How to convert a .ISMV file online
Three steps, all tab.
Open your file
Drop your .ISMV file and every video, audio and subtitle track inside is listed with its codec, resolution, frame rate and language.
Preview
See frames from across your .ISMV file before you convert, even when your browser can't play the codec inside.
Convert
Pick MP4, WEBM or MP3, or repack to MKV without re-encoding. Play the result right here, then download it.
What is a .ISMV file?
Everything worth knowing about IIS Smooth Streaming Video File.
An ISMV file is a Microsoft IIS Smooth Streaming Video file, a fragmented MP4 used for HTTP adaptive streaming on Windows IIS servers. Normal media players cannot play it directly, but VLC can open it and FFmpeg converts it to a standard MP4 with one command. The Smooth Streaming technology is legacy: Microsoft Silverlight, its main client, reached end-of-life in October 2021.
Programs that open .ISMV files
- Windows
- VLC media player, FFmpeg, Microsoft IIS (server)
- macOS
- VLC media player, FFmpeg
- Linux
- VLC media player, FFmpeg
| Full name | IIS Smooth Streaming Video File |
|---|---|
| Developer | Microsoft Corporation |
| First released | 2008 (IIS 7.0 Smooth Streaming, Microsoft) |
| Category | Audio & Video |
| MIME type | video/mp4 |
| Signature | 00 00 00 18 66 74 79 70 ("ftyp" MP4/ISO Base Media File Format box (at offset 4)) |
Related viewers
Other free tools to open and preview your files.
Is my .ISMV file uploaded to a server?
No. Your .ISMV file is converted for you. The converted file is created in memory,.
Why is conversion slower than desktop software?
Browsers give web pages a single CPU core for this kind of work and no hardware video encoder. Short clips convert in seconds; for long 4K films a desktop app like HandBrake is faster. Use Start and Length to convert just the part you need.
Which output format should I pick?
MP4 plays on every phone, TV and browser. WEBM is an open format that's great for the web. MP3 keeps only the sound. MKV (no re-encode) is instant and lossless, but only changes the container.
Can I keep all audio tracks and subtitles?
The MKV (no re-encode) option copies every track as-is. MP4 and WEBM keep the first video and audio track, which is what most players use.
Why can't some files be converted?
Files protected with DRM (for example purchased iTunes .m4p songs or some .wmv rentals) are encrypted. We can show what's inside, but nobody can convert them without the key.
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