Free online AIFF to SPX converter

Source format: AIFF

AIFF (Audio Interchange File Format) is an uncompressed audio container developed by Apple. It is widely used in professional audio production, especially on macOS systems, for storing high-quality master recordings, edited tracks, and sound assets. Because AIFF typically preserves audio without lossy compression, it is valued for editing, archiving, and interchange between audio tools.

Target format: SPX

SPX usually refers to audio encoded with the Speex codec and stored in an Ogg container. It is designed for speech compression, offering much smaller file sizes than uncompressed audio while keeping voice intelligible. SPX is commonly used for voice recordings, VoIP-related audio, and speech archives where bandwidth and storage efficiency matter more than full-fidelity music reproduction.

How to perform the conversion

The most reliable way to convert AIFF to SPX is with FFmpeg, a widely used command-line multimedia tool. This is especially useful because it can read AIFF directly and encode to Speex-compatible output.

1. Install FFmpeg on your computer if it is not already available.
2. Open a terminal or command prompt in the folder containing your AIFF file.
3. Run a command such as ffmpeg -i input.aiff -c:a libspeex output.spx.
4. If needed, adjust the speech quality with options such as -ar 16000 for a common narrowband speech rate or -ab 16k for bitrate control, depending on your source and compatibility needs.
5. Test the resulting output.spx in a player or editor that supports Speex/Ogg audio.

If you prefer a simpler workflow, you can also convert the file on 101convert.com for free without installing any software.

Quality and compatibility notes

AIFF is usually much larger than SPX, so the conversion will significantly reduce file size. However, Speex is optimized for speech, not music, so converting songs or complex audio from AIFF to SPX will usually reduce quality noticeably. For best results, use SPX only when the source is primarily spoken voice.

Compatibility can also vary: some apps recognize SPX files only when they are stored in an Ogg container, while others may expect a different extension or may not support Speex at all. If playback fails, try a player with broader codec support or verify that the output was encoded correctly. For archival or editing purposes, keep the original AIFF file because SPX is a lossy format and is not ideal for repeated re-encoding.