What is the PEK file format?
.pek is a waveform cache sidecar file created by Adobe Premiere Pro (and Adobe After Effects) alongside imported audio clips. It stores pre-computed peak amplitude data - the minimum and maximum sample values across short time intervals at multiple zoom levels - so the audio waveform display in the timeline renders instantly without re-scanning the source media each time.
PEK files are saved either next to the source media or in the Premiere Pro media cache folder, configured under Preferences > Media Cache. Their companion format is .cfa (Conforming Audio), a normalized PCM copy of the source audio. Both sidecar types are generated automatically when media is first imported and are regenerated automatically if deleted, making it safe to remove them to free disk space or resolve waveform display errors.
The internal format is proprietary binary, undocumented, and tied to the version of Premiere Pro that created it. File size scales with clip length and channel count. Deleting .pek files (along with .cfa) is the standard fix for the "generating peak file" slowdown that appears after moving or reconnecting media.
PEK files have no value outside Premiere Pro or After Effects and should be excluded from project archives and version control systems.
Security & safety
RISK: LOWPEK is a passive binary cache - it executes no code and poses no security risk. Some fake 'PEK opener/converter' download pages bundle PUP/adware - there is nothing to open or convert; ignore such offers entirely.
Format details
in a nutshell- Pek Game Data Archive - A completely unrelated game data container format used by some older games; rare.
Programs that open PEK files
Windows2 apps
Adobe Premiere Pro
Paid PEK files are read automatically by Premiere Pro - no manual open action needed. Delete to regenerate. 
macOS2 apps
Adobe Premiere Pro
Paid PEK files managed automatically. Preferences > Media Cache > Clean allows bulk deletion. Technical details
deep spec| File role | Sidecar waveform cache - pre-computed audio peak data for instant timeline waveform rendering |
| Data stored | Min/max amplitude envelope samples at multiple zoom levels (mipmapped peak data) for fast multi-resolution display |
| Companion format | `.cfa` (Conforming Audio) - normalized PCM copy of source audio; both generated together on media import |
| Storage location | Alongside source media, or in the Premiere Pro media cache folder (**Preferences > Media Cache**) |
| Format | Proprietary binary; structure is undocumented and version-specific to the Premiere Pro release |
| Regeneration behavior | Auto-regenerated by Premiere Pro or After Effects if missing, corrupt, or deleted - safe to remove |
| Platform | Windows and macOS (wherever Adobe Premiere Pro or After Effects is installed) |
| Compression | None - raw amplitude values stored for maximum read speed during timeline scrubbing |
| Typical file size | 10 KB - 5 MB, proportional to clip length and channel count |
| Common troubleshooting use | Deleting `.pek` and `.cfa` files resolves "generating peak file" slowdowns after media reconnects |
| After Effects | Adobe After Effects also generates `.pek` sidecar files when working with audio clips |
| Portability | Not portable between machines or Premiere versions; should be excluded from project archives and VCS |
| Released | circa 2003 (Adobe Premiere Pro 1.0) |
| Latest version | N/A (internal cache format, no versioning published) |
| Specification | helpx.adobe.com |
PEK conversions
Community Q&A
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