3GP to MP4 Converter
Convert 3GP and 3G2 videos from old mobile phones to MP4 that plays on any modern phone, computer or TV, with full control over quality, bitrate, frame rate, resolution and audio — including the old H.263 video and AMR voice audio those phones used.
Also: MKV to MP4 converter · AVI to MP4 converter · MOV to MP4 converter · WebM to MP4 converter · FLV to MP4 converter · TS to MP4 converter · WMV to MP4 converter · MPEG to MP4 converter · M4V to MP4 converter · MOD to MP4 converter · VOB to MP4 converter · MTS to MP4 converter · OGV to MP4 converter · RM/RMVB to MP4 converter · MXF to MP4 converter · MP4 compressor · Video to MP3 extractor · MP4 to GIF converter · Video format converter
Click to choose a video, or drag and drop
Choose a 3GP or 3G2 file — MKV, AVI, MOV, WebM, TS, FLV and most other formats are accepted too. Stays on your device.
Your video is converted entirely in your browser and is never uploaded. The converter engine (ffmpeg, ~32 MB) is downloaded once and cached by your browser.
Frequently asked questions
Why convert 3GP to MP4?
3GP was made for early mobile phones with tiny screens and slow networks. Modern computers, TVs and many apps and editors no longer handle it well, and the old H.263 video and AMR audio inside it are poorly supported. MP4 with H.264 and AAC plays everywhere. If a 3GP already contains H.264 and AAC, it is simply repackaged without quality loss.
Why is my 3GP video so small and blurry?
Old phone videos were recorded at resolutions such as 176×144 or 320×240 with heavy compression. Converting cannot add detail that was never recorded, so keep the original resolution, or enlarge it only slightly if you need a bigger picture. Raising the quality (a lower CRF) will not make a blurry source sharper.
What happens to the AMR audio?
AMR is a low-bitrate voice codec that MP4 players do not support, so the audio is converted to AAC. The sound quality stays the same as the source, which is voice-grade. Use a low AAC bitrate such as 64 kbps, since a higher one only makes the file bigger.
Will the video still be rotated correctly?
Phone videos recorded upright often carry a rotation flag instead of rotated pixels. When the tool re-encodes the video it applies that rotation automatically, so the result plays upright in every player.
Is my video uploaded anywhere?
No. The conversion runs entirely in your browser using ffmpeg compiled to WebAssembly. Your video never leaves your device. Only the converter engine itself (about 32 MB) is downloaded, once, and cached by your browser.
What is Fast remux and when should I use it?
A 3GP file is just a container. If the video inside is H.264 (or another format MP4 supports) and the audio is AAC, MP3 or AC-3, those streams can be moved into an MP4 container as they are. That takes seconds and loses no quality at all. The tool checks your file and picks this automatically when it is possible.
What do CRF and bitrate mean?
CRF (constant quality) lets the encoder spend as many bits as each scene needs: lower numbers mean better quality and bigger files, around 18 looks near-lossless, 23 is the default and 28 is noticeably smaller. A target bitrate instead aims for a fixed number of kilobits per second, which gives a predictable file size but variable quality.
Why is re-encoding slow, and is there a size limit?
Re-encoding runs on a single CPU thread inside the browser (H.264 only), so it is usually near real-time speed or slower for HD. The finished MP4 also has to fit in browser memory, which in practice limits output to roughly 1 to 2 GB. For a long movie, use Fast remux, trim it, or copy the generated command and run it with ffmpeg on your own computer.
What happens to subtitles?
MP4 supports text subtitles only. SRT, ASS/SSA and WebVTT tracks are converted to the MP4 text format, and you can also save a track as a separate .srt file. Picture-based subtitles from Blu-ray or DVD (PGS, VobSub) cannot be converted.