Video Compressor

Introduction

Compress video files locally in your browser without uploading to servers. Supports adjusting quality, resolution, frame rate, output format, and audio bitrate, with real-time progress and before/after preview—ideal for reducing file size, converting formats, and generating lightweight previews.

Core Features

• Local Processing: All compression completed in browser, no upload needed, protects privacy
• Flexible Configuration: Adjust quality (CRF), resolution, frame rate, format, and audio parameters
• Multi-format Output: Supports MP4, WebM, AVI, MKV formats
• Real-time Preview: Shows comparison of original and compressed video
• Progress Tracking: Real-time display of compression progress
• Mobile Optimization: Prompts confirmation before starting large processing on mobile devices

How to Use

Step 1: Upload Video

1. Click upload area to select video file
2. Supported formats: MP4, MOV, AVI, MKV, WebM, and other common video formats
3. File size limit: Maximum 500MB
4. First-time use may take a moment to initialize (especially on slower devices)

Step 2: Adjust Compression Settings

Video Quality (CRF)

Constant Rate Factor value, controls compression quality and file size:

• 18-22 (Best Quality): High quality, larger file, suitable for scenarios requiring detail preservation
• 23-26 (Balanced): Balance quality and size, recommended default value
• 27-35 (Smaller File): Lower quality, smaller file, suitable for quick preview or network sharing

Lower values mean higher quality and larger size; higher values mean smaller size and reduced quality.

Resolution

Select output video resolution:

• Original: Maintain original resolution
• 1080p (1920x1080): Full HD
• 720p (1280x720): HD
• 480p (854x480): Standard definition
• 360p (640x360): Low definition, suitable for network transmission

Reducing resolution can significantly reduce file size.

Frame Rate (FPS)

Select output video frame rate:

• Original: Maintain original frame rate
• 60 fps: Ultra smooth, suitable for motion videos
• 30 fps: Standard smoothness, recommended default value
• 24 fps: Film standard, smaller file

Reducing frame rate can reduce file size but may affect smoothness.

Output Format

• MP4: Best compatibility, supports all platforms and devices, uses H.264 encoding and AAC audio
• WebM: Suitable for web playback, uses VP9 encoding and Opus audio, smaller size
• AVI: Traditional format, good compatibility but larger size
• MKV: Supports multiple audio tracks and subtitles, suitable for archiving

Audio Quality

Select audio bitrate:

• 64 kbps (Low): Low quality, suitable for voice
• 128 kbps (Standard): Standard quality, recommended default value
• 192 kbps (High): High quality, suitable for music videos
• 256 kbps (Very High): Very high quality, near lossless

Step 3: Start Compression

1. Click "Start Compression" button
2. Wait for processing to finish (shows real-time progress percentage)
3. Large videos may take several minutes, please be patient
4. Success message displays after compression completes

Step 4: Preview and Download

1. Compare original and compressed video in preview area
2. View file size and compression rate statistics
3. Click "Download" button to save compressed video

Use Cases

Video Size Optimization

Reduce video file size for easy email attachment or instant messaging sending. Optimize website video loading speed, improve user experience. Save cloud storage space and traffic costs.

Format Conversion

Unify different format videos to MP4, improve compatibility. Convert to WebM for web playback, reduce bandwidth consumption. Convert high-resolution videos to multiple resolution versions, adapt to different devices.

Quick Preview Generation

Generate low-bitrate preview versions for quick review or drafts. Create lightweight sample or demo videos. Generate video thumbnails or cover images.

Notes

• Timer may have reduced precision in background tabs due to browser power-saving mechanisms
• System sleep or lock will pause timing, continuing after resumption
• All processing completed locally in browser, does not upload videos, protects privacy
• Videos with very high resolution (4K or larger) on low-performance devices may fail
• Recommend testing with small files first to confirm settings before processing complete videos

Privacy Protection

• All video processing completed locally in browser, not uploaded to servers
• Processed video files only saved on your device
• Tool does not collect, store, or analyze your video content

Comparison with Similar Tools

Compared to online video compression services, this tool processes completely locally, protects privacy and has no file size or usage limits. Versus desktop software (like HandBrake), no installation needed but processing power limited by browser. Versus mobile apps, cross-platform and no storage space occupation.