Video Compressor — Reduce Video File Size Online
A video compressor reduces the file size of your videos so they're easier to share via email, messaging apps, or social media, and take less storage space. Our free online compressor runs 100% in your browser: on modern browsers it uses your device's built-in hardware video encoders (WebCodecs), which is dramatically faster than server-free WebAssembly encoding; older browsers automatically fall back to a WebAssembly FFmpeg engine.
Unlike tools that upload your videos to remote servers, this compressor runs 100% in your browser. Your videos are never uploaded, stored, or transmitted anywhere. This makes it completely private and secure.
Choose from quality presets (Low, Medium, High), set a target resolution, or use the advanced CRF control for precise compression. The tool supports MP4, WebM, AVI, MOV, MKV, and FLV input formats.
How to Compress a Video
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Upload your video Drag and drop a video file onto the upload area, or click to browse. We support MP4, WebM, AVI, MOV, MKV, and FLV.
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Choose settings Select an output format (MP4 or WebM), pick a quality preset, set a target resolution, or use advanced CRF settings.
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Compress Click "Compress Video" and watch the progress bar. The video engine loads automatically on first use (cached for future visits).
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Download Review the before/after comparison and click "Download" to save your compressed video.
Frequently Asked Questions
No, never. All video compression happens entirely in your browser using FFmpeg compiled to WebAssembly. Your videos are never uploaded, stored, or transmitted anywhere — making this tool completely private and secure.
On modern browsers compression uses your device's built-in hardware video encoders via the WebCodecs API, so there is nothing to download. Older browsers fall back to a WebAssembly FFmpeg engine (~30MB, downloaded once and cached), which is why their first compression can take longer. Video compression is also CPU-intensive — larger videos take longer to process.
Quality presets (Low, Medium, High) are easy-to-use settings that balance file size and quality automatically. CRF (Constant Rate Factor) is an advanced setting where lower values mean better quality but larger files. CRF 18 is visually lossless, 23 is default, and 28+ produces much smaller files.
MP4 (H.264) is the most widely compatible format — it works on virtually all devices and platforms. WebM (VP8) is a modern open format that produces smaller files but may not play on older devices. When in doubt, choose MP4.
There's no hard limit, but very large videos (several GB) may consume a lot of memory and take a long time to compress. For best results, keep videos under 2GB. Mobile devices may struggle with very large files.
Compress Video Without Losing Quality
Quality loss depends on how aggressively you compress. For most content, CRF 20–23 at your original resolution looks identical to the source while cutting file size by 40–70%. This tool's Medium preset is tuned for that balance. Use the High preset for archival copies and footage you'll re-edit; use Low when size matters more than fidelity, and drop to 720p or 480p for quick sharing.
Compress a Video Without Uploading It
Most online compressors upload your file to their servers before encoding. This one does not: on modern browsers it uses your device's built-in hardware video encoders through the WebCodecs API, so your video never leaves your computer or phone. That makes it safe for private, confidential, or regulated footage — nothing is transmitted, stored, or logged anywhere.
Compress Large Videos for Email, WhatsApp and Discord
Common platform limits and the settings that hit them:
- Email attachments (25MB — Gmail, Outlook): 480p, Low preset — a 10-minute clip typically lands well under 25MB.
- WhatsApp status / media (16MB): 360p or 480p, Low preset, MP4 output.
- Discord free upload (10MB): 480p, Low preset; if it's still over, shorten the clip or pick 360p.
- Telegram and messaging apps (2GB): 720p, Medium preset keeps quality high while halving the file.
Free Video Compressor, No Watermark, No Signup
There's nothing to install, no account to create, no watermark on your output, and no hidden file-size fee. Compression runs on your own hardware at hardware-accelerated speed — typically finishing a job in seconds to minutes that software-only tools take tens of minutes to complete.
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