Convert video format
Convert between MP4, WebM, MKV and MOV; MP4 and MOV get H.264 video and AAC sound so any player opens them, and other formats copy streams when they can. Scale down, remove the sound or trim at the same time. Encoding uses the browser.
Process locally
Files stay in this browser session. Closing or clearing releases them.
Choose files
MP4, MOV, WebM, MKV, up to 5
Drop files here, or
Adjust settings
Optional: Output format, Largest height, Sound and more
Run
Processes in this browser; cancel at any time
About this tool
Convert videos between MP4, WebM, MKV and MOV, for example to turn a WebM screen recording into an MP4 for sharing, to make a lower-resolution copy that takes less space, or to remove the sound from a clip.
MP4 and MOV get H.264 video and AAC sound when your browser can encode them, while WebM and MKV keep the original streams when the format allows. You can also scale the video down and cut a time range. Up to 5 videos, 80 MB in total, are converted in your browser and are not uploaded.
How to use it
- Choose up to 5 MP4, MOV, MKV or WebM videos, or drop them on the page.
- Pick the “Output format” and, for a smaller video, a “Largest height” such as 720p.
- Set “Sound” to “Remove” for a silent video. To keep only part of it, fill in “Start” and “End” in seconds or m:ss.
- Select Run, then preview and download the results.
Formats and limits
- Input
- MP4, MOV, WebM, MKV, up to 5 files
- Output
- MP4, WebM, MKV, MOV
- Size limit
- 80 MB per file
- Settings
- Output format (MP4, WebM, MKV, MOV); Largest height (360p, 480p, 720p, 1080p, 2160p, Keep); Sound (Keep, Remove); Start; End
- Privacy
- Files stay in the current browser session. No file bytes are uploaded.
- Price
- Free, no sign-up
Common questions
Why is one conversion quick and another slow?
When the new format accepts the original video and sound, they are copied, which is fast and keeps the quality. Changing the codec, for example from an H.264 MP4 to WebM, or scaling down means your browser decodes and re-encodes every frame, which takes much longer.
Will choosing 720p enlarge a smaller video?
No. “Largest height” only scales down videos that are taller than it, and the width follows the original aspect ratio.
Why does a long video fail partway?
Each run may take at most 2 minutes. If re-encoding takes longer, convert a shorter part with “Start” and “End”, pick a format that can copy the streams, or convert one video at a time.
Is an MP4 result always H.264?
Only if your browser can encode H.264 at that size; likewise the sound becomes AAC only if the browser can encode AAC. Otherwise the original streams are kept, and some players may not open the file.
How do I save just the sound?
Use “Extract audio from video” to save the sound track as its own audio file.
Related tools
Extract audio from video (MP4 to MP3)
Take the sound out of MP4, MOV, MKV or WebM video and convert it to MP3, M4A, OGG, WebM or WAV, or keep the track unchanged in its own container, optionally trimmed. Files are not uploaded.
Trim audio
Cut a time range out of MP3, WAV, M4A, AAC, OGG, FLAC or WebM audio without re-encoding, so quality is unchanged.
Convert audio to MP3, M4A, OGG or WAV
Convert MP3, WAV, M4A, AAC, OGG, FLAC and WebM audio to MP3, M4A, OGG, WebM or WAV, with bitrate, sample rate and channels. MP3 is encoded with LAME and the other formats by the browser; files are not uploaded.
Change audio volume
Make audio louder or quieter by a percentage, clipping at full scale, and save it as MP3, M4A, OGG, WebM or WAV.
Screen recorder
Record a screen, window or tab with its sound and your microphone if you like, and save MP4 or WebM.
Convert font format
Convert fonts between TTF/OTF, WOFF and WOFF2 without changing any glyph. Outlines stay as they are, so a TrueType font stays TTF and a CFF font stays OTF.