🎬 Video Compressor

Compress MP4, WebM, MOV — no upload, no signup, no watermark

✓ Free Forever · ✓ No Signup · ✓ No Upload · ✓ Works Offline

🔒 Your image never leaves your device. All processing happens locally in your browser using FFmpeg.wasm (H.264 / AAC, runs entirely in your browser). No upload, no server, no tracking.

Features

  • Zero Upload — Your video file never leaves your device. Compression runs on your CPU via WebAssembly — verifiable in DevTools Network tab.
  • Adjustable Quality — Pick the CRF level (18-35) to balance file size vs. visual quality. Preview both before downloading.
  • Up to 90% Smaller — H.264 re-encoding typically shrinks file size 50-90% with minimal visible quality loss.
  • No Watermark, No Signup — Unlike Clipchamp, Veed, or online compressors — no account, no watermark, no time limit.

How It Works

  1. Drop your video — MP4, WebM, MOV, AVI, MKV — any common format. Up to 1 GB to stay within browser memory limits.
  2. Pick a quality level — CRF 23 = visually lossless, 28 = balanced (default), 32 = small file. Move the slider to choose.
  3. Wait for compression — FFmpeg.wasm engines loads once (~30 MB), then compresses on your CPU. Expect 1-3x the video length for a typical compression.
  4. Compare and download — Preview original vs. compressed side-by-side, then download the MP4. The original is never touched.

Use Cases

  • Shrink videos under email attachment limits (Gmail 25 MB, Outlook 20 MB)
  • Send videos via WhatsApp, Telegram, Discord without quality loss from auto-compression
  • Speed up web pages by serving smaller MP4 hero videos
  • Save space on your phone — compress old recordings before archiving
  • Reduce upload time before posting to YouTube, TikTok, Instagram

Frequently Asked Questions

Does the video upload to your server?

No. The video stays in your browser's memory the entire time. The only network request is loading the FFmpeg engine (~30 MB) from a public CDN the first time you use the tool. Open DevTools → Network tab to verify — you'll see the FFmpeg files load, but no upload of your video.

Why is it slower than online compressors that use servers?

Server-based tools use dedicated GPUs/CPUs. ToolKoala runs FFmpeg.wasm on your laptop's CPU through WebAssembly. The trade-off is privacy: your video never leaves your device. Expect 1-3x the video length to compress (a 60-second clip takes 1-3 minutes).

What's the maximum file size?

We cap uploads at 1 GB to stay within browser memory limits. For files over 1 GB, compress with a desktop tool like HandBrake. For files under 500 MB, the experience is smooth on most laptops.

What does CRF mean?

Constant Rate Factor — H.264's quality knob. Lower = better quality, larger file. 18 = visually lossless, 23 = high quality, 28 = balanced (good default), 32 = noticeable compression, 35 = aggressive shrink.

Does it work on mobile?

Technically yes, but compression is CPU-heavy. Phones may slow down or run out of memory for large files. We recommend desktop or laptop for files over 100 MB.

Why H.264 and not H.265 or AV1?

H.264 has universal device support (every phone, browser, smart TV). H.265 and AV1 produce smaller files but aren't universally playable yet.

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