To convert MOV to MP4, open the free MOV to MP4 converter, drop in your .mov file and click Convert; the MP4 downloads a few seconds later and nothing is uploaded. When the video inside the MOV already uses H.264, the tool only rewraps it, so the MP4 is a perfect copy with no quality loss.
This guide explains why MOV files cause trouble, what actually happens during the conversion, how iPhone videos differ, and how to stop getting MOV files in the first place.
What is the difference between MOV and MP4?
MOV and MP4 are both containers: boxes that hold a video stream, an audio stream and some metadata. MOV is Apple's QuickTime format; MP4 is the international standard (MPEG-4 Part 14) that was built on QuickTime's design, which is why the two are so similar.
The difference that matters is support. Almost every phone, TV, browser, editor and website plays MP4. MOV plays well on Apple devices but can fail on Windows players, Android phones, smart TVs, some web forms and some social apps.
| MOV | MP4 | |
|---|---|---|
| Made by | Apple (QuickTime) | ISO standard (MPEG-4) |
| Usual video codec | H.264 or HEVC (H.265) | H.264 (also HEVC, AV1) |
| Plays on Windows, Android, TVs | Sometimes | Almost always |
| Accepted by upload forms | Often rejected | Widely accepted |
| Quality | Same codec, same quality | Same codec, same quality |
The last row is the key point: a container does not decide quality. The codec and its bitrate do.
How to convert MOV to MP4 for free (step by step)
- Open the MOV to MP4 converter in Chrome, Edge, Firefox or Safari.
- Drag your .mov file onto the drop zone, or click to choose it. The tool reads it on your device and shows the duration, resolution and codecs.
- Read the line under the file. It tells you in advance whether the video will be copied (fast, lossless) or re-encoded.
- If it will be re-encoded, choose a quality level: High quality stays close to the original, Balanced gives a smaller file.
- Click Convert, then download the MP4. The result card shows the size before and after and how long it took.
There is no account, no watermark and no file size cap set by a server, because the file never leaves your computer. Very large videos are limited only by your device's memory.
Can you convert MOV to MP4 without losing quality?
Yes, whenever the MOV already holds H.264 video. In that case the converter copies the video packets into an MP4 container without decoding them. This is called remuxing. It takes seconds even for long clips and the picture is bit for bit identical.
Audio works the same way. AAC or MP3 audio is copied as is. Other audio formats, such as the PCM audio some cameras record, are converted to AAC at 160 kbps (High quality) or 128 kbps (Balanced), which is transparent for speech and most music.
Re-encoding is only needed when the video codec cannot live in a widely playable MP4. The tool then re-encodes to H.264 with your browser's hardware encoder. Any re-encode is lossy in principle, which is why High quality is the default.
Why iPhone MOV videos need re-encoding
Since iOS 11, iPhones record in HEVC (H.265) by default to save space. HEVC inside a MOV plays fine on Apple devices but is the main reason a video "won't open" on Windows, older Android phones or a website.
When you drop an iPhone MOV into the converter, it will usually say the HEVC video is re-encoded to H.264. That is correct and expected: H.264 is the codec that plays everywhere. Expect the MP4 to be somewhat larger than the HEVC original at the same visual quality, because HEVC compresses more efficiently.
Two tips for iPhone videos:
- HDR clips (Dolby Vision, the default on recent iPhones) can look slightly flatter after conversion on non HDR screens. That is a display difference, not a fault in the file.
- Long 4K clips take longer to re-encode. Close other heavy tabs and keep the laptop plugged in for the fastest result.
How to stop your iPhone from recording MOV in HEVC
If you share videos with Windows or Android users often, change the camera format once and skip the conversion:
- Open Settings and tap Camera.
- Tap Formats.
- Choose Most Compatible.
New videos are then recorded in H.264. They still use the .mov extension, but they convert to MP4 instantly and losslessly, and most players open them anyway. The trade off is larger files: H.264 needs more space than HEVC for the same quality. Apple documents this setting in its guide to HEIF and HEVC media.
Converting MOV to MP4 on Windows and Mac
A browser converter works the same on every system, which is the easiest route on a work computer where you cannot install software.
- Windows: the Photos app and Media Player may refuse HEVC MOV files unless the paid HEVC extension is installed. Converting to H.264 MP4 removes that need.
- Mac: QuickTime plays MOV natively, so most Mac users only need MP4 when sending a video to someone else or uploading it to a form or website.
- Chromebook and Linux: the browser route is usually the simplest option, since few desktop converters target these systems.
Common MOV to MP4 problems and fixes
| Problem | Cause | Fix |
|---|---|---|
| "This browser cannot encode H.264" | Your browser lacks an H.264 encoder | Use the latest Chrome or Edge |
| MP4 has no sound | The audio codec could not be converted in this browser | The tool tells you; try Chrome or Edge, or extract the audio separately |
| MP4 is bigger than the MOV | HEVC was re-encoded to H.264 | Choose Balanced, or run the MP4 through the video compressor |
| Conversion is slow | A long 4K HEVC clip is being re-encoded | Plug in the laptop and close other tabs |
Related tools
Need only the sound from a clip? Use extract audio from video to save it as MP3, M4A or WAV. Sending the video by email or chat? Shrink it afterwards with the video compressor.
Ready to convert? Open the free MOV to MP4 converter and drop your file in. It stays on your device from start to finish.
Frequently asked questions
Is converting MOV to MP4 lossless?
It is lossless when the MOV holds H.264 video, because the converter copies the video into the MP4 without re-encoding it. iPhone videos recorded in HEVC must be re-encoded to H.264, which is lossy in principle, so use the High quality setting for those.
Why won't my iPhone MOV video play on Windows?
Recent iPhones record in HEVC (H.265), which Windows only plays with an extra codec extension. Converting the video to an H.264 MP4 makes it play in Windows Media Player, Photos and almost every other app.
Is it safe to convert MOV to MP4 online?
With WoowTools the conversion happens inside your browser, so the video is never uploaded to a server. That makes it a good choice for private family clips and work recordings.
Is there a file size limit?
There is no server limit, because nothing is uploaded. Very long or 4K videos are limited only by your device's memory and take longer to re-encode.
Can I just rename .mov to .mp4?
Renaming sometimes works for H.264 files because the formats are similar, but it is unreliable and fails for HEVC videos. A proper remux rewrites the container correctly and takes only seconds.
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