Step 1: Provide your MP4 files using the button above or by toss and let go.
Step 2: Click the 'Convert' button to start the conversion.
Step 3: Fetch your converted 3GP files.
MP4 to 3GP Conversion FAQ
How do I convert MP4 to 3GP without re-encoding the video stream?
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There is no stream-copy switch on this page. A few pairs copy a compatible video stream into the 3GP container without re-encoding it, MKV to MP4 among them, which is quick and loses no quality. Most pairs re-encode the video. Almost every MP4 in the wild is H.264 video with AAC audio; the container also legally holds HEVC, AV1 and VP9. 3GP holds H.263 or MPEG-4 Part 2 video with AMR narrowband speech audio, all tuned for minimal bitrate rather than quality.
Can MP4 be converted to 3GP without re-encoding the video?
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No, not on this page. MP4 and 3GP share the same underlying structure, but the converter re-encodes the video for this pair rather than copying the stream, so it takes longer than a container change and the picture is compressed again. Choose High Quality under Quality to keep the most detail. MP4 is ISO/IEC 14496-14, standardised in 2001 and derived from the same QuickTime box layout MOV uses. 3GP is the container the 3GPP standardised for early mobile phones, when video had to fit a 176x144 screen and a 2G data plan.
What happens to the subtitle tracks in my MP4 file?
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They are dropped. 3GP has no soft-subtitle stream to hold them, and the converter neither burns them into the picture nor exports them as a separate file. If you need them, extract the subtitles to an .srt file with a desktop tool such as ffmpeg or MKVToolNix before converting, and load that file alongside the 3GP in your player. 3GP is capped at low resolutions and mono speech-grade audio; upscaling it will not restore detail that was never captured.
Can I still embed the file on a web page after converting MP4 to 3GP?
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Not directly. MP4 plays inline in every browser; 3GP does not, so a page embedding it falls back to a download link or an empty player frame. If the file is destined for a website, keep the MP4 for the web and treat the 3GP as the archive or editing copy.
Will multi-track audio survive MP4 to 3GP conversion?
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Usually not. Most conversions keep one audio track, the one with the most channels (normally the main mix), re-encoded for the 3GP container, so commentary and alternate-language tracks are dropped. AVI, WMV, MPEG, FLV, VOB and M4V to MKV keep every track, and so does MP4 to MOV. To keep a different track, remux the MP4 with that track first (VLC or ffmpeg can do this), then convert it.
Are subtitle tracks preserved when converting MP4 to 3GP?
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On some pairs. MP4 to MOV keeps every text subtitle track. AVI, WMV, MPEG, FLV, VOB and M4V to MKV keep every subtitle track: text subtitles are copied or converted to SRT, and picture-based subtitles such as DVD or Blu-ray ones are copied as they are. MP4, MOV and WebM to MKV keep only the first subtitle track (as ASS), and MP4 to WebM keeps the first one as WebVTT. Other pairs, including MKV to MP4 or MOV and WebM to MP4, drop subtitle tracks, and the converter does not burn them into the picture. Subtitles that are already burned in stay, because they are part of the video frames.
What about MKV attachments (fonts, cover art) when going MP4 to 3GP?
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MKV is the only mainstream container that stores arbitrary attached files (TTF fonts for ASS subs, JPG cover art, fan-translated PDF inserts). Going from MP4 to 3GP drops these attachments when 3GP is not MKV — the elementary streams convert, but the attached payload stays in the source. Keep MP4 as a backup if you depend on attached fonts.
Which codec does the 3GP output use by default?
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It depends on the 3GP container. MP4, MOV and MKV output use H.264, which plays on practically every phone, browser and TV. WebM output uses VP9. AVI, WMV and MPEG output use the older codecs those formats were designed for. 3GP files are tiny and decode on the weakest hardware imaginable, which is why feature phones and low-end handsets still record it.
How does HDR (HDR10, Dolby Vision) survive MP4 to 3GP?
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There is no HDR processing or tone mapping. When the video stream is copied (MKV to MP4 or MOV with the default settings), HDR10 passes through as it is. When the video is re-encoded, the HDR10 mastering metadata is dropped and Dolby Vision or HDR10+ data is not kept, and with a Quality, Resolution or Frame Rate setting some pairs also reduce the video to 8-bit colour, so an HDR MP4 can look washed out in the 3GP.
Why is my 3GP file smaller / larger than the MP4 after conversion?
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It depends on what happens to the video. MKV to MP4 or MOV with the default settings copies the video stream unchanged, so the size stays close to the source. Most other pairs re-encode it: a high-bitrate MP4 usually comes out smaller, while an already heavily compressed one can grow. Smaller File under Quality gives the smallest output, and H.265 in the Codec setting (MP4, MOV and MKV) is usually smaller than H.264 at similar quality but plays on fewer devices.
