APE (Monkey's Audio) — Complete Format Guide
APE is a lossless audio compression format, commonly known as Monkey's Audio after the software that created it. APE files use the .ape extension and were once celebrated for achieving some of the highest compression ratios among lossless audio formats. Today, APE occupies a niche role: it is most commonly encountered in CUE+APE disc image rips from the early 2000s, and its use in new workflows has largely been superseded by FLAC.
History: Matthew T. Ashland and Monkey's Audio
APE was created by Matthew T. Ashland and first released in 2000 under the Monkey's Audio brand. The software and format were designed with one primary goal: maximum compression of lossless audio, squeezing music libraries into the smallest possible space at a time when hard drives were expensive and small.
The encoder and player were distributed as freeware for Windows. The source code was eventually released under a custom license that permitted non-commercial use but imposed restrictions on commercial redistribution — a "source available" model rather than a true open-source license. This licensing ambiguity caused significant friction with open-source projects and Linux distributions, many of which refused to ship APE support or shipped it only as an optional, separately compiled component.
Unlike FLAC, which was developed from the start as a fully open standard, APE has always operated under more restrictive terms, limiting its adoption in libre software ecosystems.
Compression Levels
One of APE's distinguishing features is its granular control over the compression-speed tradeoff. The encoder offers five compression levels:
| Level | Name | Relative Speed | Compression |
|---|---|---|---|
| 1000 | Fast | Very fast encode/decode | Lowest compression |
| 2000 | Normal | Moderate | Moderate compression |
| 3000 | High | Slower | High compression |
| 4000 | Extra High | Much slower | Very high compression |
| 5000 | Insane | Extremely slow | Maximum compression |
At Insane level, APE can achieve compression ratios that are 5–8% better than FLAC at its maximum setting. However, this comes at a severe cost: decoding becomes computationally intensive, sometimes requiring more CPU time than real-time playback on older hardware or embedded devices.
Why APE Is Controversial
APE's reputation in the audio community is mixed, primarily for three reasons:
1. Slow decoding at high compression levels. At Extra High and Insane levels, decoding an APE file requires substantially more CPU power than decoding FLAC. On smartphones, portable media players, and embedded streaming devices, this translates to increased battery drain and playback stuttering.
2. Limited ecosystem support. Because of the non-standard open-source license and the Windows-centric origins of Monkey's Audio, many platforms do not support APE natively. Android's native media framework, iOS, most smart TVs, and the vast majority of streaming infrastructure have no built-in APE support.
3. Fragility and seeking. APE's compression algorithm uses a highly stateful prediction model, meaning that the entire file must be read from the beginning to decode any given point. Seeking (jumping to a position in the middle of a song) is significantly slower than with FLAC or WAV. This also means that a single corrupted byte can render an entire APE file unplayable.
APE vs FLAC — Head-to-Head Comparison
| Feature | APE (.ape) | FLAC (.flac) |
|---|---|---|
| Compression ratio | Higher (5–8% better at max) | Very good |
| Decode speed | Slow at high levels | Fast at all levels |
| Seeking | Poor (stateful decoder) | Excellent |
| Corruption tolerance | Very low | Moderate |
| Mobile support | Almost none natively | Growing (Android, some iOS) |
| Streaming platforms | Not supported | Supported (Tidal, Qobuz) |
| Open source license | Restrictive custom license | Full open source (BSD) |
| Linux/NAS support | Limited (optional builds) | Native in virtually all distros |
| Software support | Windows-focused | Universal |
| Format age | 2000 | 2001 |
The consensus in the audio community is clear: unless you already have APE files, use FLAC. The compression advantage of APE does not justify its compatibility and performance penalties in modern contexts.
Converting APE to FLAC with FFmpeg
This is the most common and recommended conversion for APE files. Since both formats are lossless, no audio quality is lost:
# Single file: APE to FLAC
ffmpeg -i input.ape -c:a flac -compression_level 8 output.flac
# Preserve all metadata tags
ffmpeg -i input.ape -c:a flac -compression_level 8 -map_metadata 0 output.flac
# Batch convert all APE files in a directory
for f in *.ape; do ffmpeg -i "$f" -c:a flac -compression_level 8 "${f%.ape}.flac"; done
If ffmpeg reports an error reading the APE file, it is often due to an associated .cue file. See the CUE+APE section below.
Converting APE to MP3
# High quality VBR MP3 from APE
ffmpeg -i input.ape -c:a libmp3lame -q:a 2 output.mp3
# CBR 320 kbps MP3
ffmpeg -i input.ape -c:a libmp3lame -b:a 320k output.mp3
# Batch conversion
for f in *.ape; do ffmpeg -i "$f" -c:a libmp3lame -q:a 2 "${f%.ape}.mp3"; done
Converting APE to MP3 introduces lossy compression. Always retain the original APE or convert to a lossless intermediate (FLAC) first.
CUE+APE — The Classic Lossless CD Rip
Throughout the early 2000s, a common practice in the music-sharing community was to rip an entire CD into a single monolithic APE file accompanied by a CUE sheet (.cue). The CUE sheet acts as a table of contents, describing where each track starts and ends within the large APE file.
This pairing is commonly referred to as CUE+APE and is still frequently encountered when downloading classic album rips. To work with these files, you typically need to:
Option 1: Split into individual tracks using shntool or cuetools
# Split CUE+APE into individual FLAC tracks (requires shntool and flac)
shnsplit -f album.cue -t "%n - %t" -o flac album.ape
Option 2: Play the entire CUE+APE directly Players such as foobar2000 (Windows), DeaDBeeF (Linux), and VLC can parse the CUE sheet and present the APE as a multi-track album without splitting.
Option 3: Convert the monolithic APE to FLAC first, then split
ffmpeg -i album.ape -c:a flac album_full.flac
# Then split album_full.flac using the .cue file with shntool or cuetools
Problems Playing APE on Mobile Devices
APE playback on mobile devices is a persistent pain point:
- iOS: The native Music app and most iOS media frameworks do not support APE. Third-party apps like VLC for iOS, Flacbox, and Equalizer+ can play APE but with varying levels of reliability.
- Android: Android's native MediaPlayer API does not include APE support. Apps like Poweramp, VLC for Android, and Neutron Music Player add APE support via bundled decoders, but playback at Insane compression level can cause skipping on older devices.
- Streaming boxes / Smart TVs: Practically no consumer streaming device or smart TV platform supports APE natively. DLNA/UPnP servers that transcode on-the-fly (such as Plex) can work around this, but it adds CPU load on the server.
The practical solution for mobile playback is to convert your APE library to FLAC. The conversion is lossless, and FLAC is supported by virtually every modern media player, mobile app, and streaming service.
Summary
APE (Monkey's Audio) is a historically significant lossless audio format that pushed compression ratios beyond what was achievable with FLAC at the time of its release. Today, its advantages — slightly better compression at extreme settings — are outweighed by its drawbacks: slow decoding, poor mobile support, restrictive licensing, and fragility against data corruption. If you encounter APE files, especially in CUE+APE format from classic CD rips, converting them to FLAC with FFmpeg is the best path forward. FLAC provides nearly identical compression with superior speed, compatibility, and long-term viability.
Related conversions
Audio format pairs that come up most often: