3G2 to M4A Converter

Convert 3G2 to M4A Online

Pull the soundtrack out of an old .3g2 clip and get a plain .m4a file that plays on any modern phone, laptop, or car stereo. 3G2 is the 3GPP2 container CDMA-network handsets recorded to, and its audio is often a cellular speech vocoder that current apps simply do not decode; M4A wraps AAC audio in the MPEG-4 container that iPhones, Android, iTunes, Windows, and browsers all handle natively. The video is discarded — M4A is audio-only — and the conversion buys you reach, not fidelity: a re-encode cannot restore frequencies the phone's vocoder never recorded.

How to Convert 3G2 to M4A

1. Upload Your 3G2 File: Drag and drop, or click "Add Files", to select .3g2 (or .3gp) clips. Batch is supported, so a folder of old phone recordings runs as one job; the video track is read only to locate the audio.
2. Set the Bitrate under File Compression: The panel opens on Quality Preset, the hands-off mode — nothing is pre-selected in that dropdown, and it is the least predictable control here. For a faithful transfer name the rate yourself with Constant Bitrate, which maps one-to-one onto the encoder: the dropdown runs from 8 kbps to 384 kbps and opens on 128 kbps. Variable Bitrate and its five AAC bands (96k-112k down to 20k-32k) are the quality-targeted alternative. The same panel also offers Custom Bitrate (which starts at 128 kbps) and Specific file size when you need to hit an exact figure or a size budget.
3. Set Audio Channel, Audio Sample Rate, or Trim (Optional): Audio Channel offers Mono and Stereo, and Audio Sample Rate offers 8000, 12000, 16000, 24000, 44100, and 48000 Hz; leave both untouched to keep the source's own values. Use Trim if you only want one passage.
4. Convert and Download: Click Convert and save the .m4a. Files upload over an encrypted connection, are converted on our servers, and are deleted automatically a few hours later — no sign-up, no watermark.

What's Actually Inside a 3G2's Audio Track

Every conversion here is a real decode-and-re-encode, so the goal is to lose as little as possible rather than to gain anything. If the source is a narrowband vocoder, a very high bitrate is wasted on audio that never carried more than telephone bandwidth; if the source is already AAC, a bitrate at or above the source keeps the extra generation of loss small.

M4A, MP3, or Something Lossless?

Frequently Asked Questions

Does this keep the video, or only the audio?

Only the audio. M4A is an audio-only container by design — that is precisely why Apple introduced the .m4a name rather than shipping audio inside .mp4 — so the picture is discarded and you receive just the soundtrack. If you want to keep both, 3G2 to MP4 re-encodes video and audio together into one playable file, and 3G2 to M4V does the same under Apple's movie extension.

Will converting an EVRC or QCELP clip to M4A make it sound better?

No. EVRC, EVRC-B, QCELP (13K), and SMV are narrowband CDMA speech vocoders working at an 8 kHz sampling rate — roughly the bandwidth of a phone call — and AAC cannot reconstruct frequencies that were discarded at capture. The output plays everywhere modern and still sounds like the tinny original. The one exception is a source recorded with EVRC-WB or VMR-WB, which are wideband at 16 kHz and audibly fuller to begin with.

What does the M4A actually gain me over the original 3G2?

Playability. .3g2 is a legacy CDMA2000 container that many current players refuse — and even when the container opens, the vocoder inside often does not decode, giving you silence or an error. AAC inside M4A plays natively on iPhone, Android, iTunes, QuickTime, Windows, and modern browsers, so the audio becomes usable on devices people own today. That is the entire value proposition of this conversion.

What bitrate should I pick for old phone audio?

Less than you would use for music. A narrowband vocoder source carries so little bandwidth that a very high AAC bitrate mostly encodes silence above 4 kHz — a Constant Bitrate in the 64-96 kbps range, or one of the lower Variable Bitrate bands, is usually indistinguishable from the top of the ladder for speech. Reserve high bitrates for sources you know were recorded as AAC, where the re-encode really is a second generation of lossy compression. Whichever figure you settle on, state it under Constant Bitrate rather than the Quality Preset dropdown: the presets are the hands-off, least predictable route, and nothing is pre-selected there, so leaving the panel on the "Highest" it shows at load hands the decision to the server's own default.

Should I set Audio Channel to Mono?

Only if you know the recording is mono, which most single-microphone phone clips are. Leaving Audio Channel untouched keeps whatever the source had, which is the safe default. Forcing Stereo on a mono source does not create stereo — it duplicates one channel into two and roughly doubles the data for no benefit; forcing Mono on a genuinely stereo recording irreversibly folds the channels together.

Is M4A better than MP3 for this?

At equal bitrate AAC is generally more efficient than MP3, so M4A is the better technical default and the natural choice inside the Apple ecosystem. MP3 still wins on sheer ubiquity — old car stereos, DAP players, embedded hardware, and some upload forms accept nothing else. If the file has to work on unknown or elderly hardware, use 3G2 to MP3; if it is going to a phone or computer bought this decade, M4A is fine.

My .3g2 files came off an old Verizon or Sprint phone — will they work?

That is the main use case for this page. .3g2 was the container CDMA2000 handsets used, which in the US meant carriers like Verizon and Sprint, and Verizon shut its 3G CDMA network down on December 31, 2022 — so these files are pure archive material now. Our decoders handle the CDMA vocoders that make the clips unplayable elsewhere. Files with the GSM-side .3gp extension work too, either here or on 3GP to M4A.

Why does my converted M4A sound quieter or shorter than expected?

Two common causes. Voice-optimised vocoders apply aggressive noise suppression and can gate near-silent passages, so a quiet recording can decode quieter still — normalise it in an audio editor afterwards if that matters. A short output usually means the Trim panel is active with a duration set; clear it to convert the whole clip. If the output is entirely silent, the source clip most likely had no audio track at all.

What happens to my files after conversion?

Each upload travels over an encrypted connection, is converted on our servers, and is deleted automatically a few hours later, along with the result. Nothing is shared or made public, there is no sign-up, and the M4A carries no watermark. On a long recording, upload time is the practical bottleneck — trimming before you convert is the fastest way to shorten a job.