What is the PKF file format?
.pkf files are generated by Adobe Audition, a professional audio editing application - originally introduced as peak cache files in Syntrillium Cool Edit during the 1990s and carried forward when Adobe acquired Syntrillium in 2003.
Contents of .pkf files
Files with the .pkf extension contain precomputed waveform peak data derived from audio sources such as WAV, MP3, AIF, or FLAC files. This data allows visualization of amplitude on a graph with time on the horizontal axis and sound amplitude on the vertical axis. Rather than re-scanning the full audio on every open, Audition stores arrays of minimum and maximum peak samples per zoom block so the waveform draws instantly. Each .pkf sidecar shares its base filename with the source audio - for example, song.wav and song.pkf sit side by side. Adobe Audition automatically generates .pkf files for audio tracks and new projects, so there is no need to recreate them on every import. Audition also validates each cache against the source file's path, size and timestamp, regenerating it automatically when the audio changes.
Can I delete a .pkf file?
.pkf files are created by Adobe Audition by default upon every audio file import. However, data in such a file is not always needed by users. A .pkf contains no audio - it is a disposable waveform-drawing cache, much like a thumbnail cache for images. Deleting it is completely safe; Audition rebuilds it the next time the audio file is opened. In large projects, accumulated .pkf files can occupy noticeable disk space, which is the most common reason to clear them.
Security & safety
RISK: LOWA .pkf is an inert cache with no audio and no executable content, so it poses no risk and is safe to delete - Adobe Audition rebuilds it on demand. The only practical issue is a stale/corrupt peak file showing a wrong waveform, fixed by deleting it or clearing Audition's peak cache. As always, be wary of files merely named ".pkf" from unrelated software (e.g. legacy ZoneAlarm policy files) if you didn't create them in Audition.
Format details
in a nutshell- TrueVector / ZoneAlarm policy file - Older ZoneAlarm (Zone Labs) firewall stored a true-vector security policy as .pkf; unrelated to audio.
- Pinnacle / Olympus media key file - Some Pinnacle Studio and Olympus dictation/imaging tools used .pkf for keys or peak/index data; unrelated to Audition.
Programs that open PKF files
Windows1 app
Adobe Audition
Paid You don't open the .pkf directly - open the matching audio file (.wav/.mp3) and Audition uses (or rebuilds) the peak cache automatically. 
macOS1 app
Adobe Audition
Paid Open the source audio file; Audition reads or regenerates the .pkf. The peak file itself is not meant to be opened standalone. Technical details
deep spec| File type | Binary waveform-peak cache - a sidecar companion to an audio file, not an audio format itself |
| Developer | Adobe Inc. (originally Syntrillium Software, creator of Cool Edit) |
| Encoding | Proprietary binary, little-endian byte order |
| Compression | None - stores precomputed min/max peak samples rather than compressed audio |
| Typical file size | A few KB to several MB, scaling proportionally with source audio length |
| Internal structure | Fixed proprietary header followed by arrays of minimum and maximum amplitude values per zoom block |
| MIME type | application/octet-stream |
| Sidecar naming convention | Shares the base filename of its audio source (e.g., `recording.wav` pairs with `recording.pkf`) |
| Cache validation | Verified against the source file's path, size and modification timestamp; auto-regenerated on any mismatch |
| Audio content | None - holds derived waveform peaks only; no PCM samples are stored |
| Magic bytes | No published stable signature; undocumented proprietary binary header with no fixed offset pattern |
| Compatible source formats | `.wav`, `.mp3`, `.aif`, `.flac`, `.cfa` and other formats importable into Adobe Audition |
| Supported platforms | Windows and macOS (wherever Adobe Audition runs) |
| Regeneration behavior | Rebuilt automatically by Audition when the file is missing, deleted, or invalidated by a source-file change |
| Origin | Introduced in Syntrillium Cool Edit (1990s); adopted under the Adobe Audition name after Adobe's 2003 acquisition of Syntrillium |
| Released | Cool Edit / Cool Edit Pro (1990s); carried into Adobe Audition after Adobe acquired Syntrillium (2003) |
| Latest version | Adobe Audition (Creative Cloud) - peak cache still used |
| Specification | helpx.adobe.com |
PKF conversions
Community Q&A
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