3GPP to OPUS Converter

Pulling Opus Audio Out of a 3GPP Clip: What This Covers

This tutorial is for anyone holding a .3gpp file — an old voice memo, an MMS recording, a feature-phone camcorder clip — who wants the sound on its own as a small, modern .opus file. It is an extraction: the video track is discarded and only audio comes out. By the end you will know which quality setting is actually worth changing, why an old handset recording will not sound better than it was recorded, and what to do when a device refuses to play Opus at all.

Two things are worth knowing before you start. A .opus file is Opus audio in an Ogg container — the encapsulation the IETF defines in RFC 7845, which also recommends that exact file extension — and the codec itself is RFC 6716, built from Skype's SILK speech coder and Xiph.Org's CELT. And a .3gpp file is the same container as a .3gp file, so if yours carries the shorter extension, 3GP to Opus is the page you want.

How to Convert 3GPP to Opus

1. Upload Your 3GPP File: Drag the .3gpp file onto the page or click "+ Add Files" to browse. Several clips can be queued and they all extract with the same settings.
2. Choose a Compression Mode: Under Advanced Options, File Compression offers a Quality Preset running from Highest down to Lowest, plus "Specific file size", "Custom Bitrate", "Constant Bitrate" (a list from 8 kbps to 384 kbps, sitting on 128 kbps) and "Variable Bitrate" (ranges such as 24k–40k). The walk-through below explains which of those matches an old phone recording.
3. Set Audio Channel, Audio Sample Rate or Trim: Leave Audio Channel and Audio Sample Rate on "Original" to follow the source, or downmix to Mono and resample — 8, 12, 16, 24, 44.1 and 48 kHz are all offered — for a smaller file. Trim keeps only the stretch you actually need.
4. Convert and Download: Click "Convert" and save the .opus. Files are uploaded over an encrypted connection, processed on our servers, and deleted automatically after a few hours — no sign-up, no watermark, never shared or made public.

Walk-through: Matching the Bitrate to the Source

The instinct is to push quality to the top. On a 3GPP voice clip that spends space without buying anything, because the ceiling is the original recording rather than the Opus encoder.

The audio inside a feature-phone .3gpp is almost always AMR-NB, the 3GPP narrowband speech codec: it samples at 8 kHz and runs between 4.75 and 12.2 kbit/s, which covers the telephone voice band and nothing above it. Opus can encode anywhere from 6 kb/s to 510 kb/s at sampling rates from 8 kHz to 48 kHz, so it has enormous headroom over that source — but headroom is not detail. No bitrate reconstructs frequencies the microphone and codec threw away in 2007.

What Opus does bring is efficiency: its SILK layer descends from the same speech-coding tradition as AMR, so telephone-grade voice re-encodes into a very small file with no audible penalty. Aim to match the source, not to overshoot it:

• AMR-NB speech, the usual case: a Constant Bitrate around 24–32 kbps, or a Variable Bitrate range like 24k–40k, is clean and small. Pushing the same clip to 192 kbps grows the file without changing what you hear.
• AMR-WB speech: wideband AMR reaches 23.85 kbit/s at 16 kHz, so give it a little more — 32 to 48 kbps.
• A clip that holds AAC rather than AMR: later handsets and apps stored AAC. That is already lossy, so this is a lossy-to-lossy pass; set the bitrate at or slightly above the source rate to keep the second generation cheap.
• Music or ambient sound rather than voice: 64 to 96 kbps is where Opus stops being obviously compressed on non-speech material.
• You only need part of the clip: trim first, so you are not encoding minutes of silence.

AMR-NB, AMR-WB and Opus Side by Side

Sizing the Output Before You Convert

Opus file size is essentially bitrate multiplied by duration, so you can predict it: bitrate in kbit/s × seconds ÷ 8 gives kilobytes. The table applies that arithmetic to a one-minute clip.

