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Play a ISMA video online, free

Play and convert .ISMA files online. Watch video, inspect tracks and convert to MP4, WEBM or MP3, free.

Drop your .ISMA file here

Opens your .ISMA file right here.

Choose file
Inspect up to 4 GB · convert up to ~500 MB
Instant. Opens in seconds
Real FFmpeg compiled to WebAssembly
100% free. No watermarks
Engines load only when needed: MediaInfo (2.4 MB) to inspect, FFmpeg (32 MB, cached after first use) to convert.

How to convert a .ISMA file online

Three steps, all tab.

01

Open your file

Drop your .ISMA file and every video, audio and subtitle track inside is listed with its codec, resolution, frame rate and language.

02

Preview

See frames from across your .ISMA file before you convert, even when your browser can't play the codec inside.

03

Convert

Pick MP4, WEBM or MP3, or repack to MKV without re-encoding. Play the result right here, then download it.

What is a .ISMA file?

Everything worth knowing about IIS Smooth Streaming Audio File.

An ISMA file is an IIS Smooth Streaming Audio File developed by Microsoft. This type of audio file contains sound data used for streaming purposes. These files are typically opened and managed using Microsoft IIS.

Programs that open .ISMA files

Windows
Microsoft IIS
.ISMA format details
DeveloperMicrosoft
CategoryAudio & Video

Related viewers

Other free tools to open and preview your files.

Is my .ISMA file uploaded to a server?

No. Your .ISMA 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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