Step 1: Share your 3GP files using the button above or by drag and drop.
Step 2: Click the 'Transform' button to start the transformation.
Step 3: Grab your converted MP4 files.
3GP to MP4 Transformation FAQ
How do I re-encode 3GP to MP4 without losing video quality?
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Upload your 3GP file and the converter runs a CRF-based re-encode targeting visually-lossless MP4 output (CRF 18 by default, lower values = larger file / higher quality). The codec is chosen to match the MP4 container — H.264 for broad-compat MP4, H.265 for size-efficient MKV, VP9 for WebM, AV1 for newer pipelines. 3GP holds H.263 or MPEG-4 Part 2 video with AMR narrowband speech audio, all tuned for minimal bitrate rather than quality. Almost every MP4 in the wild is H.264 video with AAC audio; the container also legally holds HEVC, AV1 and VP9.
Can 3GP be converted to MP4 without re-encoding the video?
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Yes, and it is the fast path. 3GP and MP4 share the same underlying box structure, so the video and audio streams are copied across byte-for-byte and only the container wrapper is rewritten. Nothing is decoded and nothing is re-compressed, so a feature-length file finishes in under a minute instead of half an hour, with output quality identical to the source. 3GP is the container the 3GPP standardised for early mobile phones, when video had to fit a 176x144 screen and a 2G data plan. MP4 is ISO/IEC 14496-14, standardised in 2001 and derived from the same QuickTime box layout MOV uses.
Can I add selectable subtitles once the file is MP4?
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Yes. 3GP has no usable soft-subtitle track, so subtitles for 3GP content had to be burned into the picture or shipped as a separate sidecar file. MP4 carries subtitles as their own selectable stream, so after conversion you can attach an SRT track the viewer can switch on, switch off or restyle.
Will the MP4 play in a browser when the 3GP would not?
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Yes, and that is usually the whole reason for the conversion. A 3GP embedded in a web page either shows a broken player or forces a download, because browsers ship no decoder for it. MP4 plays inline through the native HTML5 video element with no plugin and no external application. MP4 is the safest possible delivery target — every phone, browser, console, editor and Smart TV built in the last decade plays it without extra software.
Which video codec does the MP4 output use?
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It depends on the MP4 container. MP4 defaults to H.264 for the broadest playback support across phones, browsers, and Smart TVs. MKV defaults to H.265 / HEVC for roughly half the file size at equivalent quality. WebM defaults to VP9. The advanced options expose explicit codec choice if you need to override.
Will my audio track survive 3GP to MP4 conversion?
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Yes. When 3GP and MP4 share an audio codec (e.g. both carry AAC), audio is re-muxed with no re-encode — bit-identical. When the codecs differ, audio is transcoded to AAC / Opus / Vorbis depending on what the MP4 container supports. Multi-track audio (commentary, alternate languages) is preserved.
Can I keep the original framerate when converting 3GP to MP4?
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By default yes — a 24fps 3GP stays 24fps in MP4; a 60fps 3GP stays 60fps. If you need to change rate (e.g. interlaced 29.97 → progressive 30, or 60 → 30 for upload limits), the framerate option handles 3:2 pulldown, deinterlacing, and frame-blending in the same encode pass.
How much will the file size change going from 3GP to MP4?
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Same-codec re-mux (3GP H.264 → MP4 H.264 just changing container): nearly identical size. Codec change can swing dramatically: H.264 → H.265 typically halves the file at the same visual quality; VP9 is roughly comparable; AV1 cuts another 20-30% but is slower to encode.
Will the MP4 file play on iPhone, Android, and Smart TVs?
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MP4 / H.264 plays natively on every modern device. MOV / H.264 plays on Apple devices and most TVs but not always on older Android. MKV needs VLC on iOS. WebM is browser-first. The advanced options include a "device compatibility" preset that picks the safest MP4 codec / container for your target. MP4 only supports one widely-honoured subtitle format (mov_text), and multi-track audio is unreliable outside desktop players.
How long does converting a 1-hour 3GP video to MP4 take?
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Same-codec re-mux is near-instant — 30 to 60 seconds for a 1-hour file. A full codec re-encode runs at roughly 0.3-0.7x source duration on our GPU pipeline, so a 1-hour 3GP → MP4 finishes in 18-40 minutes depending on resolution and target codec.
What is the maximum resolution supported for 3GP to MP4?
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Up to 8K (7680×4320) on Premium plans. Free conversions are capped at 4K (3840×2160) by the per-file size limit. HDR metadata (HDR10, HDR10+, Dolby Vision when present) is carried through where both 3GP and MP4 containers support it.
Is my 3GP video private during conversion to MP4?
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Yes. Uploaded video files are processed in isolated workers, never viewed by a human, never indexed, and deleted within minutes of completion. The retention window is documented at /privacy/ and we publish no training corpus from user uploads.
