Free online OPUS to ODT converter

OPUS files contain recorded speech, while ODT files contain editable documents, so this task is a speech-to-text transcription rather than a simple format change. Convert the audio to text with a transcription tool, then save the result as an ODT document for editing, sharing, or archiving.

What the OPUS format is

OPUS is a compressed audio format designed for speech and music, commonly used by web browsers, voice recorders, messaging applications, VoIP systems, and services such as Discord. An .opus file may contain a voice message, meeting recording, interview, or other spoken audio. It stores sound, not document characters, so changing the extension to .odt cannot produce readable text.

What the ODT format is

ODT, or OpenDocument Text, is an editable word-processing format used by LibreOffice Writer, Apache OpenOffice, and other OpenDocument-compatible applications. It supports paragraphs, headings, tables, styles, images, comments, and basic page layout. ODT is useful when the transcription must be corrected, formatted, searched, printed, or exchanged without depending on a proprietary word-processing format.

How to convert OPUS to ODT

The conversion has two stages: transcribe the OPUS recording and save the resulting transcript as an ODT file.

Convert using 101convert.com

1. Open the OPUS-to-ODT converter on 101convert.com; the service can be used for free without installing software.
2. Upload the .opus file.
3. Select the spoken language if the converter provides a language option. Correct language selection improves recognition accuracy.
4. Start the conversion and wait for the transcription to finish.
5. Download the generated .odt file and open it in LibreOffice Writer or another ODT-compatible editor.

Convert locally with Whisper and LibreOffice

For local processing, OpenAI Whisper can transcribe the recording without uploading it to a conversion website. Install FFmpeg and Whisper, then run:

whisper recording.opus --model medium --language English --output_format txt

Replace recording.opus and the language value as needed. The command creates a plain-text transcript, usually named recording.txt. Open that file in LibreOffice Writer, correct names and punctuation, apply headings or other styles, then choose File → Save As, select ODF Text Document (.odt), and save.

FFmpeg can create a compatible WAV intermediate file when a transcription program has trouble reading OPUS:

ffmpeg -i recording.opus -ar 16000 -ac 1 recording.wav

Transcribe recording.wav instead of the original file. This changes the audio sampling format but does not improve recognition by itself.

Quality and compatibility limits

ODT stores the recognized words, not the original audio, speaker tone, or recording quality. Transcription accuracy depends on background noise, microphone quality, overlapping speakers, accents, vocabulary, and language selection. Review names, numbers, technical terms, and punctuation manually.

Most automatic transcriptions do not reliably identify speakers unless diarization is enabled separately. If speaker labels or timing matter, retain the original OPUS file and preserve any generated timestamped transcript alongside the ODT document. An ODT file may contain the transcript and formatting, but it will not necessarily preserve word-level timestamps or synchronized playback.