3G2 to OPUS Converter

3G2 to Opus — Rescue Audio from a Dead-Network Phone Clip

This tool pulls the audio track out of a .3g2 mobile video and saves it as a standalone .opus file — the video frames are discarded, audio only. A .3g2 is a 3GPP2 container written by phones on CDMA2000 carriers (the Verizon- and Sprint-class networks of the 2000s), and those US CDMA networks have been shut down — Verizon switched off its 3G CDMA network on December 31, 2022 — so most .3g2 files today are recordings from phones that no longer have a network to live on. Opus is the modern, royalty-free codec the web and messaging apps run on. If you want the long answer of whether it sounds better, it depends entirely on what the phone captured: see the comparison and the two-case FAQ below.

3G2 vs Opus — Side by Side

The contrast is the whole point of this conversion: a .3g2 is a memory locked inside a container built for a network that no longer exists, while Opus is an open archive format you can play and share for years. Extracting the audio is the smallest, most future-proof way to get that voice memo, recorded call, or MMS clip out of a dead end.

When Opus Is the Right Target

• You want a small, modern, royalty-free file you can back up and play anywhere current.
• The recording is speech — a voice memo or recorded call. Opus's SILK engine descends from the same speech-coding lineage as AMR, so it stores telephone-grade voice faithfully in a tiny file.
• You'll play it on current browsers, Android 10+, or an iPhone on iOS 18.4 or later, or send it through apps like WhatsApp or Discord that play Opus natively.

When to Pick a Different Format Instead

• Your target is older hardware — a pre-2018 car stereo, a basic media player, or a legacy device that never added Opus. Convert the same 3G2 with the 3G2 to MP3 converter for the widest possible reach.
• You're on a desktop browser other than the Safari that ships with iOS — per caniuse, desktop Safari still has only partial Opus support, so MP3 is the safer choice there too.
• You actually want to keep the picture, not just the sound — use the 3G2 to MP4 converter to rewrap the whole clip as playable MP4 video.

How to Convert 3G2 to Opus

1. Upload Your 3G2 File: Drag and drop your .3g2 file onto the page, or click "+ Add Files" to browse. You can queue several clips at once and they all extract with the same settings.
2. Pick a Quality Preset: Open Advanced Options and choose a Quality Preset (Highest through Lowest), or switch to Custom Bitrate, Constant Bitrate, or Variable Bitrate to set an exact target. For feature-phone speech a modest setting is plenty — a higher number only grows the file, it does not add detail the phone never captured.
3. Set Audio Channel, Sample Rate, or Trim: Leave Audio Channel and Audio Sample Rate on "Original" to copy the source, or downmix to Mono and resample for an even smaller file. Use Trim to keep only the part you need.
4. Convert and Download: Click "Convert" and download the .opus file. No sign-up, no watermark.

Frequently Asked Questions

Will converting my 3G2 audio to Opus make it sound better?

There are two cases, and the honest answer for most old phone clips is no. If the 3G2 stores speech — AMR-NB or a CDMA vocoder like EVRC, QCELP/13K, SMV, or VMR-WB — the phone only ever captured the narrow telephone voice band (roughly 200 Hz–3,400 Hz, sampled at 8 kHz for AMR-NB). Opus cannot restore highs and lows the phone never recorded; no bitrate setting invents detail that was never there. If the 3G2 instead holds AAC, you're going lossy-to-lossy, which can't add fidelity either. What Opus does give you in both cases is efficiency and playability — a small, open file you can actually use.

My 3G2 is from an old Verizon or Sprint phone — is the audio still usable?

Yes, as long as the file itself is intact. The CDMA network being shut down (Verizon ended its 3G CDMA service on December 31, 2022) has no bearing on a file already saved to storage — .3g2 clips on an old phone, SD card, or backup play and convert fine. Extracting them to Opus is exactly how you preserve those recordings once the phone that made them can no longer get online. The only thing that stops a conversion is a corrupted or partially transferred file, where the audio track is genuinely unrecoverable.

What bitrate should I choose for the Opus output?

Less than you might expect. Opus was tuned for exactly this low-bitrate speech range, and a CDMA-phone recording carries little detail to begin with. For voice, a Medium preset — or a Variable Bitrate band like 24k–40k — is clean and tiny. If the source is AAC rather than speech, match or slightly exceed its bitrate so the second lossy pass costs as little as possible. Pushing a speech clip up toward 192 kbps just produces a bigger file with no gain in fidelity.

What if my 3G2 already contains AAC instead of a speech codec?

Some later CDMA phones and apps stored AAC inside the 3G2 container (3G2 supports AAC, though not the HE-AAC v2 variant). Re-encoding AAC to Opus is a lossy-to-lossy pass, so pick a Quality Preset or bitrate at or near the source rate rather than far above it. Opus is efficient enough that the generation loss stays negligible at a sensible bitrate. If you'd rather not re-encode at all and just want broad device support, keeping it as AAC with the 3G2 to AAC converter is also reasonable.

Will the .opus file play on my phone, computer, and older devices?

On current targets, yes: Chrome, Firefox, and Edge all play Opus, Android recognizes the bare .opus extension from Android 10 onward, and iPhones play it through Safari from iOS 18.4. The gaps are desktop Safari (still only partial Opus support per caniuse) and a long tail of older hardware — some pre-2018 car stereos and basic media players never added the codec. If your target is one of those, convert the same 3G2 to MP3 with the 3G2 to MP3 converter instead. Note that the .3gp (GSM) cousin of this format works the same way through the 3GP to Opus converter.

Does converting to Opus keep the video, and is my original changed?

No to the video — this is an audio extraction, so the picture is discarded and you get an audio-only .opus file. Your original .3g2 on disk is never modified. If you want to keep the picture alongside the sound in a modern container, use the 3G2 to MP4 converter, which rewraps the clip as playable MP4 video rather than stripping it to audio.

How are my files handled, and how long do you keep them?

Files are uploaded over an encrypted connection, processed on our servers, and deleted automatically a few hours after conversion — no sign-up, no watermark, never shared or made public. In our testing, a 60-second AMR-NB voice clip from a 3G2 file extracted to a roughly 250–350 KB Opus file at a Medium preset — speech stays small because there is little high-frequency detail to encode.