What is the PEAK file format?
A .peak file is a waveform display cache generated by Steinberg Cubase and Nuendo alongside audio files in a project. It stores pre-computed peak amplitude data - minimum and maximum sample values at multiple zoom resolutions for each channel - allowing Cubase to render waveform overviews instantly without re-reading the full audio file.
The .peak file is linked to its parent audio file by matching base name, stored in the same directory or an Images/ subfolder. It contains no audio data whatsoever; it is purely a rendering optimization. Deleting a .peak file is entirely safe - Cubase regenerates it automatically the next time the associated audio file is accessed. For this reason, .peak files are typically excluded from project backups and version control.
The format is binary and proprietary to Steinberg, with no documented magic bytes. Steinberg WaveLab uses a different cache format for the same purpose: .GPK. Adobe Soundbooth (discontinued 2011, succeeded by Adobe Audition) also used the .peak extension for its own distinct waveform cache structure, though that association is now obsolete.
File size scales with audio duration - roughly 1/500th the size of the corresponding .WAV or .AIF file. Multi-channel audio produces proportionally larger .peak files due to per-channel peak storage.
Security & safety
RISK: LOWPEAK files are auto-generated cache files with no executable code. Safe to delete (Cubase regenerates them). No security concerns.
Format details
in a nutshell- Adobe Soundbooth Peak Data File - Adobe Soundbooth (EOL 2011, replaced by Adobe Audition) generated .peak waveform cache files alongside audio projects; different binary structure from Cubase's .peak.
Programs that open PEAK files
Windows2 apps
Cubase
Paid PEAK files are used automatically by Cubase; no manual action needed. Open the associated Cubase project to view the waveforms. 
Nuendo
Paid Steinberg Nuendo (professional post-production DAW) uses the same .peak cache format as Cubase. 
macOS1 app
Technical details
deep spec| File purpose | Waveform display cache - stores amplitude peak data, not audio |
| Encoding | Binary proprietary (Steinberg) |
| Byte order | Little-endian (Windows); big-endian possible on legacy macOS builds |
| Typical file size | 1 KB - 2 MB (approximately 1/500th of the parent audio file size) |
| Channel support | Per-channel peak storage (stereo and multi-channel) |
| Zoom resolutions | Multiple pre-computed resolutions for instant waveform rendering at any zoom level |
| File linking | Matched by base filename to parent audio (same directory or Images/ subfolder) |
| Regeneration | Auto-recreated by Cubase if deleted; safe to remove |
| Associated platform | Windows and macOS |
| Related Steinberg format | WaveLab uses .gpk for an equivalent waveform cache |
| Adobe Soundbooth overlap | Soundbooth (EOL 2011) used .peak for a distinct, incompatible cache structure |
| Audio data present | None - file holds only amplitude envelope metadata |
| Released | Cubase 4 era (mid-2000s) for Cubase's waveform overview cache |
| Latest version | N/A (internal cache format, no versioning exposed to users) |
PEAK conversions
Community Q&A
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