Compress MP4 Video Online Free
Reduce the size of your MP4 files directly in your browser. No upload, no signup — just drop your file and choose your quality settings.
Powered by ffmpeg.wasm - runs entirely in your browser
Why MP4 compression matters
MP4 is the most common video format, but raw recordings can be huge. H.264 re-encoding can shrink a 500MB recording to under 100MB with barely visible quality loss.
How to Get Started
Key Features
No upload needed
Your MP4 is processed locally using ffmpeg.wasm. Nothing leaves your device.
Significant size reduction
Typical results: 60–80% file size reduction with 65% quality setting.
H.264 output
Output is always H.264 MP4 for universal compatibility across all devices.
Adjustable resolution
Optionally downscale to 720p or 480p for even smaller files.
Frequently Asked Questions
Can I compress an MP4 without losing quality?
At 80–90% quality setting, the quality loss is nearly imperceptible. At 65%, it's still very good for sharing. Going below 40% shows visible artifacts.
What is the maximum MP4 file size I can compress?
There's no hard limit. On a desktop, files up to 2GB work reliably. Very large files will take longer to process.
Does the output stay in MP4 format?
Yes. The output is always an MP4 file (H.264 video + AAC audio), regardless of the input format.
Why does compression take a few minutes?
Unlike stream-copy trimming, H.264 re-encoding involves real computation on every frame. In a browser, this takes 1–5 minutes depending on your device and file size.
Related
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