Convert MP4 to 3GP
For the phones the world forgot but people still carry — video shrunk to a size and format an old handset can actually play.
Drop your video or audio here
or
MP4, MOV, WebM, MKV, AVI, MP3, WAV and more — any size, no upload
🔒 Files never leave your device — everything runs in your browser.
MP4 to 3GP is a conversion that still earns its keep in specific places: feature phones that never left circulation, markets where a basic handset and a slow network are the norm, and the occasional constrained device that only understands the older container. If the video has to play on hardware like that, no amount of modern encoding helps — the file has to meet the device where it is.
On your device, the MP4 decodes and re-encodes to MPEG-4 video with AAC audio inside a 3GP container — downscaled hard, because a feature-phone screen has a few hundred pixels to work with and its processor cannot chew through more. The output lands at a fraction of the original size. Be clear-eyed about the trade: 3GP quality is deliberately modest, since the format exists for devices that cannot do better. Nothing uploads; the conversion runs entirely in your browser.
How it works
- Drop your file
Any common format, any size. Nothing is uploaded — the tool runs in your browser.
- Convert
Compatible files are repackaged instantly with zero quality loss; others are hardware-transcoded at high quality.
- Download
Your converted file is ready on your device — nothing to wait for, nothing to delete from a server.
Frequently asked questions
Why does the 3GP look so much worse than my MP4?
Because it is supposed to. 3GP targets devices with tiny screens and weak processors, so the conversion cuts resolution and bitrate aggressively. On the phone it is made for, the small screen hides most of the damage — but the quality loss is real and intentional, not a bug in the conversion.
Should I use 3GP just to make a video smaller for sharing?
No. If the recipient has a modern phone, a compressed MP4 beats 3GP in every way — better quality at the same size, and it plays everywhere. Reach for 3GP only when the target device genuinely requires it; for everything else, use the MP4 compressor instead.
How much smaller will the converted file be?
Dramatically smaller — often a tenth of the original or less. The savings come from resolution: a clip shrunk to feature-phone dimensions simply has far fewer pixels to store, and the modest bitrate 3GP devices expect keeps the rest lean.
Will the 3GP file still play on a computer or modern phone?
Usually, yes — the MPEG-4 video and AAC audio inside are codecs modern players decode without complaint, and VLC opens 3GP directly. But there is no reason to watch it there: keep the original MP4 for modern screens and send the 3GP only to the device that needs it.
Is my file uploaded to a server?
No. ConvertUno runs entirely in your browser on your own device. Your file never leaves your computer or phone — there is no upload at all.
Is it really free, with no watermark?
Yes. Processing happens on your device, so serving you costs us almost nothing — no watermark, no account, no file-size limit, no daily quota.