Extract Audio from 3G2 to WEBA — Free Online Tool
Extract audio from 3G2 mobile video files and convert it to WEBA format, re-encoding the AAC or MP3 audio stream using the Opus codec for efficient, web-optimized playback. Opus offers superior audio quality at low bitrates compared to the AAC typically found in 3G2 files, making this ideal for repurposing mobile video audio for web delivery.
to
FFmpeg Command
Copy this command to run the same conversion locally with FFmpeg on your desktop. Download FFmpeg
Drop your 3G2 file here
or click to browse
Free — no uploads, no signups. Your files never leave your browser.
Settings
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 files were designed for CDMA mobile networks (used by carriers like Verizon and Sprint) and typically contain AAC or MP3 audio paired with H.264 video. This tool strips the video stream entirely and re-encodes the audio track using the Opus codec, packaging it into a WEBA container (an audio-only variant of WebM). Because 3G2 uses AAC audio and WEBA requires Opus or Vorbis, a full audio transcode is necessary — the audio is decoded from AAC and re-encoded to Opus at your chosen bitrate. The resulting WEBA file is a lightweight, web-native audio format with no video data.
What Each Flag Does
| Flag | What it does |
|---|---|
ffmpeg
|
Invokes the FFmpeg tool. In this browser-based implementation, FFmpeg runs as a WebAssembly (WASM) binary entirely within your browser — no data leaves your device. |
-i input.3g2
|
Specifies the input 3G2 file. FFmpeg reads the MP4-derived container structure of the 3G2 file and identifies its audio track (typically AAC) and video track (typically H.264) for processing. |
-vn
|
Disables video output, telling FFmpeg to ignore the H.264 or MJPEG video stream from the 3G2 file entirely. This is what makes the output audio-only, since WEBA is a strictly audio container. |
-c:a libopus
|
Specifies the Opus encoder for the audio stream. Since 3G2 uses AAC and WEBA requires Opus or Vorbis, the audio must be fully transcoded — libopus decodes the incoming AAC and encodes it as Opus for the WEBA container. |
-b:a 128k
|
Sets the target audio bitrate to 128 kilobits per second for the Opus encoder. At this bitrate, Opus produces transparent or near-transparent quality for most audio content, and the resulting file will be significantly smaller than the original 3G2 due to Opus's superior compression efficiency. |
-vn
|
A second instance of the video-disable flag applied to the output side of the command. While redundant alongside the earlier -vn, it reinforces that no video stream should be written into the WEBA output file and is harmlessly ignored by FFmpeg. |
output.weba
|
Defines the output filename with the .weba extension, which FFmpeg uses to automatically select the WebM container format in audio-only mode. The .weba extension also signals to browsers and media players that this is an Opus audio file rather than a video WebM. |
Common Use Cases
- Extracting voice memos or audio recordings captured on older CDMA phones (Verizon/Sprint era) for use in web-based media players
- Repurposing audio from 3G2 video clips for embedding in web pages, where WEBA/Opus provides better compression than the original AAC at equivalent quality
- Archiving the audio content from legacy 3G2 mobile videos into a modern, open-standard format before the original files become unplayable
- Converting recorded phone call audio or voicemails stored in 3G2 format into web-friendly WEBA files for a browser-based communication platform
- Preparing audio from 3G2 sports or event clips captured on CDMA devices for streaming in a WebRTC or browser-based application where Opus is the native codec
- Extracting background music or ambient audio from 3G2 home videos to use as audio assets in a web project
Frequently Asked Questions
Yes, there is a generation loss because this conversion decodes the AAC audio from the 3G2 file and re-encodes it to Opus — two lossy compression stages in sequence. However, Opus is a highly efficient modern codec, and at 128k the perceptual quality difference is minimal for most listeners. If the original 3G2 was encoded at a low mobile bitrate (often 64k or below), the output quality is already constrained by the source, not the conversion.
WEBA is the conventional extension for audio-only WebM containers, distinguishing them from video-bearing .webm files. Technically both use the same WebM/Matroska-based container, but .weba signals to browsers and media players that the file contains only an Opus or Vorbis audio stream. This matters for web use because some browsers apply different MIME type handling (audio/webm vs. video/webm) based on the extension.
Replace the value after -b:a in the command. For example, change -b:a 128k to -b:a 64k for a smaller file suitable for speech, or -b:a 192k for higher fidelity music. Opus is remarkably efficient at low bitrates — 64k Opus typically sounds better than 128k MP3 — so even the lower options produce acceptable quality for most 3G2 mobile audio content.
Not when the target is WEBA. The WEBA container only supports Opus or Vorbis audio, while 3G2 files contain AAC or MP3. Since there is no codec overlap between the two formats, a transcode is unavoidable. Stream copying (-c:a copy) would only work if you were extracting to a container that supports AAC, such as M4A or MP4.
Generally no. 3G2 files store metadata in MP4-style atoms (like title or creation date), while WEBA uses Matroska-style tags. FFmpeg will attempt to map common tags, but 3G2 mobile files often contain minimal or device-specific metadata that does not transfer cleanly. For critical metadata preservation, consider editing tags in the output file using a tool like MusicBrainz Picard after conversion.
Yes, on the command line you can use a shell loop to process multiple files. On Linux or macOS: for f in *.3g2; do ffmpeg -i "$f" -vn -c:a libopus -b:a 128k -vn "${f%.3g2}.weba"; done. On Windows PowerShell: Get-ChildItem *.3g2 | ForEach-Object { ffmpeg -i $_.FullName -vn -c:a libopus -b:a 128k -vn ($_.BaseName + '.weba') }. This is especially useful for processing large collections of old mobile recordings.
Technical Notes
3G2 (3GPP2) is structurally similar to MP4/MOV, sharing the ISO Base Media File Format lineage, but was specifically profiled for CDMA network transmission with constraints on bitrate and resolution. Audio in 3G2 files is almost universally AAC-LC at low bitrates (32k–128k), reflecting the bandwidth limitations of 2G/3G CDMA networks. The Opus codec used in WEBA output was designed by Xiph.Org and standardized by IETF (RFC 6716), and is the mandatory audio codec in WebRTC — meaning WEBA files are natively compatible with browser audio pipelines. The -vn flag appears twice in the command, which is harmless; FFmpeg processes both instances and simply excludes any video stream from the output. One known limitation: 3G2 files from some older handsets may contain proprietary audio extensions or non-standard AAC profiles that FFmpeg decodes with warnings — the output is usually still usable but may exhibit minor artifacts. WEBA does not support chapter markers or embedded cover art in the same way MP3 ID3 tags do, so any album art stored in the 3G2 container will be lost.