Free online OPUS to SRT converter

Source format: Opus

Opus is a modern, highly efficient audio codec commonly stored in files with the .opus extension, often inside an Ogg container. It is widely used for voice recordings, online calls, streaming audio, and other speech-focused or low-latency audio applications. Opus is popular because it delivers good sound quality at relatively small file sizes and works well across a wide range of bitrates.

Target format: SRT

SRT is a plain-text subtitle format used to store timed captions for video and audio content. Each subtitle entry contains a sequence number, start and end timestamps, and the subtitle text. SRT is widely supported by media players, video editors, and subtitle tools because it is simple, human-readable, and easy to edit. Its main advantage is broad compatibility rather than advanced styling.

How to perform the conversion

It is important to note that Opus audio cannot be directly converted to SRT in the usual sense, because SRT is not an audio format. To create an SRT file from an Opus recording, you must first transcribe the speech and then save the transcript with timestamps as subtitles.

Best workflow:

1. Open the .opus file in a transcription tool or speech-to-text application.
2. Generate a transcript with timestamps, preferably at the sentence or phrase level.
3. Review and correct the text for names, punctuation, and timing.
4. Export or save the result as .srt.

Common desktop tools:

• Subtitle Edit can import audio, create subtitles from speech recognition, and export to SRT.
• Aegisub is useful for manual subtitle timing and editing after transcription.
• Whisper-based tools can transcribe Opus audio and produce subtitle files, including SRT, depending on the interface used.

Example with Subtitle Edit:

1. Launch Subtitle Edit.
2. Choose File → Open and select the .opus file, or open it through the audio waveform workflow.
3. Use the speech recognition or transcription feature to generate subtitle text.
4. Adjust timing if needed.
5. Choose File → Save as and select .srt.

Example with Whisper-based transcription:

1. Run a transcription tool that supports Opus input.
2. Transcribe the audio to timed segments.
3. Export the transcript as .srt if the tool supports subtitle output.

If you want a quick browser-based workflow, you can convert the file on 101convert.com for free without installing any software, then review the generated subtitles carefully.

Notes on quality and limitations

Direct conversion is not possible because Opus contains audio data and SRT contains subtitle text. The quality of the resulting SRT depends on the accuracy of speech recognition and the clarity of the recording. Background noise, overlapping speakers, accents, and low volume can reduce transcription quality. Automatic timestamps may also need manual correction to make subtitles readable and properly synchronized.

For best results, use a clean recording, verify the transcript, and split long subtitle lines into short, readable captions. If the Opus file contains music only or no speech, an SRT file cannot be meaningfully generated without manual captioning.