Compress MP4 Online

Upload an MP4 and shrink its size in the browser using quality (CRF) or resolution presets. Plotlake outputs H.264 MP4 with AAC audio and faststart enabled for instant playback, no watermark, and no signup.

Quality modes map to Light/Medium/Heavy so you can pick balanced, smaller, or smallest files. Resolution options (Keep/1080p/720p/480p) maintain aspect ratio with even dimensions for maximum compatibility.

Because everything runs locally with WebAssembly FFmpeg, videos never leave your device. The first load caches the ~30MB engine, keeping subsequent compressions quick—even on repeated runs.

For stability, aim for clips under ~60 seconds. If you see errors, drop to 720p/480p or switch to Heavy compression to reduce memory and bitrate demands.

Shrink MP4 file size fast

One-click Light/Medium/Heavy modes plus resolution targets make reliable reductions without guesswork.

Choose quality or resolution

CRF-based quality plus Keep/1080p/720p/480p scaling preserves aspect ratio and ensures even dimensions.

Free to use, no sign-up required

No account, no watermark—export clean MP4 files ready for sharing.

Privacy-first processing

Compression runs locally in your browser; nothing uploads to a server.

Clear limits (no surprises)

Best results for clips under ~60s. Lower resolution or pick Heavy if memory or time is tight.

Key benefits

Frequently Asked Questions

Is it free?

Yes. Free to use with no watermark or signup.

Do you add a watermark?

No branding or watermark is added to your MP4.

Do you upload my video?

No. Compression runs locally in your browser using WebAssembly FFmpeg.

Why does quality drop?

Heavier CRF values trade detail for size. Use Light or Keep resolution for higher quality.

Which preset should I use?

Light for balance, Medium for smaller files, Heavy for the smallest size. Combine with 720p/480p if needed.

What are the limits?

Best under ~60 seconds for stability. Large files may need lower resolutions to avoid memory issues.

Why is it slow?

First run downloads FFmpeg (~30MB). High resolutions and longer clips take more time to encode in-browser.

Why did compression fail?

Try Heavy + 720p/480p, or shorten the clip before uploading to reduce memory and CPU load.

How to get smaller files?

Pick Heavy, drop to 720p/480p, and avoid very high-bitrate sources when possible.

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