Free online MP3 to OMA converter

Older Sony Network Walkman players and SonicStage libraries may require Sony’s OpenMG audio files instead of ordinary MP3 files. This conversion is mainly needed to load music onto compatible legacy Sony hardware; current phones and players generally accept MP3 directly.

What the MP3 format is

MP3 is MPEG-1 or MPEG-2 Audio Layer III, a lossy audio format identified by the .mp3 extension. Computers, phones, car stereos, portable players, media servers, VLC, Windows Media Player, iTunes, and audio editors widely support it.

MP3 compresses audio at a selected bitrate, commonly 128, 192, 256, or 320 kbps. It is used for portable playback and distribution because its files are much smaller than uncompressed audio.

What the OMA format is

OMA is Sony’s OpenMG audio file format, usually identified by the .oma extension. SonicStage and older Sony Network Walkman and Net MD workflows commonly used OMA files containing ATRAC3, ATRAC3plus, or another Sony ATRAC-family codec.

Some OMA files also contain OpenMG digital rights management or Sony-specific metadata. DRM-enabled files can be tied to the SonicStage installation, user account, or device that created them. OMA is therefore not a broadly interchangeable replacement for MP3, and many current applications cannot play it.

How to create OMA files

Use SonicStage for compatible Sony devices

1. Install a SonicStage release and its required OpenMG or ATRAC components on a supported Windows system. SonicStage is discontinued; use original Sony installation media or a legally obtained archive, verify the files, and avoid modified installers.
2. Open SonicStage and import the MP3 files through File → Import or the library’s import command.
3. In the library or transfer settings, select the option named Convert Format, ATRAC conversion, or similar, if available. Choose ATRAC3 or ATRAC3plus and a bitrate supported by the specific Walkman. Device models do not all support the same ATRAC profiles.
4. Connect the Sony player and transfer the tracks through SonicStage. The program normally creates the OpenMG/OMA representation during library conversion or device transfer rather than acting as a modern standalone OMA encoder.
5. If SonicStage offers a setting to retain converted files in its library, enable it and record the storage location. Do not rename track.mp3 to track.oma; an extension change does not change the codec, file structure, or DRM.

Some older Sony Sound Forge releases and licensed ATRAC encoders can create ATRAC audio, but an ATRAC-encoded file is not necessarily a device-valid OpenMG OMA file. Use these tools only when the target software explicitly accepts their output.

When SonicStage is unavailable

No reputable online converter can reliably produce a valid, device-compatible OpenMG OMA file. Services claiming OMA conversion may only rename the extension, produce an unsupported ATRAC variant, or omit the OpenMG metadata and DRM expected by SonicStage or the player. Do not upload private or copyrighted recordings to such services.

If the Sony device accepts MP3, transfer the original files instead. If it accepts another documented format, use a current desktop converter such as FFmpeg or VLC; that will not create OMA. For example, FFmpeg can create an AAC file with ffmpeg -i input.mp3 -c:a aac -b:a 192k output.m4a, but the device’s documentation should determine the output format.

Quality and compatibility limits

Converting MP3 to ATRAC is a second lossy encoding step. It cannot restore detail discarded during the original MP3 encoding, and converting a low-bitrate MP3 to a higher-bitrate OMA file increases its size without improving sound quality. Keep the original MP3 and use the highest practical source quality.

OpenMG DRM may restrict playback, copying, or transfer to the computer and device that created the file. SonicStage may also require obsolete drivers, compatibility settings, and model-specific transfer support. Test one short track and one device transfer before converting a complete library.