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Video Compressor

Upload a video to compress it with adjustable quality settings — processed locally, no upload.

Files never leave your browser

Quality — Medium Quality

High quality = larger file · Low quality = smaller file

All processing happens in your browser — your files are never uploaded.

How to use Video Compressor

The Video Compressor reduces the file size of MP4, WebM, MOV and MKV videos by re-encoding them at a lower bitrate using H.264 or H.265 — all processed locally in your browser without uploading your footage anywhere. Compress large recordings, drone footage or screen captures before emailing, uploading to a CMS or posting to social media while retaining acceptable visual quality.

  1. Click "Select Video" and open the video file you want to compress.
  2. Choose the target quality level using the CRF slider (lower CRF = higher quality and larger file; try CRF 28 as a starting point).
  3. Select the output codec — H.264 for maximum compatibility, H.265 for better compression.
  4. Optionally set a maximum output resolution to further reduce file size.
  5. Click Compress and monitor the progress bar; download the compressed video when done.

Your data never leaves your device — 100% private processing.

Understanding CRF and target bitrate

Constant Rate Factor (CRF) is the primary quality control for H.264 and H.265 encoding. CRF 0 is lossless; CRF 51 is the worst quality. For H.264 a CRF of 18–28 is considered visually acceptable for most content, with 23 being the default. H.265 (HEVC) achieves similar visual quality at roughly half the bitrate of H.264 at the same CRF, making it the better choice when compatibility with older devices is not required. Target bitrate mode is an alternative that constrains file size but may vary quality across scenes.

H.264 CRF quality guide
CRFPerceived qualityRelative file size
18Visually losslessVery large
23High (default)Medium-large
28AcceptableMedium
35Noticeable artefactsSmall

H.264 vs H.265 for compression

H.264 (AVC) is the most universally supported video codec — playable on virtually every device, browser and platform without any additional software. H.265 (HEVC) delivers significantly better compression, achieving the same perceived quality at roughly half the bitrate, but requires hardware or software decoder support that older devices and some browsers may lack. For files destined for modern platforms (YouTube, Vimeo, recent mobile devices), H.265 is excellent. For maximum reach including older smart TVs and legacy browsers, H.264 is safer.

Glossary

CRF (Constant Rate Factor)
A quality-based encoding mode for H.264/H.265 where a single number from 0 (lossless) to 51 (worst) controls overall quality and file size.
Bitrate
The number of bits used per second of video; higher bitrate means better quality and larger file size.
H.264 (AVC)
Advanced Video Coding; the most widely supported lossy video codec, balancing quality, compression and compatibility.
H.265 (HEVC)
High Efficiency Video Coding; achieves roughly 50% better compression than H.264 at equivalent quality but requires modern decoder support.
Lossy compression
A compression method that permanently discards some data to achieve smaller file sizes; video quality decreases with each re-encode.

Related reading

Frequently Asked Questions

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Why use Video Compressor?

  • Powered by FFmpeg running directly in the browser — no upload needed
  • Supports all major video and audio formats
  • Lossless and lossy options for quality control
  • Export results immediately without waiting for cloud processing

Common use cases

  • Compress a video before uploading to Google Drive
  • Extract audio from a video lecture for easy listening
  • Trim a video clip for a social media reel
  • Convert MOV files to MP4 for cross-platform compatibility
  • Merge two audio tracks for a podcast episode

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