Video Compressor
Free online video compression tool. Adjust bitrate and resolution, supports MP4, WebM, AVI, MOV formats. Fully local processing, privacy guaranteed.
Drag video files here or click to upload
Supports MP4, WebM, AVI, MOV formats, max 2GB
How to Use the Video Compressor
Compress your video in 4 easy steps, all locally in your browser
Upload Video File
Click the upload button or drag your video into the upload area. Supports MP4, WebM, AVI, MOV and more.
- Drag & drop supported
- Max file size: 2GB
- Supports MP4/WebM/AVI/MOV
Adjust Settings
Choose a quality preset (High Compression / Balanced / High Quality) or manually set bitrate and resolution.
- Quick preset selection
- Custom bitrate support
- Resolution scaling
Start Compression
Click 'Start Compression'. FFmpeg.wasm will process the video locally in your browser without any upload.
- Real-time progress
- Background thread – no UI freeze
- Live compression log
Download Result
After compression, compare before/after file sizes and download the compressed video.
- Before/after comparison
- One-click download
- Re-compress anytime
Why Choose Our Free Online Video Compressor
Browser-based video compression powered by FFmpeg.wasm – no upload, no privacy risk
Privacy First
100% Local Processing
All compression happens in your browser. Your video files are never uploaded to any server.
Data Stays on Device
Sensitive content never leaves your device, eliminating any data breach risk.
Flexible Controls
Bitrate Control
Set custom bitrate from 100 to 20000 kbps to precisely balance quality and file size.
Resolution Scaling
Choose from 360p to 4K presets or set a custom width/height.
Wide Format Support
Multiple Input Formats
Accepts MP4, WebM, AVI, MOV and more as input.
MP4 Output
Outputs H.264-encoded MP4 for maximum device compatibility.
Completely Free
No Limits
No file size limit, no usage cap, no feature restrictions – free forever.
No Registration
No account or software installation required. Just open the page and use it.
Use Cases
Video compression for social media, email, websites, and more
Social Media Upload
Compress videos to meet file size limits on YouTube, TikTok, Instagram, and more.
Email Attachments
Reduce video size to fit within email attachment limits and share easily.
Website Optimization
Compress embedded videos to speed up page load time and improve user experience.
Free Up Storage
Batch compress video archives to free up disk space with minimal quality loss.
Mobile Compatibility
Lower resolution and bitrate for smooth playback on mobile networks.
Video Archiving
Compress high-bitrate raw footage for long-term storage at lower cost.
How FFmpeg.wasm Compression Works
Technical overview of the compression pipeline
Parse Input
FFmpeg parses the video container, codec, bitrate, resolution, and other metadata.
Decode
The video stream is decoded into raw uncompressed frame data.
Re-encode
H.264 encoder re-compresses the frames at the specified bitrate and resolution.
Mux Output
The compressed video stream is muxed into an MP4 container and made available for download.
Compression Strategy Comparison
Bitrate Control (ABR)
Encodes at a specified average bitrate, resulting in predictable file size.
- Predictable output size
- Suitable for fixed bandwidth
- Faster processing
Ideal when file size is the primary concern.
Quality Control (CRF)
Encodes based on visual quality; file size varies with content.
- More stable quality
- Better overall results
- Recommended for archiving
Ideal when quality is the primary concern.
Technical Details
Core Technology
FFmpeg.wasm
Video Codec
H.264 (libx264)
Audio Codec
AAC
Output Format
MP4
Processing
Browser Local
Max File Size
2 GB
What Is Video Compression
Learn about video compression principles and how bitrate and resolution affect quality
Definition
Video compression reduces file size by eliminating redundant data in video streams. Codecs like H.264 use inter-frame prediction and transform coding to dramatically reduce storage while maintaining visual quality. Bitrate – the amount of data per second – is the core parameter that controls the quality-to-size tradeoff.
Key Parameters Explained
Video Bitrate
Controls data per second (kbps). Higher bitrate = better quality but larger file size.
Resolution
The pixel dimensions of the video. Reducing resolution significantly decreases file size.
CRF Quality Factor
H.264 constant quality parameter (0–51). Lower value = better quality. Automatically mapped in presets.
快速提示
- 本地处理，隐私安全
- H.264 编码，兼容性最强
- 支持多种格式输入
Preset Comparison
| Preset | Bitrate Range | Resolution | Use Case | Compression Ratio |
|---|---|---|---|---|
| High Compression | 200–800 kbps | May reduce | Web sharing, messaging | 60–80% |
| Balanced | 800–2500 kbps | Keep original | Social media upload | 30–60% |
| High Quality | 2500–5000 kbps | Keep original | Archiving, backup | 10–30% |
Actual compression ratio varies based on the original video codec and content complexity.
Frequently Asked Questions
Common questions about our online video compression tool
Will the video quality noticeably degrade after compression?
What input video formats are supported?
Is there a file size limit?
Is my video uploaded to a server?
How should I set the bitrate?
How long does compression take?
Can I use this on mobile devices?
Is the tool free? Are there any usage limits?
User Reviews
Real feedback from users around the world
Sarah M.
Content Creator
Compressed an 800MB video down to under 200MB for Instagram. Quality was still great and no upload needed – perfect!
John D.
Corporate Trainer
Training recordings were too large to email. This tool solved it instantly, and I love that my files stay private.
Alex K.
Web Developer
As a developer, I really appreciate the local processing approach. FFmpeg.wasm performance exceeded my expectations.
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