3GP to MP4 Converter

Convert 3GP files to MP4 in seconds. Everything runs inside your browser, so your files stay private and there is no size limit or queue.

No uploadNo limitsNo sign-upFree
Processed locally in your browser — your files are never uploaded.

3GP (3GPP Multimedia) and MP4 (MPEG-4 Part 14) are built for different jobs. 3GP is typically used for old feature phones, while MP4 is best for sharing, social media, streaming. Converting lets you open, share or upload your files wherever MP4 is expected.

How to use the 3GP to MP4 converter

  1. Add your 3GP filesClick “Choose Files” or drag and drop them into the box. You can add many files at once — or paste a file with Ctrl+V.
  2. Choose MP4 and adjust settingsMP4 is selected automatically. Optionally open Settings to change resolution, quality or frame rate.
  3. Convert and downloadPress “Convert”. Your MP4 files appear instantly — download them one by one or all together as a ZIP.

3GP vs MP4

3GP 3GPP Multimedia

3GP is a lightweight video format made for early mobile phones and slow networks. Files are tiny and low-resolution — useful for very old phones or tight upload limits.

Compression
Lossy (H.263/H.264)
Features
Video + AAC/AMR audio
Origin
2003, 3GPP
Best for
Old feature phones

MP4 MPEG-4 Part 14

MP4 is the most compatible video format in the world. It plays on iPhones, Android, Windows, Mac, smart TVs and every browser, and is accepted by YouTube, Instagram, TikTok and WhatsApp.

Compression
Lossy (H.264/H.265)
Features
Video, audio, subtitles
Origin
2001, MPEG
Best for
Sharing, social media, streaming

Why use ConvertMathly?

100% private

Files are processed on your device and never uploaded. Close the tab and they are gone.

No limits, no sign-up

No account, no daily cap, no queue and no watermark — convert as much as you want.

Powered by FFmpeg

The same engine used by professional video tools, running in your browser via WebAssembly.

Works everywhere

Windows, Mac, Linux, Chromebook, iPhone and Android — any modern browser, nothing to install.

Frequently asked questions

How do I convert 3GP to MP4?

Add your 3GP files above, make sure MP4 is selected and press Convert. The MP4 files are ready to download a few seconds later — no installation or account required.

Why does the first conversion take a little longer?

The video engine (FFmpeg compiled to WebAssembly, about 30 MB) is downloaded once and then cached by your browser. After that, conversions start immediately — even offline.

Is there a file size limit?

There is no artificial limit. Because the conversion runs in your browser, the practical limit is your device memory — files up to around 1–2 GB work on most computers. Long videos take longer on phones.

Are my 3GP files uploaded to a server?

No. ConvertMathly converts files entirely inside your web browser using JavaScript and WebAssembly. Your files never leave your computer or phone, which makes it safe for private photos and documents.

Can I convert multiple 3GP files at once?

Yes — add as many files as you like. They are converted one after another and you can download everything in a single ZIP.

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