3GPP to AIFF Converter

3GPP to AIF: The Codec You Pick Decides Whether You Get AIFF or AIFC

This conversion takes the audio out of a 3GPP mobile clip — a voice memo, a call recording, an old MMS attachment, the sound from a handset video — and writes it as .aif, Apple's Audio Interchange File Format. The picture is discarded; only the sound is kept.

There is one decision on this page that matters more than the rest, and it is not obvious from the labels. The Audio Codec dropdown offers four PCM variants, and your choice does not merely change the samples: it changes which dialect of the format is written. Plain AIFF, the 1988 original, can only hold uncompressed big-endian PCM. Anything else — little-endian samples, mu-law, A-law — has to be written as AIFC, the 1991 extension, with a compression-type field in the header. We measured all four choices, and the results are below.

The Four Codec Choices, Measured

We converted the same five-second 8 kHz mono AMR-NB source with each codec and read the first bytes of every output:

The 54-byte header on the AIFF and the 72-byte header on the three AIFC files account for every byte beyond the raw sample data.

Take the default unless something specific asks otherwise. Logic Pro, GarageBand, Pro Tools and the rest were built around 16-bit big-endian AIFF, and it is the only one of the four that produces a file with AIFF in its header. The mu-law and A-law options halve the size, but they do it by companding roughly fourteen bits of range into eight — a lossy step applied on top of audio the phone already compressed lossily — and they produce a file some older software will refuse because it is technically AIFC.

How to Convert 3GPP to AIF

1. Upload Your 3GPP File: Drag the .3gpp onto the page or click "Add Files". Several clips can be queued and they all run with the same settings, so a folder of voice memos converts in one pass.
2. Choose an Audio Codec: The dropdown opens on PCM 16-bit Big Endian, which produces a true AIFF. The other three — PCM 16-bit Little Endian, PCM mu-law and PCM A-law — all produce AIFC files instead, as the table above shows. There is no File Compression group on this page, because none of these encodings has a quality parameter to set.
3. Set Audio Channel and Audio Sample Rate: Audio Channel offers ORIGINAL, MONO and STEREO; Mono is the right answer for speech and exactly halves the file. Audio Sample Rate lists ORIGINAL first, then 8000, 12000, 16000, 24000, 44100 and 48000 Hz — leaving it on ORIGINAL is almost always correct, for the reason in the sizing section.
4. Convert and Download: Click Convert and save the .aif. Files are uploaded over an encrypted connection, processed on our servers, and deleted automatically after a few hours — no sign-up, no watermark.

What Is Actually Inside Your 3GPP

3GPP is a container defined by the 3rd Generation Partnership Project in specification TS 26.244 and built on the ISO base media file format — the same structural skeleton as MP4. The audio riding inside it comes from a small and predictable set, and which one you have determines everything about the AIFF you get back:

A clip from a feature phone, or any call or voice recording, is almost certainly AMR-NB. A clip from a later handset that also shot H.264 video is probably AAC-LC.

Predicting the File Size

PCM is stored raw, so size is arithmetic — sample rate, times bytes per sample, times channel count, times duration — and nothing about the content changes it. That means you can work out the result before uploading:

This is why raising the sample rate is almost always the wrong move. If the source is AMR-NB at 8,000 Hz, resampling to 44,100 multiplies the file by more than five while adding no audio information whatsoever — AMR-NB filters everything above roughly 3,400 Hz away at the encoder, and no amount of resampling brings it back. Force a specific rate only when a session or a piece of software insists on one.

Frequently Asked Questions

Is .aif the same as .aiff?

Yes — the same format under a shortened extension, a hangover from the eight-character filename limits of early Windows. Nothing about the bytes differs. If your destination expects the longer spelling, 3GPP to AIFF writes exactly the same file under .aiff, and every instruction on this page applies unchanged.

What is AIFC, and will my software open one?

AIFC is the 1991 extension to AIFF that added support for compressed and non-native sample encodings. Structurally it is the same chunked container with a different form type in the header and an extra field naming the compression. Modern audio software reads it without trouble; some older or more narrowly written tools check for the literal AIFF form type and refuse anything else. That is the practical reason to leave Audio Codec on PCM 16-bit Big Endian — we measured it as the only one of the four choices that produces a file identifying itself as AIFF.

Will converting to AIF make my phone recording sound better?

No. AIFF is an uncompressed container, not a restoration tool. If the 3GPP holds AMR-NB, it was captured at 8 kHz and filtered to roughly 200-3,400 Hz, and the AIFF stores exactly those band-limited samples in PCM form — the same telephone character in a much larger file. If it holds AAC, the AIFF carries the decoded AAC samples with no audible change. The value of this conversion is workflow: native PCM your editor can cut and process without decoding first.

Why is my AIF so much larger than the original 3GPP?

Because 3GPP stores audio compressed and AIFF stores it raw. AMR-NB often runs near 12 kbit/s and AAC around 64-128 kbit/s, while 16-bit PCM runs at 16,000 bytes per second for 8 kHz mono and 176,400 bytes per second for 44.1 kHz stereo. The video track is thrown away, but the audio payload expands by one to two orders of magnitude. Keeping the sample rate on ORIGINAL and choosing Mono for speech keeps the output as small as the format allows.

Should I choose mu-law to halve the file size?

Only if the destination expects G.711. Mu-law does halve the output — our measurements came out at 40,072 bytes against 80,054 for the same five seconds — but it does so by companding the dynamic range into eight bits per sample, a lossy step applied on top of a source the phone had already compressed lossily. It also forces an AIFC file. For a smaller file with better sound, 3GPP to MP3 is a far better trade.

What happens if my 3GPP has no audio track?

The conversion fails and no file is written. We confirmed this behaviour directly: with no audio stream to read, the encoder is handed nothing and the job errors out rather than producing a silent .aif. Nothing in the pipeline synthesises silence to fill the gap. If the clip is video-only, or if it is a partial download that never finished, check it in VLC or QuickTime first.

Is there a bit-depth setting?

Not as a separate control — the Audio Codec dropdown is the bit-depth setting, because in AIFF the sample encoding and the bit depth are the same choice. The two 16-bit entries give you 16 bits per sample; mu-law and A-law give you 8 bits per companded sample. There is no 24-bit or 32-bit option here, and adding one would gain nothing: a lossy mobile source has far less effective resolution than 16 bits already provides.

Can I convert only part of the recording?

Yes, and on this page it is the most effective size control there is, because PCM size scales exactly linearly with duration — halving the length halves the file, precisely. Switch Trim from Unchanged to the time range and enter a Start time and a Duration in seconds or as HH:MM:SS.sss; the two fields open at 0 and 10 respectively.

How are my uploads handled and how long are they kept?

Your .3gpp is uploaded over an encrypted connection, decoded on our servers, and both the upload and the resulting .aif are deleted automatically after a few hours. Files are never shared or made public, there is no watermark and no account is needed. If you would rather have little-endian PCM in a RIFF container for a Windows-side tool, 3GPP to WAV writes the identical audio in that form instead.