Free online TXT to OPUS converter

A device or app that accepts spoken audio but not a script may require a TXT file to be rendered as an OPUS recording. The conversion uses text-to-speech; a TXT file does not contain audio to encode.

What the TXT format is

TXT is plain text without audio, layout, or playback data. It is commonly created with Notepad, TextEdit, code editors, and word processors when saving as plain text, and is used for scripts, notes, and transcripts. For speech synthesis, the words and punctuation in the file determine what is read aloud.

What the OPUS format is

Opus is a lossy audio codec designed for speech and music at low bit rates. Files with the .opus extension typically store Opus audio in an Ogg container. It is useful for compact voice recordings, but compatibility can be weaker in older players than with WAV or MP3.

How to convert TXT to OPUS

Online on 101convert.com

1. Upload the TXT file on the converter page. Multiple files can be added as a batch; the page shows the per-file size limit.
2. Set the voice language and reading speed before converting.
3. Convert the file, then download the resulting OPUS audio.

Offline with desktop software

On Windows, macOS, and Linux, use the open-source eSpeak NG to synthesize speech and FFmpeg to encode it as Opus. Install both programs, then run these commands in a terminal from the folder containing script.txt:

1. espeak-ng -v en-us -s 160 -f script.txt -w speech.wav creates a WAV file. Replace en-us with an installed voice language and adjust -s 160 to change the speaking rate.
2. ffmpeg -i speech.wav -c:a libopus -b:a 32k speech.opus encodes the synthesized speech as Opus. The FFmpeg build must include the libopus encoder.

Quality and compatibility

This process synthesizes a voice rather than converting existing audio; pronunciation and pacing depend on the selected speech engine, voice, and source punctuation. Opus encoding is lossy, so retain the TXT source if you may need to regenerate the recording with different speech settings.