Free online ODT to M4A converter

If a phone, car stereo, or audio player needs a spoken version of a document, an ODT file must be converted into audio rather than simply renamed. The result is a read-aloud M4A file that can be played without opening a word processor.

What the ODT format is

ODT (OpenDocument Text) is an editable word-processing format used for letters, reports, and other documents. LibreOffice Writer and Apache OpenOffice create ODT files; Microsoft Word and other office programs can also open or save them. ODT stores formatted text and document structure, not recorded sound.

What the M4A format is

M4A is an audio file extension commonly used for MPEG-4 audio encoded with AAC. It is supported by many phones, computers, media players, and car stereos. AAC audio is generally smaller than uncompressed WAV at comparable listening quality, making M4A useful for storing or sharing spoken audio.

How to convert ODT to M4A

This conversion uses text-to-speech (TTS): the document’s text is spoken by a synthetic voice and saved as audio. It does not turn the page layout into sound.

Online on 101convert.com

1. Upload the ODT file to the converter on the page. Multiple files can be added for batch conversion; check the page for its per-file size limit.
2. Before converting, choose the voice language and reading speed.
3. Start the conversion, then download the M4A file.

Offline with desktop software

For an offline workflow, use LibreOffice to extract plain text, eSpeak NG to synthesize speech, and FFmpeg to encode M4A. These programs are available for Linux, macOS, and Windows; install them first and make sure their command-line tools are available. The following commands use a POSIX shell, such as Terminal on Linux or macOS. Replace input.odt with your filename:

1. Create an output folder and export the document as plain text: mkdir -p work, then soffice --headless --convert-to txt:Text --outdir work input.odt. LibreOffice creates work/input.txt.
2. Generate a speech recording: espeak-ng -f work/input.txt -w work/speech.wav.
3. Encode the recording as AAC audio in an M4A container: ffmpeg -i work/speech.wav -c:a aac -b:a 128k output.m4a.

On Windows, run the equivalent commands in PowerShell or Command Prompt, using the installed executable paths if soffice, espeak-ng, or ffmpeg is not on your PATH.

Quality and limitations

The output is synthesized speech, so voice quality and pronunciation depend on the TTS voice and selected language. Tables, page layout, images, and visual emphasis do not carry over as such; exported text may also read headings or table cells in an order that differs from the page layout. In the offline commands, -b:a 128k sets the AAC bitrate: a higher bitrate increases file size, while speech often remains intelligible at lower rates.