Convert 3GP to MP3 - extract audio
Old smartphone recordings sit in 3GP files with AAC or AMR audio inside (see Codecs vs containers for the wrapper vs. codec framing). Wave discards the video and re-encodes the audio to a portable 192 kbps MP3 that plays on any device.
What actually changes
3GP was the multimedia container early smartphones (Nokia, Motorola, early Android) recorded to. Video-carrying 3GP files hold AAC or AMR audio alongside H.263 or H.264 video. AMR (both narrow-band and wide-band) was designed for voice - cellular-grade audio that's clear for speech but bandwidth-limited for music. Wave decodes both AMR variants locally through its wasm ffmpeg core.
Because the video track is discarded, extract runs several times faster than a full 3GP-to-MP4 conversion. Wave uses LAME (libmp3lame) at VBR around 190 kbps - well above the transparency threshold for voice, which is what most 3GP audio actually is.
AMR came in two variants: AMR-NB (narrow band, 4.75-12.2 kbps, 8 kHz sample rate, designed for GSM voice calls) and AMR-WB (wide band, 6.6-23.85 kbps, 16 kHz sample rate, marketed as "HD Voice" in the mid-2000s). Wave decodes both. The MP3 output is much higher bitrate than either AMR variant needs, but that is fine - MP3 at 192 kbps preserves whatever the source captured; the audio does not become better than the source, just archive-safe.
This extract is what people reach for when they find a decade-old 3GP recording of a family member speaking, a voice memo from an ancient phone, or an early smartphone concert clip they want to preserve as audio. The MP3 output is portable in a way the .3gp never was - iPhone, Android, Windows, any car stereo, any music library all play the resulting file directly.
Three steps.
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Step 1
Drop your 3GP file onto the card.
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Step 2
Pick MP3 as the output format.
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Step 3
Convert and save the MP3.
Answers, specifically.
The audio sounds tinny - can Wave fix it?
No. AMR narrow-band caps audio bandwidth around 4 kHz - designed for cellular voice calls, not music. The MP3 will sound as clear as the AMR did, no better and no worse. Preserving the audio at its native quality is the honest choice.
What if my 3GP is a voice memo (audio-only)?
Wave rejects audio-only sources - it's a video-to-audio extractor, not an audio-to-audio converter. A dedicated audio tool is the right fit for a voice-memo .3gp.
What about 3G2 files?
3G2 (the CDMA variant used on older Verizon and Sprint phones) uses the same container structure with slightly different codec constraints. Wave treats .3g2 identically to .3gp.
Does the MP3 include the recording date?
Basic ID3 tags (title) are written from the filename. 3GP creation-date metadata doesn't map neatly to MP3, so it's dropped.
How fast is it?
Extracts complete in well under a minute for typical 3GP file lengths - most 3GP clips are short by design because the phones that recorded them were memory-constrained.
What is the maximum bitrate the MP3 usefully carries?
The source is the limit. AMR-NB caps around 12.2 kbps audio content; encoding that at 192 kbps MP3 is fine but the actual audio quality never rises above the AMR ceiling. This is why Wave defaults to a moderate MP3 bitrate for consistency rather than pushing higher.
Can I hear a person clearly enough to transcribe them?
Yes if the phone was close to them. AMR was designed for cellular voice calls, so a speaking person captured near the phone comes through clearly. Speech from across a room, or a whispered aside, may not - those situations were beyond what phone-camera audio hardware could resolve at the time.
What about 3G2 file variants?
Same story. 3G2 (CDMA carrier variant) uses the same audio codec set as 3GP (GSM variant). Wave handles both extensions identically.