What is the OMA file format?
.oma is an audio format developed by Sony as part of its OpenMG digital rights management system. It is an implementation of the ATRAC audio compression standard, which offers Audio CD quality at significantly smaller file sizes. OMA files were used as the primary audio encoding for Sony Walkman devices and digital downloads from the Sony Connect Music Store. The Connect platform closed in 2008.
The .oma container uses a Sony-proprietary EA3 header - a variant of ID3v2 that begins with the ASCII string ea3 - wrapping ATRAC3 or ATRAC3plus audio frames. Some files carry an MP3 or WMA payload instead. The format offered built-in playback and copy-protection mechanisms (DRM) tied to a specific device or account; OMA audio files were distributed through the Sony Connect Music Store and managed via SonicStage software.
DRM-locked .oma files cannot be played on unauthorized devices. DRM-free files (from device recordings or certain transfers) can be decoded by VLC and fre:ac. Sony Music Center for PC partially replaced SonicStage, but .oma is effectively a legacy format - superseded by MP3 and AAC for general audio and by ATRAC9 (.at9) on newer Sony hardware such as the PlayStation Vita.
Security & safety
RISK: LOWOMA is a passive audio container; opening it for playback is safe. The DRM mechanism ties files to authorized Sony hardware - no exploit surface for typical users. Do not download OMA files from untrusted sources pretending to offer Sony music, as they may be malware wrapped in an unusual extension.
Format details
in a nutshellPrograms that open OMA files
Windows3 apps
VLC media player
Open-source File > Open File - plays unencrypted OMA/ATRAC3 files directly. DRM-locked files will not play. 
fre:ac (free audio converter)
Open-source Add OMA file to queue; supports ATRAC3 input and can convert to MP3/AAC/FLAC. Requires unencrypted files.
Sony Music Center for PC
Free Sony's current PC software for managing Walkman devices; provides OMA/ATRAC playback from Sony library. Limited usefulness for DRM files from the closed Connect Store. 
macOS1 app
VLC media player
Open-source File > Open - plays unencrypted OMA files. DRM-encrypted files will fail. 
Linux1 app
VLC media player
Open-source Opens unencrypted OMA/ATRAC3 files. FFmpeg backend required (usually included). 
Android1 app
VLC media player for Android
Open-source Can play unencrypted OMA files; tap to open from a file manager. Technical details
deep spec| Container format | EA3 header (Sony-proprietary ID3v2 variant beginning with `ea3`) wrapping ATRAC3/ATRAC3plus audio frames |
| Magic bytes | `65 61 33` ("ea3") at offset 0, followed by version bytes `03 00 00 00` |
| Byte order | Big-endian |
| Primary codec | ATRAC3 (66/105/132 kbps) or ATRAC3plus (32-352 kbps); occasionally MP3 or WMA payload |
| Sample rate | 44,100 Hz (standard for all ATRAC3/ATRAC3plus tracks) |
| DRM system | OpenMG DRM (AES-based); encrypted files are tied to a specific device/account |
| Typical file size | 2 MB - 15 MB per track depending on codec, bitrate, and track length |
| Distribution platform | Sony Connect Music Store (2004-2008); managed via SonicStage software on Windows |
| ATRAC3 frame structure | 512 or 1024 audio samples per sound unit depending on ATRAC variant |
| Supported devices | Sony Walkman (various models), PlayStation Portable (PSP), PlayStation 3 |
| Metadata | EA3 header carries title, artist, album, and DRM key reference (ID3v2-compatible field structure) |
| Unencrypted playback | DRM-free `.oma` files can be decoded by FFmpeg, VLC, and fre:ac; encrypted files require DRM removal |
| Legacy status | Connect Music Store closed 2008; SonicStage discontinued; superseded by ATRAC9 (`.at9`) on newer Sony hardware |
| Released | 1999 (Sony OpenMG system, MagicGate / ATRAC3) |
| Latest version | N/A - legacy format; no active spec development |
| Specification | wiki.multimedia.cx |
OMA conversions
Community Q&A
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