Compress Video
Compress Video is a free online video converter for changing MP4, WEBM, MKV, MOV, and AVI files into MP4 files. Compress Video accepts 6 MIME types, returns video/mp4, includes 1 setting, and runs in your browser on the device.
Drop .mp4 / .webm / .mkv / .mov / .avi file here
or click to choose
Options
Key facts
- Input
- 5 formats: MP4, WEBM, MKV, MOV, and AVI (video/mp4, video/webm, video/x-matroska, video/quicktime, video/x-msvideo, video/avi)
- Output
- MP4 (video/mp4)
- Runtime
- your browser on the device
- Settings
- 1 control: Quality preset
- File mode
- 1 input file creates 1 output file
- Cost
- $0, no account required
How to use Compress Video
- 1
Open your MP4, WEBM, MKV, MOV, AVI file
Drop your MP4, WEBM, MKV, MOV, AVI file onto the page, or click to browse and pick one from your device.
- 2
Choose options
Adjust the conversion options to suit your needs. Defaults work well for most inputs.
- 3
Convert and download
Click Convert. Your MP4 file is ready to download in seconds.
Compress Video details
First, Compress Video reads MP4, WEBM, MKV, MOV, and AVI source files and prepares MP4 output for the video workflow. Next, The visible controls are Quality preset. Additionally, Files and text stay in the browser session.
Reduce a video's file size by re-encoding it as MP4 (H.264 video + AAC audio). Pick a CRF; Constant Rate Factor; preset that trades quality for size: 18 is visually lossless, 23 is a balanced default, 28 is heavy compression, and 32 produces the smallest files at noticeable quality cost. Sources taller than 1080p are downscaled to 1080p so browser ffmpeg.wasm doesn't blow its ~2 GB memory budget mid-encode. Encoding is real-time-ish on modern CPUs; a 5-minute 720p clip typically takes 1;3 minutes. The conversion runs entirely in your browser; the file never leaves your device.
Common searches
- video compress
- compress video
- shrink video
- reduce video file size
- video compressor
- compress mp4
Related tools
Tools that work with the same formats — most users open one of these next.
Video Trimmer
Cut a clip from a video file — MP4, WEBM, MKV, MOV, AVI — in your browser.
MP4 to WebM
Convert MP4 video to WebM (VP9 + Opus) — free, runs entirely in your browser.
MP4 to GIF
Convert MP4 video to an animated GIF — free online, with a tuned palette.
MP4 to MP3
Extract the audio track from an MP4 video as an MP3 file — free online.
MP4 to WAV
Extract the audio track from an MP4 video as an uncompressed WAV file.
MP4 to FLAC
Extract the audio track from an MP4 video as a FLAC file — free online.
Frequently asked
What is Compress Video?
Compress Video is a free online video converter for changing MP4, WEBM, MKV, MOV, and AVI files into MP4 files. Compress Video accepts 6 MIME types, returns video/mp4, includes 1 setting, and runs in your browser on the device.
What files does Compress Video accept and create?
Compress Video accepts MP4, WEBM, MKV, MOV, AVI files (video/mp4, video/webm, video/x-matroska, video/quicktime, video/x-msvideo, video/avi) and creates MP4 files (video/mp4). The page includes 1 setting: Quality preset.
Do my files and data stay private?
Yes. Compress Video runs entirely in your browser using your device's CPU. Files and text are never uploaded to our servers, so your data stays private.
How do I use Compress Video?
Open Compress Video, drop in your MP4, WEBM, MKV, MOV, AVI file, choose any options, and click Convert. Your browser does the work locally and produces a MP4 file you can save right away.
What is the maximum file size for Compress Video?
Because Compress Video runs in your browser, the maximum size depends on your device's available memory. Most modern phones and laptops handle files up to a few hundred MB without issues.