Supported Video Formats
JustTrimVideo uses FFmpeg under the hood, which means it can handle virtually any video format you throw at it. Your video is processed locally in your browser - no upload required, no matter the format.
How Format Support Works
Our tool uses "stream copy" mode, which means it extracts the portion you want without re-encoding. This preserves original quality and works instantly regardless of the codec or container format.
All Supported Formats
MP4
Most common video format, universal compatibility
MOV
iPhone and Mac native format
MKV
Matroska container, popular for high-quality video
WebM
Web-optimized format, great for browsers
HEVC/H.265
Modern 4K codec, smaller file sizes
Frequently Asked Questions
What if my format isn't listed? ▼
If your browser can play the video, our tool can likely trim it. FFmpeg supports hundreds of formats and codecs. Just try it - there's no upload, so you'll know instantly if it works.
Will trimming change my video's format? ▼
No. We use stream copy mode, which keeps your video in its original format and codec. An MP4 stays an MP4, an MKV stays an MKV, etc.
Does format affect trimming speed? ▼
Not really. Since we're copying streams rather than re-encoding, trimming is nearly instant regardless of format. A 10-second clip from a 2-hour MKV takes the same time as from an MP4.
Ready to trim your video?
Go to the Video Trimmer →