Video Compressor
Reduce the file size of MP4, WebM and MOV videos in your browser. Choose a resolution and quality level, then download the smaller result — processing runs locally in your browser.
How to compress a video online
Drop a video file into the tool, pick a target resolution and quality, then click Compress Video. By default, the existing browser-local engine processes the file in your tab. The file stays on your device while FFmpeg.wasm processes it in your browser.
Choosing a resolution
Lowering the resolution is the single biggest way to shrink a video. Keep Original for a file you'll edit further, drop to 1080p or 720p for sharing online, or use 480p when file size matters more than sharpness, such as a quick preview or a messaging app upload.
Choosing a quality level
High quality keeps more visual detail at a higher bitrate. Balanced is a good default for most clips. Smaller file pushes the bitrate down further, which is useful for long recordings or when you're close to an upload limit.
Output format
The compressed file is created as MP4 with H.264 video and AAC audio by FFmpeg.wasm. If the FFmpeg engine cannot start, NeroTool can fall back to a browser-supported recording format.
Privacy and processing
NeroTool supports a browser-local fallback using Canvas and MediaRecorder. FFmpeg.wasm processes the selected video locally in your browser; the video is not uploaded to a conversion server.
Common issues
- Keep the browser tab open and active until compression finishes — switching tabs can pause frame capture in some browsers.
- Very long or high-resolution source videos take longer and use more memory.
- If the tool reports no browser support, try a recent desktop version of Chrome or Edge.
Best use cases and practical tips
The Video Compressor is useful whenever a clip is too large to upload, attach or share quickly. Compress a screen recording before sending it in chat, shrink a phone video before posting it, or reduce a long recording before archiving it.
- Keep a copy of the original file if you may need full quality again later.
- Preview the compressed result before deleting the source video.
- For very large files, try a lower resolution first to keep processing time reasonable.
Reduce video size for uploads and sharing
Video files become large quickly because they contain many high-resolution frames. Compression reduces resolution, quality or both so a clip is easier to upload, send and store. The right target depends on whether the video is for messaging, a website, an archive or a larger screen.
Choose resolution before chasing maximum compression
Reducing a 1080p video to 720p can save substantial space when full HD detail is unnecessary. For smaller previews, 480p may be sufficient. After compression, watch a representative section and check that text, motion and important details remain clear.
Need a different format instead? Use Video to Video. To extract only the soundtrack, use the Video to MP3 workflow.
Frequently asked questions
Is my video uploaded to a server?
No upload is needed. Your video is processed locally in your browser with FFmpeg.wasm.
What video formats can I compress?
You can load most formats your browser can already play, including MP4, WebM and MOV. The compressed download is saved as WebM, or MP4 on browsers that support recording that format.
Will compressing reduce video quality?
Yes, to some degree. Lowering the resolution and choosing a smaller-file quality setting reduces the bitrate, which is what makes the file smaller. Balanced settings keep most videos watchable while cutting file size significantly.
Is there a maximum file size?
Yes, the tool accepts files up to 500 MB, since compression happens in your browser's memory. Very long or high-resolution videos may also take a while to process.
Why does the tool say my browser is not supported?
FFmpeg.wasm needs a modern browser with WebAssembly and Web Workers. Use a recent desktop version of Chrome or Edge for the most reliable experience.