accepts up to 100 MB total, media up to 10 minutes and video up to 4K. Codec availability and device memory can limit individual jobs.
You'll see Remuxing (no quality loss) in the progress bar when this happens. If the file can't be copied (for example ProRes footage), the progress bar says Encoding video and we encode to H.264.
| What's inside your MOV | What we do | Speed |
|---|---|---|
| H.264 + AAC (iPhone "Most Compatible", most cameras, Mac screen recordings) | Copy both streams | Seconds |
| HEVC + AAC (iPhone "High Efficiency", default since iOS 11) | Copy both streams, tagged so Apple devices recognise it | Seconds |
| H.264/HEVC + PCM audio (some cameras and audio recorders) | Copy video, encode audio to AAC | Fast |
| Apple ProRes (Final Cut, high-end cameras) | Encode video to H.264 | Real encode; several minutes for long clips |
| Motion JPEG (old digital cameras) | Encode video to H.264 | Real encode, and a much smaller file |
The HEVC question: will my MP4 play on Windows?
A remuxed iPhone video is still HEVC inside, just in an MP4 container. It plays on iPhone, iPad, Mac, Android, most smart TVs, and in Chrome, Edge and Safari on systems with hardware HEVC support. Windows' built-in apps need Microsoft's HEVC Video Extensions from the Microsoft Store, and some older editors and upload forms reject HEVC entirely.
If you need maximum compatibility, set Quality to High, or pick a resolution. Either one makes us encode the video to H.264 (High uses CRF 20, a visually transparent setting), and the resulting MP4 plays everywhere. The file is usually somewhat larger than the HEVC original, because H.264 needs more bits for the same quality.
How to stop your iPhone from making MOV files
Go to Settings → Camera → Formats and choose Most Compatible. New videos are then recorded as H.264 and photos as JPG. The files still use the .mov extension when you AirDrop them, but they'll remux to MP4 instantly. Also check Settings → Photos → Transfer to Mac or PC: with Automatic selected, the iPhone converts files when you import them over a cable.
HDR and Cinematic videos
Recent iPhones record HDR (Dolby Vision) in 10-bit HEVC by default. When we remux, the HDR video stream is copied as it is. If you choose High or Smaller, or change the resolution, the result is standard 8-bit H.264. We don't tone-map HDR to SDR, so colours can look flat or washed out. For HDR clips, keep the default Balanced setting so the video is copied, or turn off HDR under Settings → Camera → Record Video before filming.
Some Apple-specific features have no equivalent in MP4: Cinematic mode depth data and the link between a Live Photo and its still image are not kept.
Mac and Windows alternatives
On a Mac, QuickTime Player's File → Export As re-encodes rather than remuxing, so it's slower and loses a little quality. On Windows, the Photos/Clipchamp editors also re-encode. If your MOV is H.264 or HEVC, this page is usually the fastest way to get an MP4 without any loss. For the full background, read MP4 vs MOV.
Troubleshooting
| Problem | Fix |
|---|---|
| MP4 plays sound but no picture on Windows | It's HEVC. Install HEVC Video Extensions, play it in VLC, or convert again with Quality: High to get H.264. |
| Video is sideways in some players | Phones store rotation as a flag. Most players honour it; for the rest, use Rotate video to fix the pixels. |
| Upload site still rejects the file | Many sites want H.264 and a maximum size. Convert with Quality: High, then compress if needed. |
| Colours look washed out | HDR footage was re-encoded. Convert with Balanced to keep the original HDR stream. |