Free online WAV to OPUS converter

A recording may need conversion when a messaging app, browser player, or storage workflow accepts Opus but not a large WAV file. Opus reduces the size for sharing and streaming, while the original WAV should remain available for editing or archival use.

What the WAV format is

WAV is an audio container developed by Microsoft and IBM that commonly stores uncompressed PCM samples. Recorders, digital audio workstations such as Audacity and Adobe Audition, game-development tools, and professional audio equipment use it because applications can edit the samples without first decoding a lossy format.

WAV preserves the source samples when it contains PCM, but the files are large. Uncompressed stereo PCM at 48 kHz and 24-bit uses about 2.2 MB per minute. WAV is therefore suited to recording, editing, mastering, and interchange, but less suited to web delivery or messaging when storage and bandwidth matter.

What the Opus format is

Opus is a lossy audio codec designed for speech, music, streaming, and real-time communication. Files using the .opus extension normally store Opus audio in an Ogg container.

Opus produces much smaller files than uncompressed WAV at practical listening quality. It supports mono and stereo audio, speech-focused bitrates, full-band music, variable bitrate encoding, and sample rates up to 48 kHz. WebRTC applications, many browsers, VLC, Discord, and many current phones support it, but older editors, hardware players, and legacy applications may not.

How to convert with FFmpeg

FFmpeg provides the most control and is suitable for batch conversion. Install FFmpeg, open a terminal or command prompt in the folder containing the WAV file, and run:

ffmpeg -i input.wav -c:a libopus -b:a 128k output.opus

This creates a 128 kbps Opus file and leaves input.wav unchanged. As starting points, use about 48k to 64k for mono speech, 96k for speech or modest-quality music, and 128k for general stereo music. Use 160k to 192k when retaining more music detail is preferable to minimizing size.

For a mono voice recording, specify one channel explicitly:

ffmpeg -i speech.wav -c:a libopus -ac 1 -b:a 48k speech.opus

FFmpeg normally selects an appropriate Opus sample rate automatically. Do not upsample a 44.1 or 48 kHz WAV before encoding; resampling cannot restore information absent from the recording.

How to convert with Audacity

1. Open the WAV file in Audacity with File → Open.
2. Choose File → Export Audio or the equivalent export command in your Audacity version.
3. Select Opus as the file type, choose a bitrate appropriate to speech or music, and set the output filename with the .opus extension.
4. Click Export and review any metadata options before saving.

Audacity is useful when you need to trim, normalize, or edit the recording before export. Menu labels and available Opus options can vary by version; FFmpeg is preferable for repeatable commands and batch jobs.

How to convert without installing software

You can convert the file on 101convert.com for free: upload the WAV file, select OPUS as the output format, start the conversion, and download the resulting file. Do not upload confidential recordings unless the service's privacy and retention terms are acceptable.

Quality and compatibility limits

Opus encoding is lossy. Converting the result back to WAV produces a PCM file but does not restore details discarded during encoding, so keep the original WAV for editing, mastering, or archival storage.

Bitrate and channel count have a greater effect on size and quality than the filename extension. Very low bitrates can create audible artifacts in stereo music, while speech generally remains intelligible at much lower bitrates. Encode directly from the original WAV rather than repeatedly converting between lossy formats.

Support for containers and metadata varies. Some applications accept Opus only in an Ogg container, while others expect the .opus extension; changing .ogg to .opus, or the reverse, does not convert the audio. Check the target application's requirements and verify tags, album art, and chapter information after conversion.