Common Errors and How to Fix Them

• "The output is silent, or the job failed" — the source may hold no audio track at all. Play the original and confirm you can hear something; a video-only clip has nothing to extract.
• "My phone or player will not open the .opus file" — support is broad but not universal. Chrome, Firefox and Edge play Opus, Android has decoded it since Android 5.0, but desktop Safari support is partial and a lot of older hardware never added it. Convert the same clip with 3GPP to MP3 when the target is a car stereo or a legacy player.
• "It still sounds muffled at the highest quality" — that is the AMR-NB telephone band, not a setting. The recording tops out around the upper limit of narrowband speech; no encoder adds what was never captured.
• "The file is bigger than I expected" — you are probably on a high Constant Bitrate. Drop to 24 or 32 kbps for speech, or switch to a Variable Bitrate range so quiet passages cost less.
• "I wanted to keep the picture too" — this page is audio-only by design. 3GPP to MP4 keeps the video and the sound together in a container modern devices open.

When This Doesn't Work

Some files simply cannot be extracted from. If the .3gpp came off an old handset as a partial transfer, or was truncated mid-download, the audio track may be unreadable and the job will fail — there is nothing in the file to recover, and no setting changes that. Play it in VLC first: if VLC cannot decode it either, the source is damaged rather than the conversion. Likewise, a clip recorded without sound has no audio stream to pull, which is not an error so much as an empty pocket. And if your goal is a file you can hand to someone with no questions about codec support, MP3 remains the safer format even though it is technically the weaker one.

Frequently Asked Questions

Does converting to Opus keep the video?

No. This is an audio extraction: the video track is discarded and you get an audio-only .opus file. Your original 3GPP is untouched on your device. To keep the picture along with the sound, convert the clip to a modern video container with 3GPP to MP4 instead.

Will Opus make my old phone recording sound better?

Honestly, no. If the file holds AMR-NB — the usual case for feature-phone voice — the audio was captured at 8 kHz across the telephone speech band at 4.75 to 12.2 kbit/s, and Opus cannot invent what was never recorded. What you gain is a modern, royalty-free file that is far smaller than an equivalent MP3 and plays in current browsers and apps.

What bitrate should I actually pick for a voice memo?

Around 24 to 32 kbps for narrowband speech, or a Variable Bitrate range such as 24k–40k. Opus is unusually strong at low rates because its SILK layer is a speech coder, so those settings sound essentially identical to the source while keeping a minute of audio in the low hundreds of kilobytes. We list Constant Bitrate values from 8 kbps up to 384 kbps and the mode opens on 128 kbps, which is generous for music and several times more than an AMR voice memo can use — anything above roughly 64 kbps here is spent on detail the recording never had.

What if my 3GPP contains AAC audio instead of AMR?

Later handsets and apps did store AAC inside the 3GPP container. AAC is already lossy, so re-encoding it to Opus is a lossy-to-lossy pass — Opus is efficient enough that this is rarely audible if you set the bitrate at or near the source rate rather than far below it. If you would rather not change codec families at all, 3GPP to AAC keeps it in the AAC family, though that path re-encodes as well.

Where will a .opus file play, and where will it not?

Chrome, Firefox and Edge support Opus, and Android has decoded it since Android 5.0 (with encoding support added in Android 10). The gaps are Safari — desktop Safari support is listed as partial, with iOS Safari reaching full support in 18.4 — and a long tail of older hardware such as pre-2018 car head units and basic media players that never implemented it. When the destination is one of those, MP3 is the pragmatic choice.

Why is the .opus file an Ogg file underneath?

Because that is what the specification says. RFC 7845 defines how Opus streams are encapsulated in Ogg and recommends .opus as the filename extension, registering audio/ogg as the media type. So a .opus file is an Ogg container carrying an Opus stream — which is why some tools report it as Ogg, and why renaming it to .ogg usually still plays.

Can I make the file smaller without dropping the bitrate?

Yes, in two ways. Downmix Audio Channel to Mono if the source is a single speaker — most phone recordings are mono to begin with, so this often costs nothing. And use Trim to cut the clip down before encoding, since duration multiplies directly into file size. Resampling with Audio Sample Rate can help too, but there is little point resampling below what the source already contains.

How are my files handled during conversion?

They are uploaded over an encrypted connection, processed on our servers, and deleted automatically after a few hours. There is no sign-up and no watermark, nothing is shared or made public, and the original clip on your device is never modified — only the .opus you download comes back out.