# Compress WebM

> Compress WebM Video (WebM) files online for free. The compressor re-encodes VP9/Opus at a lower bitrate (and resolution on Strong). Runs in your browser, so your files never leave your device. Or set an exact target size.

URL: https://www.converterrr.com/compress-webm

- Compression: lossy, runs in the browser (nothing is uploaded).
- API: `POST /api/v1/jobs` with `"operation": "compress"` and an optional `compression_level` or `target_size` (paid plans).
- Format: [WebM converter](https://www.converterrr.com/webm-converter), [Compress videos](https://www.converterrr.com/compress-videos).

## What compression does to WebM

Re-encodes VP9/Opus at a lower bitrate (and resolution on Strong).

- **Light:** Near-lossless: re-encodes conservatively and keeps the full resolution.
- **Balanced (default):** The default: looks the same for most uses, and typically 40–70% smaller.
- **Strong:** Smallest file: lower quality, and large videos are downscaled.

## Need an exact size?

Set a target size or a percentage to reduce by. These pages preset common video sizes and take WebM too:

- [Compress video to 8 MB](https://www.converterrr.com/compress-video-to-8mb): Chat app uploads
- [Compress video to 10 MB](https://www.converterrr.com/compress-video-to-10mb): 10 MB upload limits
- [Compress video to 25 MB](https://www.converterrr.com/compress-video-to-25mb): Email attachments
- [Compress video to 50 MB](https://www.converterrr.com/compress-video-to-50mb): Portals & bigger uploads
- [Compress video to 100 MB](https://www.converterrr.com/compress-video-to-100mb): Long videos, smaller

## How to compress WebM

1. **Add your WebM files.** Drag and drop WebM files onto the compressor, paste them, or click to browse. You can add several at once.
2. **Pick a level or a target.** Balanced is selected and suits most files. Choose Light to stay closer to the original or Strong for the smallest file, or set a target size or a percentage to reduce by.
3. **Compress.** Click Compress. Your WebM files are processed right in your browser, usually in seconds.
4. **Download.** Download each smaller WebM, or everything at once as a ZIP.

## Good to know

- WebM (VP9 video, Opus audio) is built for the web and already efficient, so the savings come from a lower bitrate and, on Strong, a lower resolution.
- Every major browser plays WebM, which makes it a good format for videos embedded on your own site.
- Need to meet an upload limit? Set a target size (or a percentage to reduce by) in the compressor and the video is compressed to fit.
- WebM compression runs entirely in your browser with WebAssembly, so nothing is uploaded and your files never leave your device.

## About the WebM format

WebM is an open, royalty-free video format designed for the web, using VP8/VP9 or AV1 video with Opus audio.

|  | WebM |
| --- | --- |
| Full name | WebM Video |
| Type | Video |
| Extensions | .webm |
| MIME type | video/webm |
| Best for | video on websites and in browsers |
| Properties | lossy compression, open standard |

## Compress other videos

[Compress MP4](https://www.converterrr.com/compress-mp4), [Compress MOV](https://www.converterrr.com/compress-mov), [Compress MKV](https://www.converterrr.com/compress-mkv), [Compress AVI](https://www.converterrr.com/compress-avi)

## Compressing WebM: frequently asked questions

### How do I compress a WebM file?

Drop the WebM onto the compressor above, keep Balanced or pick another level, and click Compress. Download the smaller WebM when it's done; it usually takes a few seconds.

### Does compressing WebM reduce quality?

A little, by design: WebM is a lossy format. Balanced is tuned to look the same for most uses; choose Light if you want to stay closer to the original.

### How much smaller will my WebM get?

WebM is already efficient, so it depends on the original bitrate. Lowering the resolution on Strong saves the most.

### Can I compress WebM to a specific size?

Yes. Set a target size in the compressor, or a percentage to reduce by, and the file is compressed to land at or just under it.

### Is it safe to compress WebM files here?

Yes. WebM files are compressed inside your browser with WebAssembly and never uploaded to a server.

### Is the WebM compressor free?

Yes. Compression is free with no watermark and no sign-up, within the same daily allowance as conversions.