3GPP to MTS Converter

3GPP to MTS Converter

A .3gpp file is a 3GPP mobile-video container — the same format as .3gp, just spelled out (both extensions are the identical ISO base-media container, so a .3gpp clip and a .3gp clip are read the same way). MTS is the on-camera name for AVCHD, the HD camcorder format Sony and Panasonic introduced in 2006. This converter rewraps a feature-phone .3gpp clip into an .mts file so a video editor can import it alongside real camcorder footage. It is a narrow, editing-only conversion — if you just want a clip that plays and shares, the 3GPP to MP4 converter is almost certainly what you want instead.

3GPP Format at a Glance

MTS (AVCHD) Format at a Glance

How to Convert 3GPP to MTS

1. Upload Your 3GPP File: Drag and drop your .3gpp (or .3gp) file onto the page, or click "+ Add Files" to browse. You can queue several clips and they all convert with the same settings.
2. Set Video Codec and Audio Codec: Open the codec options. Leave Video Codec on H.264 and Audio Codec on AAC — that is the standard AVCHD payload an MTS file is expected to carry, and the defaults already match it. Switch Audio Codec to AC3 (Dolby Digital) only if your editor specifically asks for Dolby audio.
3. Set Video resolution to "Keep original": A feature-phone clip has no HD detail to recover, so leave resolution alone rather than upscaling — see the note below. Use Trim if you only need part of the clip.
4. Convert and Download: Click "Convert" and download the .mts file. No sign-up, no watermark.

Why Keep the Original Resolution

3GPP clips from the feature-phone era were recorded small — typically QCIF (176x144) or CIF (352x288). An MTS file is built to hold 1280x720 or 1920x1080 camcorder footage, so the Video resolution control will happily stretch the clip up to 1080p. Resist it. Upscaling does not add detail the phone never captured; it just spreads the same handful of pixels across a bigger frame, which reads as soft and blocky. The converter cannot invent texture that was never recorded. Leave resolution on "Keep original" and let your editor (Premiere, Resolve, iMovie) frame the small clip as a picture-in-picture or windowed insert on its HD timeline. Note too that 3GPP video is already lossy (H.263 or MPEG-4 Part 2), so re-encoding to H.264 for MTS is a lossy-to-lossy pass — a second compression step that repackages the footage rather than remastering it.

Frequently Asked Questions

Is .3gpp the same format as .3gp?

Yes. .3gp and .3gpp are two spellings of the same 3GPP container, both built on the ISO base media file format (MPEG-4 Part 12). A converter that handles one handles the other identically, and renaming a .3gpp file to .3gp does not change its contents. If you have a clip with either extension, this 3GPP to MTS converter reads it the same way; the 3GP to MTS converter is the same conversion under the other spelling.

Why would I convert 3GPP to MTS instead of MP4?

In almost every case you wouldn't. MTS (AVCHD) is a camcorder and editing format, not a sharing format — its one genuine use is importing old phone footage into a video-editing project alongside clips from a Sony, Panasonic, Canon, or JVC HD camcorder that already record .mts. For playback, sending, uploading, or archiving, convert to MP4 with the 3GPP to MP4 converter, which plays on virtually every device and app. Pick MTS only when an AVCHD workflow specifically asks for it.

Will converting 3GPP to MTS make my old phone video look HD?

No. The footage stays exactly as detailed as the phone originally recorded it — usually around 176x144 or 352x288. Wrapping it in an MTS container, or setting a 1080p resolution preset, does not create detail that was never captured; upscaling only stretches the existing pixels across a larger frame and looks soft or blocky. To keep the picture as clean as the source allows, leave Video resolution on "Keep original" and let your editor scale it on the timeline if needed.

What video and audio codec does the MTS output use?

By default the converter outputs H.264 (MPEG-4 AVC) video with AAC audio, which is the pairing AVCHD tools expect inside an .mts file. AVCHD natively supports Dolby AC-3 and linear PCM audio, so you can switch Audio Codec to AC3 if your editor specifically wants Dolby. Leaving Video Codec on H.264 is almost always correct — other codecs produce a file most AVCHD software refuses to import.

Why does my converted MTS audio sound like a phone recording?

Because that is what the 3GPP captured. Most feature-phone 3GPP clips store AMR-NB audio, a 3GPP speech codec that samples at just 8 kHz and keeps only the 200-3400 Hz telephone voice band. Re-encoding that to AC-3 or AAC inside the MTS preserves the speech faithfully, but no codec or bitrate can restore the high and low frequencies a speech codec never recorded. For a spoken voice memo that is fine; for music captured on an old phone, the fidelity simply isn't there to recover.

How do I go the other way, from MTS back to a mobile clip?

Use the MTS to 3GP converter, which downscales an AVCHD camcorder stream into the small 3GPP container for an old handset. Be aware it is a heavy downgrade in the opposite direction — HD H.264 video is shrunk toward phone-era dimensions and the audio defaults to speech-grade AMR. As with upscaling, the round trip never restores detail; each conversion is a fresh lossy encode.

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 30-second 352x288 3GPP clip kept at its original resolution produced a roughly 3-6 MB MTS file at default H.264/AAC settings; pushing the resolution preset up to 1080p inflated the file several times over without making the picture any sharper.