Convert 3G2 to WEBA — Free Online Tool
Convert 3G2 mobile video files to WEBA audio by extracting and re-encoding the audio stream to Opus format, discarding the video entirely. This is ideal for pulling audio content from old CDMA-era mobile clips and delivering it as a modern, web-optimized Opus audio file.
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FFmpeg Command
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Note: Browser-based encoding uses approximate quality targets. For precise CRF compression, copy the FFmpeg command above and run it on your desktop.
Estimated output:
Conversion Complete!
DownloadHow It Works
3G2 is a multimedia container developed for CDMA mobile networks (used by carriers like Verizon and Sprint), typically holding H.264 video and AAC audio. WEBA is an audio-only WebM container, and this conversion strips the video stream completely while transcoding the AAC audio from the 3G2 file into Opus, using the libopus encoder. Opus is a modern, highly efficient lossy codec standardized by the IETF, offering better audio quality at equivalent bitrates compared to the AAC found in most 3G2 files. Because the audio must be decoded from AAC and re-encoded into Opus, this is a full transcode — not a remux — meaning a small amount of generation loss occurs, though at 128k Opus the result is perceptually transparent for most audio content.
What Each Flag Does
| Flag | What it does |
|---|---|
ffmpeg
|
Invokes the FFmpeg program, the open-source multimedia processing engine that handles decoding the 3G2 container and re-encoding its audio stream into the WEBA output format. |
-i input.3g2
|
Specifies the input file — a 3G2 container typically holding H.264 video and AAC audio encoded for CDMA mobile transmission. FFmpeg reads both the video and audio streams from this file before applying the output options. |
-c:a libopus
|
Sets the audio encoder to libopus, which encodes the decoded AAC audio from the 3G2 file into the Opus codec format required by the WEBA container. Opus is the default and recommended codec for WEBA files, offering excellent quality at low bitrates. |
-b:a 128k
|
Sets the target audio bitrate to 128 kilobits per second for the Opus encoder. At this bitrate, Opus delivers high perceptual quality for both speech and music content, and generally matches or exceeds the quality of the original AAC audio found in most 3G2 files. |
-vn
|
Disables video output entirely, instructing FFmpeg to ignore the H.264 video track from the 3G2 file. This flag is required because WEBA is an audio-only container — and even if it weren't, WebM does not support H.264 video, so the video stream cannot be carried over in any case. |
output.weba
|
Specifies the output filename with the .weba extension, which tells FFmpeg to wrap the Opus audio stream in a WebM (audio-only) container. The .weba extension signals to browsers and media players that this is an audio-only WebM file suitable for direct playback via HTML5 audio elements. |
Common Use Cases
- Extracting the audio from old mobile video clips recorded on CDMA phones (e.g., early Verizon or Sprint handsets) to archive just the spoken content or ambient sound.
- Pulling audio from 3G2 video messages or MMS-era clips to embed as playable audio on a modern web page using the HTML5 <audio> element, which natively supports WEBA/Opus.
- Converting a 3G2 field recording or voice memo to Opus for use in a web-based audio player where WEBA is preferred for its low-latency streaming characteristics.
- Reducing file size by discarding the low-resolution video track of a 3G2 clip and retaining only the audio for podcast production or transcription workflows.
- Migrating an archive of 3G2 mobile recordings to a modern, royalty-free audio format (Opus/WebM) for long-term storage and browser-compatible playback without plugins.
- Extracting audio from a 3G2 video to use as a sound effect or voice clip in a web-based game or interactive application that requires the WebM/Opus format.
Frequently Asked Questions
Yes, a small amount of quality loss occurs because this conversion involves decoding the AAC audio from the 3G2 file and re-encoding it into Opus — a lossy-to-lossy transcode. However, at the default bitrate of 128k, Opus is widely regarded as audibly superior to AAC at the same bitrate, so the output may actually sound better or comparable to the original, especially for speech-heavy content. For critical audio, you can increase the output bitrate to 192k or 256k to minimize any perceptible degradation.
The video track is completely discarded. The -vn flag in the FFmpeg command explicitly tells FFmpeg to exclude all video streams from the output. WEBA is a strictly audio-only container format (a WebM variant), so it cannot store video data regardless. The result is a pure audio file containing only the re-encoded Opus audio from the original 3G2 clip.
WEBA is simply an audio-only WebM file — the .weba extension is a convention used to signal that a WebM container holds only audio (typically Opus or Vorbis), with no video track. Browsers like Chrome and Firefox treat .weba files the same as audio-only .webm files. The Opus codec inside is identical in both cases; the extension just helps applications and web servers identify the file as audio-only content more easily.
Yes, 3G2 files can technically contain AMR (Adaptive Multi-Rate) audio, which was common in very early mobile devices, or MP3 audio in some implementations. Regardless of the source audio codec in the 3G2 file, FFmpeg will decode it and re-encode it to Opus for the WEBA output — the command works the same way. If your 3G2 file uses AMR audio, the quality of the Opus output at 128k will still be good, though AMR source material is typically narrowband (optimized for voice) and will reflect those original quality limitations.
Replace the 128k value in the -b:a 128k flag with your desired bitrate. For example, use -b:a 192k for higher quality or -b:a 64k for a smaller file size. Opus is particularly efficient at low bitrates — even 64k Opus typically sounds better than 128k MP3 for voice content — but for music or complex audio from 3G2 clips, 128k to 192k is a safe range. The full command with 192k would be: ffmpeg -i input.3g2 -c:a libopus -b:a 192k -vn output.weba
On Linux or macOS, you can use a shell loop: for f in *.3g2; do ffmpeg -i "$f" -c:a libopus -b:a 128k -vn "${f%.3g2}.weba"; done. On Windows Command Prompt, use: for %f in (*.3g2) do ffmpeg -i "%f" -c:a libopus -b:a 128k -vn "%~nf.weba". This is especially useful when migrating a large archive of 3G2 mobile recordings, since the browser-based tool handles one file at a time.
Technical Notes
3G2 files use the ISO Base Media File Format (like MP4 and MOV), so FFmpeg reads them reliably without compatibility issues. The audio stream in most 3G2 files is AAC-LC at low bitrates (often 48k–128k), reflecting the bandwidth constraints of early CDMA networks. When transcoding to Opus via libopus, FFmpeg internally decodes the AAC to PCM and then encodes to Opus — any metadata embedded in the 3G2 container (such as title or artist tags) is not automatically carried over to the WEBA output, since WebM has a different metadata system (Matroska tags). If metadata preservation matters, you would need to add explicit -metadata flags to the command. WEBA/Opus does not support chapters or subtitle tracks, but 3G2 doesn't support these either, so nothing is lost in that regard. One important limitation: some very old 3G2 files encoded with AMR-NB audio are sampled at 8kHz (narrowband telephone quality); Opus will faithfully encode this content but cannot recover the frequency information that was never captured. The -vn flag is essential here and not optional — omitting it would cause FFmpeg to attempt to include the video stream, which would fail since WebM containers require VP8/VP9/AV1 video codecs, not the H.264 typically found in 3G2 files.