MotionShine01 / Drop
Drop one file or many
Drag MOV files in or click to pick them. Each one is read from your own disk.
Free tool
MOV to MKV converter.
Turn a QuickTime MOV, such as an iPhone video or a Mac screen recording, into an MKV. MKV can hold nearly any picture and sound, so the streams are copied across untouched and nothing is lost. It runs in your browser, so nothing is uploaded.
Reading the file...
This runs in your browser. Your files are never uploaded.
How it works
Three steps, nothing to install.
02 / Convert
It turns into MKV by itself
Each file becomes an MKV as soon as it is in. The line above the download button says what was copied and how big the MKV is.
03 / Save
Download one or all
Play the result, then download it, or get every file in one ZIP.
Guide
How to convert MOV to MKV, without re-encoding.
A MOV to MKV converter puts the picture and sound from a QuickTime file into a Matroska file. Matroska is an open container that accepts almost every codec, including H.264, HEVC, AAC, PCM and Apple ProRes in this tool. That makes this the easy direction: nothing has to be translated, so the streams are copied bit for bit and the MKV looks and sounds the same as the MOV.
How to use the MOV to MKV converter
- Drop one or more MOV files on the box, or click to choose them.
- Each file turns into an MKV by itself. Wait for the line that starts with "Ready".
- Read that line. It says "copied" for each stream that was not re-encoded.
- Press Download the MKV. With several files, use Download all as ZIP.
What happens to each stream
| Inside the MOV | In the MKV |
|---|---|
| H.264 or HEVC picture | Copied |
| ProRes or other picture | Copied |
| AAC, MP3 or PCM sound | Copied |
| A picture turned by a rotation flag (a phone held upright) | Re-encoded, turned upright |
The one case that re-encodes: phone video held upright
An iPhone saves an upright video sideways and adds a flag that tells the player to turn it. MKV has no such flag in this tool, so the picture is re-encoded already turned. It then plays upright everywhere. This costs a small amount of quality and takes longer than a copy. The result line says "re-encoded" when it happens. If you want to avoid that, keep the file as MOV or MP4.
Why people want MKV
- Media players such as VLC open it, and it can hold several sound tracks and subtitles in one file.
- An archive that mixes codecs from different sources can live in one container.
- A recording tool or a server asks for MKV by name.
MKV is not the right choice for Apple apps. QuickTime Player, iMovie and many phone apps prefer MOV or MP4, so keep the MOV if you edit on a Mac.
Check the result
Play the preview on the page. It can stay blank for a picture the browser cannot play, such as ProRes, even though the file was written correctly. Open that kind in VLC to check. The line above the download button is the record of what was copied.
Do you gain anything in file size?
No. A copy moves the same bytes into a new box, so the MKV comes out within a few percent of the MOV. A 1 GB MOV makes an MKV of about 1 GB. To make a file smaller, open Quality and Size: each option shows the size it would give, but that re-encodes the picture.
Common problems
- The MKV has no sound in a player. The player may not support the sound codec. PCM and AAC play almost everywhere; try VLC.
- A ProRes file is very large. ProRes is an editing codec, so the MKV is just as big. Most browsers cannot decode ProRes, so this page cannot make it smaller.
- A long recording fails. The file is held in memory. Close other tabs, or cut it with the video trimmer first.
Going the other way? MKV to MOV does that. For the common formats, use MOV to MP4.
Questions
Good to know.
Is my file uploaded?
No. The file is read and written in this tab by your browser, so it never leaves your computer.
Does MOV to MKV lose quality?
No for a normal copy. The picture and sound are written into the MKV as they are. The only re-encode is a picture that carried a rotation flag, such as an upright iPhone video, and the result line says so.
Why is the MKV the same size as the MOV?
Because the streams were copied. Only the container around them changed, and that is a tiny part of the file.
Can I just rename .mov to .mkv?
No. The two containers are laid out differently inside, so players and tools that check the file will refuse a renamed one.
Will the MKV open on a Mac?
QuickTime Player and many Apple apps prefer MOV or MP4. VLC and other media players open MKV. Keep the MOV for editing on a Mac.
Does it work with ProRes?
The picture is copied as it is, so a ProRes MOV becomes an MKV of the same size. This browser does not have to play ProRes for that to work, so the preview may stay blank.
Can I convert many files at once?
Yes. Drop as many as you like. They are made one after another with the same settings, and Download all as ZIP saves them together.
Is there a file size limit?
The file is handled in your browser memory, so very large files can fail. Close other tabs and try again, or cut the file into parts first.