Are my files uploaded to a server?

No. This conversion runs inside your browser using your own device’s processing power, and the file is not uploaded. Once a tool has been used once (video, text recognition and background removal download their engine from this site the first time), it keeps working when your connection drops.

Not when the streams can be copied. If a re-encode is needed — for a clip filmed upright, or when you change the quality or resolution — the default settings keep the difference hard to see.

How large a video can I convert?

You are warned above 500 MB because encoding in a browser gets slow on a long file. Above 1 GB the video is converted in parts of a few minutes each and joined back into one file at the end — the file itself is read from disk as it goes, so a long recording works. Only a finished video too big to hold in memory is delivered as parts, each a complete file.

Convert MOV to MP4

Runs on your device · Your file never leaves your device.

MOV is what iPhones and QuickTime record, but many Windows programs, editors and upload forms prefer MP4. Converting keeps the video in the format they expect.

Where the picture inside is H.264 or HEVC, as iPhone recordings are, the streams are copied rather than re-encoded, which is fast and lossless. A clip stored on its side with a rotation note — the usual result of filming upright — is encoded again so that it stands upright in every player.

The conversion runs on your device, so a personal recording is never uploaded just to change its container. Large videos are limited by your device memory, so a phone handles short clips best.

How to convert MOV to MP4

Add the MOV file from your iPhone or QuickTime.
Press Convert — H.264 or HEVC footage without a rotation note is copied rather than re-encoded.
Download the MP4.

Supported formats and limits

Input: MOV (iPhone, QuickTime)
Output: MP4
Speed: Very fast when the streams can be copied
Quality: Unchanged in the copy case
Limits: Warned above 500 MB; converted in parts and rejoined above 1 GB
Where it runs: In your browser; nothing uploaded

Not for: A result bigger than the device can hold in one piece — it arrives in parts, each a complete MP4, which the Join mode puts back together.

iPhone recordings: copied or encoded

Recent iPhones record in HEVC unless the camera format is set to Most Compatible, which records H.264. Either picture is copied into the MP4 as it is, with the sound, when Quality and Resolution are left unchanged: nothing is decoded, and it takes seconds. A copied HEVC picture still needs a player that opens HEVC, and some Windows programs, older TVs and upload forms do not. For those, turn on Force re-encoding to get H.264.

When the picture is encoded, your device’s own encoder does it if the browser can decode HEVC on that device. Otherwise the slower built-in engine takes over, and the progress line then does not mention your device’s video encoder. The iPhone’s AAC sound is copied untouched on both.

Clips filmed upright

A clip filmed upright is usually stored on its side, with a note that tells players to turn it. Such a clip is not copied: it is encoded again with the turn written into its pixels and no note, so it stands upright even in programs that ignore the note. If the clip was filmed the wrong way round in the first place, turn it at /rotate-video.

Vertical videos and the Resolution setting

The Resolution choices set the shorter side of the picture as it is shown. A vertical 1080×1920 clip at 720p becomes 720×1280, and at 480p 480×854; a clip already smaller than the choice keeps its size. Any choice that changes the size means the picture is encoded again.

To meet a size limit for sending instead, /compress-video works out the bitrate and the frame size from the limit you type.

Frequently asked questions

Are my files uploaded to a server?: No. This conversion runs inside your browser using your own device’s processing power, and the file is not uploaded. Once a tool has been used once (video, text recognition and background removal download their engine from this site the first time), it keeps working when your connection drops.
Will I lose quality?: Not when the streams can be copied. If a re-encode is needed — for a clip filmed upright, or when you change the quality or resolution — the default settings keep the difference hard to see.
How large a video can I convert?: You are warned above 500 MB because encoding in a browser gets slow on a long file. Above 1 GB the video is converted in parts of a few minutes each and joined back into one file at the end — the file itself is read from disk as it goes, so a long recording works. Only a finished video too big to hold in memory is delivered as parts, each a complete file.