Video Compressor

Shrink large videos for email, uploads, messaging, or storage. Choose a target size or quality level, downscale when needed, and understand the tradeoff before exporting.

Drag & Drop Your Video

or click to browse — any video format

Output Format
Quality (CRF)
Trim (optional)

Compression is about choosing what matters most: file size, visual quality, resolution, or speed. A 4K phone recording may be too large for email, a screen recording may need to fit into a help desk ticket, and a social clip may need to upload faster on a weak connection. This tool is built for those practical file-size problems rather than format conversion alone.

The compressor re-encodes video in your browser with adjustable quality and optional resolution scaling. Use a target size when you must fit under a limit such as 25 MB or 100 MB. Use the quality slider when you care more about visual control than an exact number. Downscaling from 4K to 1080p or 720p often saves more space than lowering quality too aggressively.

Expect real tradeoffs: high motion, grain, screen text, and low-light footage need more bitrate to look clean. Talking-head videos, slides, and static shots compress much better. If the output looks soft, raise the quality or keep a higher resolution. For very large originals, desktop browsers handle memory and CPU load more reliably than phones.

Why Use Our Video Compressor

Target File Size Mode

Need your video under 25 MB for email? Under 100 MB for a web upload? Set your target size in MB and the tool optimizes encoding to hit that goal while preserving maximum quality.

Quality Slider Control

Prefer manual control? Use the quality slider from 1 to 100. Higher values preserve more detail but produce larger files. Lower values create tiny files ideal for previews and thumbnails.

100% Private & Local

Your videos never leave your device — no upload to cloud servers, no privacy risks, no data collection. WebAssembly compresses everything right in your browser.

Resolution Scaling

Combine compression with resolution reduction for even greater size savings. Scale 4K down to 1080p, or 1080p down to 720p. Dramatic size reductions with minimal quality impact.

All Major Formats

Compress MP4, MOV, AVI, MKV, WebM, and virtually any video format. Output is always optimized H.264 MP4 for maximum compatibility.

No Limits, No Queue

Compress as many videos as you want with no daily caps, no watermarks, no registration — Start immediately. No waiting for other users to finish.

Features

  • Compress any video format (MP4, MOV, AVI, MKV, WebM, and more) with intelligent CRF-based encoding that balances file size against visual quality
  • Target file size mode. Specify your desired output size in MB and the tool automatically adjusts encoding parameters to hit that target
  • Manual quality slider from 1 to 100. Higher values preserve more detail (larger files), lower values create compact files for sharing and previews
  • Optional resolution scaling. Reduce 4K to 1080p or 1080p to 720p for dramatic file size reductions with minimal quality impact
  • Progress tracking with real-time status updates. See encoding progress and estimated output size as the compression runs
  • 100% local WebAssembly processing. Your videos stay on your device throughout the entire compression process, ensuring complete privacy

How It Works

  1. 1

    Select your video file

    Click the upload area or drag and drop any video file. The tool accepts MP4, MOV, AVI, MKV, WebM, and virtually any other video format of any size.

  2. 2

    Choose compression settings

    Set a target file size in MB (e.g., 25 MB for email attachments), or use the quality slider for manual control. Optionally scale down the resolution for additional size savings.

  3. 3

    Optional: scale resolution

    Reduce resolution to dramatically shrink file size. Scaling 4K to 1080p can reduce file size by 50-75% while maintaining excellent visual quality on most screens.

  4. 4

    Compress and download

    Click Compress. WebAssembly re-encodes your video with optimized settings locally in your browser. When complete, your compressed MP4 downloads automatically.

Who Should Use This Tool

Professionals compressing videos to meet email attachment size limits (typically 25 MB)
Content creators optimizing videos for faster website loading and better user experience
Social media managers preparing videos for platforms with file size restrictions
Students submitting video assignments that must stay under submission size limits
Anyone running low on device storage who wants to shrink large video collections
Developers optimizing video assets for web and mobile applications

Frequently Asked Questions

How much can I compress a video without losing quality?

At quality settings above 80, the quality loss is nearly imperceptible to most viewers. You can typically reduce file size by 30-50% at these settings. Going below 50 on the quality slider will produce visible artifacts but much smaller files.

What is CRF and how does it affect compression?

CRF (Constant Rate Factor) is the encoding parameter that controls quality. Lower CRF values (18-23) produce higher quality and larger files. Higher CRF values (28-35) produce lower quality and smaller files. Our tool maps the quality slider to CRF values automatically.

Can I compress a video to an exact file size?

The target file size mode does its best to hit your specified size, but exact results depend on the video content. Complex, high-motion videos are harder to compress than simple, static content. Results are typically within 10-20% of the target.

What output format does the compressor produce?

All videos are output as H.264 MP4, which offers the best balance of compression efficiency and universal compatibility. Your compressed video will play on virtually any device.

Do my videos get uploaded to a server?

No. All compression happens locally in your browser using WebAssembly technology. Your video is read, processed, and saved entirely on your device. Nothing is transmitted over the network.

What's the maximum video size I can compress?

There is no server-enforced limit. The practical limit is your device's available RAM. Typically 2-4 GB. Very large files (2 GB+) work best on desktop browsers with more memory.

Does reducing resolution help with compression?

Yes, significantly. Scaling 4K (3840x2160) down to 1080p (1920x1080) reduces the pixel count by 75%, which can reduce file size by 50-75% even at high quality settings.

Are there any limits on how many videos I can compress?

No limits. Compress as many videos as you want. No daily caps, no watermarks, no registration, no hidden costs.

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