How to convert a .SFK file online
Three steps, all tab.
Open your file
Drop your .SFK 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 .SFK 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 .SFK file?
Everything worth knowing about Sound Forge Peak (audio waveform cache) File.
An SFK file is a waveform cache generated automatically by Sound Forge or VEGAS Pro next to an audio file; it holds no sound, only the visual waveform data. You cannot play or convert it. It is safe to delete; the program rebuilds it when you next open the matching audio file.
Programs that open .SFK files
- Windows
- Hex editor (e.g. HxD), MAGIX/Sony Sound Forge (Pro), MAGIX/Sony VEGAS Pro
| Full name | Sound Forge Peak (audio waveform cache) File |
|---|---|
| Developer | Sonic Foundry → Sony → MAGIX → Boris FX (Sound Forge / VEGAS Pro) |
| First released | 1990s (Sonic Foundry Sound Forge); replaced the older .sfl peak format |
| Category | Audio & Video |
| MIME type | application/octet-stream |
Related viewers
Other free tools to open and preview your files.
Is my .SFK file uploaded to a server?
No. Your .SFK 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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