# Convert ASF to WebM

> Convert ASF to WebM online for free. Runs entirely in your browser, so your files never leave your device. Fast batch conversion, no sign-up, no watermarks.

URL: https://www.converterrr.com/asf-to-webm

- Runs in the browser with FFmpeg (WASM): files are not uploaded, and no credits are used.
- Engines: FFmpeg (WASM) (browser), FFmpeg (cloud).
- API: available. `POST /api/v1/jobs` with `"output_format": "webm"` (paid plans).
- More: [Video converter](https://www.converterrr.com/video-converter), [ASF converter](https://www.converterrr.com/asf-converter).

## How to convert ASF to WebM

1. **Add your ASF files.** Drag and drop ASF files onto the converter, paste them, or click to browse. You can add several at once.
2. **Choose WebM.** WebM is already selected. Open Options if you want to change quality, size or metadata.
3. **Convert.** Click Convert. Your files are converted right in your browser in seconds.
4. **Download your WebM.** Download each WebM file, or everything at once as a ZIP.

## Good to know

- ASF files are typically used for legacy Windows Media streams, while WebM is best for video on websites and in browsers.
- This conversion runs on FFmpeg (WASM), running locally in your browser — nothing is uploaded and it works even on slow connections.

## ASF vs WebM

|  | ASF | WebM |
| --- | --- | --- |
| Full name | Advanced Systems Format | WebM Video |
| Type | Video | Video |
| Extensions | .asf | .webm |
| MIME type | video/x-ms-asf | video/webm |
| Best for | legacy Windows Media streams | video on websites and in browsers |
| Properties | legacy format | lossy compression, open standard |

**ASF:** ASF is Microsoft's streaming container behind WMV and WMA files.

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

The other way around: [convert WebM to ASF](https://www.converterrr.com/webm-to-asf).

## Related conversions

- [WebM to ASF](https://www.converterrr.com/webm-to-asf) (in the browser)
- [ASF to MP4](https://www.converterrr.com/asf-to-mp4) (in the browser)
- [MP4 to WebM](https://www.converterrr.com/mp4-to-webm) (in the browser)
- [ASF to MP3](https://www.converterrr.com/asf-to-mp3) (in the browser)
- [MOV to WebM](https://www.converterrr.com/mov-to-webm) (in the browser)
- [ASF to WebP](https://www.converterrr.com/asf-to-webp) (in the browser)
- [GIF to WebM](https://www.converterrr.com/gif-to-webm) (in the browser)
- [ASF to MOV](https://www.converterrr.com/asf-to-mov) (in the browser)
- [MKV to WebM](https://www.converterrr.com/mkv-to-webm) (in the browser)
- [ASF to GIF](https://www.converterrr.com/asf-to-gif) (in the browser)
- [AVI to WebM](https://www.converterrr.com/avi-to-webm) (in the browser)
- [ASF to WAV](https://www.converterrr.com/asf-to-wav) (in the browser)

## Convert ASF to other formats

[ASF to MP4](https://www.converterrr.com/asf-to-mp4), [ASF to MP3](https://www.converterrr.com/asf-to-mp3), [ASF to WebP](https://www.converterrr.com/asf-to-webp), [ASF to MOV](https://www.converterrr.com/asf-to-mov), [ASF to GIF](https://www.converterrr.com/asf-to-gif), [ASF to WAV](https://www.converterrr.com/asf-to-wav), [ASF to MKV](https://www.converterrr.com/asf-to-mkv), [ASF to M4A](https://www.converterrr.com/asf-to-m4a), [ASF to AVI](https://www.converterrr.com/asf-to-avi), [ASF to FLAC](https://www.converterrr.com/asf-to-flac), [ASF to AAC](https://www.converterrr.com/asf-to-aac), [ASF to OGG](https://www.converterrr.com/asf-to-ogg), [ASF to WMV](https://www.converterrr.com/asf-to-wmv), [ASF to Opus](https://www.converterrr.com/asf-to-opus), [ASF to FLV](https://www.converterrr.com/asf-to-flv), [ASF to M4V](https://www.converterrr.com/asf-to-m4v), [ASF to MPEG](https://www.converterrr.com/asf-to-mpeg), [ASF to 3GP](https://www.converterrr.com/asf-to-3gp), [ASF to WMA](https://www.converterrr.com/asf-to-wma), [ASF to MPG](https://www.converterrr.com/asf-to-mpg), [ASF to TS](https://www.converterrr.com/asf-to-ts), [ASF to AIFF](https://www.converterrr.com/asf-to-aiff), [ASF to AMR](https://www.converterrr.com/asf-to-amr), [ASF to VOB](https://www.converterrr.com/asf-to-vob)

## Convert other formats to WebM

[MP4 to WebM](https://www.converterrr.com/mp4-to-webm), [MOV to WebM](https://www.converterrr.com/mov-to-webm), [GIF to WebM](https://www.converterrr.com/gif-to-webm), [MKV to WebM](https://www.converterrr.com/mkv-to-webm), [AVI to WebM](https://www.converterrr.com/avi-to-webm), [WMV to WebM](https://www.converterrr.com/wmv-to-webm), [M4V to WebM](https://www.converterrr.com/m4v-to-webm), [3GP to WebM](https://www.converterrr.com/3gp-to-webm), [FLV to WebM](https://www.converterrr.com/flv-to-webm), [MPEG to WebM](https://www.converterrr.com/mpeg-to-webm), [TS to WebM](https://www.converterrr.com/ts-to-webm), [MPG to WebM](https://www.converterrr.com/mpg-to-webm), [MTS to WebM](https://www.converterrr.com/mts-to-webm), [VOB to WebM](https://www.converterrr.com/vob-to-webm), [M2TS to WebM](https://www.converterrr.com/m2ts-to-webm), [APNG to WebM](https://www.converterrr.com/apng-to-webm), [OGV to WebM](https://www.converterrr.com/ogv-to-webm), [MXF to WebM](https://www.converterrr.com/mxf-to-webm), [DivX to WebM](https://www.converterrr.com/divx-to-webm), [3G2 to WebM](https://www.converterrr.com/3g2-to-webm), [RM to WebM](https://www.converterrr.com/rm-to-webm), [RMVB to WebM](https://www.converterrr.com/rmvb-to-webm), [F4V to WebM](https://www.converterrr.com/f4v-to-webm)

## ASF to WebM: frequently asked questions

### How do I convert ASF to WebM?

Drop your ASF file onto the converter above, make sure WebM is selected, and click Convert. When it's done, download the WebM file — it usually takes a few seconds.

### Is it safe to convert ASF to WebM here?

Yes. ASF to WebM conversion happens entirely inside your browser using WebAssembly, so your file is never uploaded to any server.

### Is the ASF to WebM converter free?

Yes — free with no watermark. Signed-out visitors can convert 25 files a day, and a free account raises that to 250.

### Will converting ASF to WebM reduce quality?

WebM is a lossy format, but our defaults are tuned to be visually indistinguishable for most files. You can raise the quality under Options.

### Can I convert multiple ASF files at once?

Yes. Add up to 5 files at a time without an account, 10 with a free account and up to 500 on paid plans, then download them individually or as a single ZIP.

### Can I convert WebM back to ASF?

Yes — use our WebM to ASF converter. Note that converting back and forth between formats can't recover detail lost to lossy compression.