How to convert a .SD file online
Three steps, all tab.
Open your file
Drop your .SD 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 .SD 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 .SD file?
Everything worth knowing about Entropic ESPS Sound Data File.
An SD file is most likely an Entropic ESPS Sound Data file, a speech audio format from 1980s and 1990s computational linguistics research. The software that created it (WAVES+/ESPS) was discontinued after Microsoft acquired Entropic in 1999. Use Awave Studio on Windows or SoX on Linux to convert it to WAV.
Programs that open .SD files
- Windows
- Avid Pro Tools, Awave Studio
- macOS
- Awave Studio, Avid Pro Tools
- Linux
- SoX (Sound eXchange)
| Full name | Entropic ESPS Sound Data File |
|---|---|
| Developer | Entropic Research Laboratories (acquired by Microsoft in 1999; software subsequently discontinued) |
| First released | circa 1985–1988 (Entropic ESPS toolkit; exact release date unconfirmed) |
| Category | Audio & Video |
| MIME type | application/octet-stream |
| Signature | 00 00 77 A0 (ESPS magic number 0x0000_77A0 (big-endian) or 0xA077_0000 (little-endian)) |
Related viewers
Other free tools to open and preview your files.
Is my .SD file uploaded to a server?
No. Your .SD 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.
Was this tool helpful?
Your rating helps us decide which tools to improve next.