Drop your input and pick the compression level - higher levels trade quality for byte savings. Choose Smaller file for the biggest size reduction, Balanced for everyday sharing, or Higher quality when you want to keep as much detail as possible while still shrinking the file. The output keeps your original file extension and downloads with a "-compressed" suffix once FFmpeg.wasm finishes re-encoding it in this tab. Only video files are accepted here - an audio-only upload shows a clear error instead of a broken result.
For the tasks this tool is and is not a fit for, see the when to use Video Compressor guide.
Video Compressor
Video Compressor shrinks the byte size of a video file inside this browser tab. Pick one of three compression levels, choose your mp4, mov or webm file, and download the smaller result. Balanced is preselected and suits everyday sharing; the re-encode runs on your own device, so the video is never uploaded.
Output is downloadable immediately after processing, and your original input is not retained beyond the page session.
Key features
- Pick one of three fixed presets - Smaller file, Balanced, or Higher quality - before choosing your video; there is no control for an exact target file size or bitrate, only the three levels.
- Balanced is already selected when the page loads, so a single file pick is enough for a typical email or chat attachment.
- The output keeps the same file type as your input, just smaller, downloaded with a "-compressed" suffix.
- The whole re-encode runs entirely in this browser tab via FFmpeg.wasm, so your video is never uploaded to a server.
- Video containers only: an audio-only upload such as mp3, wav, aac, ogg, flac or m4a stops with a clear error instead of a broken result.
- Because it runs single-threaded on your device rather than a server, large 4K or high-bitrate files can take several minutes.
- Compression always re-encodes the video, so there is some quality loss even at the Higher-quality setting.
Which codec each container uses
The codec the re-encode uses depends on your input's container - each container keeps its own native codec pairing rather than being forced onto a single codec.
| Input container | Video codec | Audio codec |
|---|---|---|
| mp4, mov, avi, mkv | H.264 | AAC at 128 kbps |
| webm | VP9 | Opus at 96 kbps |
What each compression level actually changes
Each level sets a constant-quality value rather than a target size, which is why the finished byte count depends on your source footage. Lower numbers keep more detail.
| Level | H.264 quality value | VP9 quality value |
|---|---|---|
| Smaller file | 32 | 36 |
| Balanced (preselected) | 28 | 32 |
| Higher quality | 23 | 28 |
How Video Compressor compares with a desktop app or an upload service
| Aspect | Video Compressor | Desktop application | Upload-based online service |
|---|---|---|---|
| Where your file goes | Stays on this device - runs in the browser | Stays on this device | Uploaded to a server |
| Install required | No - one-time browser download of the roughly 31 MB FFmpeg engine, then reused in the same tab | Yes, typically 50-200 MB | No |
| Quality control | 3 fixed levels | Many custom sliders (bitrate, resolution, codec, two-pass) | Usually 1-3 preset levels, varies by service |
| Large 4K file speed | Single-threaded in your browser - can take several minutes | Often faster, using your full processor | Depends on the service and your upload speed |
The browser route fits a quick, private, one-off compression for email, chat, storage, or a size-limited upload form. A desktop application is the better answer when you need a precise bitrate or resolution, or when you compress large 4K files often and want the extra speed.
When to use another tool
If you only need to cut a clip or drop the audio track with no quality loss at all, use the trim or strip-audio tools instead. For format conversion, see the related-tools section, and the video tools hub lists the rest of the set. For the tasks this tool is and is not a fit for, see when to use Video Compressor.
Frequently Asked Questions
What does Video Compressor do?
It shrinks the byte size of a video file right in your browser, keeping the same container format, and lets you download the smaller file as soon as processing finishes.
When should I reach for video compressor?
Reach for it when a clip is too large to email, upload, or share and you want a smaller file without changing its format - pick one of the compression presets and the tool re-encodes the video to a lighter size, trading some visual quality for the space you save.
What complementary tools work well alongside video compressor?
For format conversion, see the related-tools section.
Can I pick an exact output file size?
No. There are only the three fixed levels - Smaller file, Balanced, or Higher quality - with no exact-size or exact-bitrate target, so the finished byte count depends on your source footage.
Is the result as good as a desktop application at similar settings?
It is comparable at the same constant-quality target, because the same H.264 or VP9 encoder does the work. A desktop application usually exposes more precise controls - a custom bitrate, a resolution change, or two-pass encoding - that this tool deliberately reduces to three levels.
Do I need an account or an install?
No. The tool runs in the browser tab with no sign-in and nothing to install; the roughly 31 MB FFmpeg engine downloads once per tab before the first compression and is reused after that.