Y4M to 3GP Converter
Processing entirely on your device — large files may take a moment.
Rescuing old phone videos means converting 3GP to MP4 before the memories become unreadable. If your files are still in Y4M format, this page is the shortcut: Y4M is uncompressed video with a text header — the interchange format of video-filter pipelines (avisynth/vapoursynth) and encoder test suites.
This converter runs entirely in your browser using WebAssembly — your files never leave your device, nothing is uploaded, and there are no watermarks, sign-ups or queues. Drop in several files at once to convert them as a batch.
How Y4M compares to 3GP
| Y4M | 3GP | |
|---|---|---|
| Compatibility | ffmpeg, x264, vapoursynth | Legacy phones |
| Best for | Filter-pipeline interchange | Old mobile footage |
How to convert Y4M to 3GP
- 1
Select your files
Drag & drop your Y4M files onto the area above, or click to browse. You can add multiple files at once for batch conversion.
- 2
Convert instantly
Click "Convert to 3GP". The conversion runs entirely inside your browser using WebAssembly — no upload, no queue, no waiting.
- 3
Download results
Download each converted 3GP file individually, or grab everything at once as a ZIP archive.
About the Y4M format
Y4M (YUV4MPEG2) is uncompressed video with a one-line text header: resolution, framerate and color space, then raw YUV frames. It is the lingua franca of video-filter pipelines — AviSynth, Vapoursynth and encoder test suites pass frames around as Y4M because there is nothing to misparse.
A Y4M of any real length is enormous (30MB per second of 1080p), so conversion to MP4/WEBM with H.264 or VP9 is always the destination — the value is in the zero-ambiguity input, not the format itself.
+ Strengths
- ✓Zero-ambiguity pixel format declaration
- ✓Standard between filter frameworks
- ✓Lossless by construction
! Limitations
- −No compression whatsoever
- −Color space variants (limited/full) trip decoders
- −Not natively playable in browsers
About the 3GP format
3GP is the 3GPP mobile video format from the pre-smartphone era, designed for 2G/3G bandwidth: low resolution (typically 176×144 to 640×480), H.263 or baseline H.264 video, and AMR audio. Every early camera phone recorded in it, and MMS messaging depended on its small footprint.
It is strictly a conversion source today: pull the videos off an old phone, convert to MP4, and enjoy a resolution upgrade from better scaling alone. Quality expectations should stay low — the pixels were never there.
+ Strengths
- ✓Tiny files for its era
- ✓Plays on old feature phones
! Limitations
- −Very low resolution and quality ceiling
- −Obsolete; no modern platform wants it
Why convert Y4M to 3GP?
Converting makes sense where the strengths of 3GP meet what Y4M cannot give you. Tiny files for its era Meanwhile No compression whatsoever One pass through the converter above puts your file on the right side of that trade-off.
Frequently asked questions
Is this Y4M to 3GP converter really free?
Yes — completely free, with no sign-up, no watermark and no daily conversion limits. The site is supported by advertising.
Are my files uploaded to a server?
No. The conversion runs entirely inside your browser using WebAssembly, so your files never leave your device — that is what makes it instant and private.
Does it work on Windows, Mac, iPhone and Android?
Yes. Anything with a modern browser works: Windows, macOS, Linux, Android and iOS. No software installation is required.
Is there a file size limit for Y4M to 3GP?
The only limit is your device's memory, since nothing is uploaded. Files up to a few hundred megabytes work fine on a modern desktop browser; very large files simply take a little longer.
Why is video conversion slower than image conversion?
Every frame has to be decoded and re-encoded. This site runs that work on your own CPU via WebAssembly — nothing is uploaded, but a multi-minute video reasonably takes a few minutes. Images, by comparison, are single-frame jobs.
Will the audio track be kept?
Yes. The audio is carried over and re-encoded to the standard audio codec of 3GP, staying in sync with the video. If your Y4M file has multiple audio tracks, the first one is used.