Turn your ASF file into an MP4 that plays where you need it, right in your browser.
Drag and drop the file, or click to browse. Files up to 500 MB are supported, and nothing is installed.
MP4 is already selected, so there is nothing to configure. You can switch formats in the panel if you need to.
We convert on our servers, usually in under a minute. Create a free account to download the MP4, or keep editing the file in REQO.
ASF is the container Microsoft built for streaming Windows Media. WMV and WMA files are ASF underneath, and a plain .asf carries the same codecs with the same problem: it stops at the edge of the Windows ecosystem.
The practical problem: macOS, iOS, Android and browsers need extra software and usually still fail. Cannot be embedded on a web page at all. Windows Media codecs are generations behind H.264 on efficiency.
MP4 solves that. Plays natively on every phone, browser, TV and editing app with no extra codecs. Every upload form accepts it, from YouTube and LinkedIn to Slack and email. H.264 keeps files small enough to send while still looking sharp at 1080p.
ASF is the container underneath Windows Media. Like WMV, it works fine until the file has to leave Windows, at which point nothing opens it. One conversion to MP4 makes an old media-library file shareable again.
| ASF | MP4 | |
|---|---|---|
| Container | Advanced Systems Format (Microsoft) | MPEG-4 Part 14 |
| Typical codecs | Windows Media Video and Audio | H.264 video, AAC audio |
| Best for | Legacy Windows Media libraries | Sharing anywhere, uploads, web embeds |
| Plays on | Windows Media Player | Every phone, browser, TV and editor |
| File size | Moderate, dated compression | Small for the quality |
Yes. Convert and preview the result for free, then create a free account to download it. There is no per-file charge and no watermark on the MP4 itself beyond the free-plan badge.
No. The conversion runs on our servers and the whole flow happens in your browser, so it works the same on Windows, macOS, Linux, iPhone and Android.
Converting re-encodes the video, so it is not bit-for-bit identical. We encode at a high quality target, which keeps the result visually indistinguishable from the ASF on normal viewing. Converting the same file back and forth repeatedly will eventually show, so keep your original.
Up to 500 MB per file. For anything bigger, trim or compress it first, both are free tools here.
Your upload is processed and then held only as long as your project needs it. Nothing is published, indexed or shared unless you create a share link yourself.
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OpenFree, in your browser, and the file stays open in a full video editor afterwards.