How it works
- Drop your videos.
- Choose the format and any resize, crop or rotate options.
- Download the converted videos.
Why use it
- MP4, WebM, MOV and MKV output.
- Resolution, frame rate, crop and rotate.
- Quality levels from small to very high.
- Private, with no size limit.
Converting video: containers, codecs and what to choose
Container and codec
A video file is a container holding separate streams of picture and sound, each compressed with a codec. The file extension names the container: MP4, MOV, MKV, WebM. Whether a video plays somewhere depends mostly on the codecs inside. That is why a MOV from an iPhone can refuse to play on an older Windows computer while an MP4 from a camera plays everywhere.
| Output | Codecs written | Plays on |
|---|---|---|
| MP4 | H.264 picture, AAC sound | Everything: phones, computers, TVs, browsers, social networks |
| MOV | H.264 picture, AAC sound | Apple software, and most players |
| MKV | H.264 picture, AAC sound | VLC and desktop players; not all phones or browsers |
| WebM | VP9 picture, Opus sound | Every current browser; fewer apps and TVs |
For sending, sharing and uploading, MP4 is the answer almost every time. WebM suits video on your own website: in our tests it was about a quarter smaller than MP4 at the same quality setting. Every conversion encodes the picture again, so a little detail is lost each time; convert from the original rather than from a converted copy.
Quality and size
The quality setting decides the bitrate, and with it the size. On a 10 second full HD camera clip, our measurements were 2.4 MB at Small files, 4.3 MB at Balanced, 7.6 MB at High, the default here, and 14.7 MB at Very high, in MP4. High keeps footage close to the original for further editing or keeping; for a file that has to fit a limit, compress video works out the bitrate from the size you need.
Changing the picture on the way
- Resolution scales the video down, from 4K to 1080p or 720p for example. It never scales up.
- Frame rate drops to 30, 24 or 15 frames per second. Useful for screen recordings at 60 that do not need it.
- Crop to shape cuts the centre of the picture to 16:9, 9:16 vertical, 1:1 square or 4:5, to turn a landscape video into a vertical one for Stories and Reels.
- Rotate fixes videos filmed sideways, in quarter turns; Mirror flips selfie videos.
Speed and hardware
Encoding uses the video encoder built into your computer's graphics chip or your phone, through the browser's WebCodecs interface, so nothing is uploaded and there is no size limit beyond your device's memory. Speed depends on that hardware: our 10 second full HD clip took about 17 seconds on a desktop computer. Keep the tab open until the conversion finishes.
If something goes wrong
- It says the browser cannot decode the video. Some videos, such as HEVC from recent iPhones, need hardware support that not every browser has. Try Edge, Chrome or Safari on a recent computer.
- The result is larger than the original. The original was already compressed more than High allows. Choose Balanced or Small files, or keep the original.
- The browser says it cannot do this. The converter needs WebCodecs, which Chrome, Edge, Safari 16.4 or newer and Firefox 130 or newer provide.
How we tested. Sizes and times from our video compression tests: a 10 second clip at 1920 by 1080 and 30 fps, encoded with this site's video engine in Chrome on a desktop computer with H.264 in hardware.
Popular ways to use this tool
Questions and answers
How do I convert MOV to MP4?
Drop the MOV file, keep MP4 selected and click Convert.
Can I make a vertical video from a horizontal one?
Use Crop to shape and pick 9:16 or 1:1. The center of the picture is kept.
Which formats can it read?
Any video your browser can decode, typically MP4, MOV, WebM and MKV.
Related guides
GIF vs MP4 vs WebM: the same clip in each format
We turned a camera clip and a screen recording into a GIF, an MP4 and a WebM at the same size. The GIF was up to 16 times larger and still looked worse. Here is why, and when a GIF is still the right choice.
How to compress a video: what each setting really does
A video's size is its bitrate times its length, and every setting works through that. We compressed two full HD clips at every setting and measured the size and quality of each result, including the usual advice to lower the resolution.
Do online converters upload your files?
Most online converters send your file to a server; some do the work in your browser instead. Here is how to tell which kind a site is in about a minute, and what every request looked like when we converted a photo on our own site.