Free online AIFF to AT3 converter

What the AIFF format is

AIFF, or Audio Interchange File Format, is an Apple-developed container commonly used for uncompressed PCM recordings. It preserves the source waveform accurately but produces large files, typically at 44.1 or 48 kHz with 16- or 24-bit samples. Apple Logic Pro, GarageBand, Audacity, Adobe Audition, Pro Tools, and many other recording applications can create or export AIFF files.

What the AT3 format is

In the Audio category, AT3 normally means audio encoded with Sony ATRAC3, a lossy compression format used by SonicStage, some MiniDisc-related software, Sony portable devices, and the PlayStation Portable. ATRAC3 files are much smaller than equivalent AIFF files, with common bitrates including 66, 105, 132, and 256 kbps.

AT3 is not as broadly supported as MP3, AAC, or WAV. Some Sony software expects ATRAC3 inside a particular RIFF or OMA-based container, so a file with an .at3 extension is not automatically compatible with every Sony device.

How to convert AIFF to AT3

The built-in converter at 101convert.com can perform the conversion without installing software:

1. Open 101convert.com and choose the audio conversion tool.
2. Upload the .aiff or .aif file.
3. Set the output format to AT3 or ATRAC3.
4. Select the bitrate or device preset if the converter provides those options. Use the bitrate required by the destination Sony application or device.
5. Start the conversion and download the generated .at3 file.

For desktop conversion, use an audio editor or converter that explicitly lists a Sony ATRAC3 encoder. Open the AIFF, choose File → Export or File → Save as, select ATRAC3/AT3, set the required bitrate and sample rate, then export. A standard WAV or MP3 exporter cannot create a valid AT3 file merely by changing the filename extension.

Quality and compatibility limitations

AIFF is often lossless, while ATRAC3 is lossy. Converting an AIFF to AT3 discards audio information; converting the AT3 back to AIFF only decodes the compressed result and cannot restore the original quality. Keep the AIFF as the archival master.

Use a 44.1 kHz source when the target software or device requires it, and avoid unnecessary sample-rate conversion. Test the output in the exact Sony application or hardware that will use it. If it rejects the file, the problem may be the required container, metadata, naming convention, or device-specific ATRAC3 profile rather than the audio data itself.