Convert 3GP to MP4 on iPhone (Free, No App)

A.3gp file turns up in an old WhatsApp backup, on a memory card from a feature phone, or in a folder someone sent you from 2009. You want it as an MP4 so it plays, shares and uploads like any other video. This post covers what the file is, the route I use, and where it can go wrong.

What a 3GP file is

3GP is a media container built for mobile phones on cellular networks. The details below come from MDN’s reference on media container formats, which I read on 7 Nov 2026.

Question	Answer
What is it for?	Carrying audio and video for transmission over cellular networks to mobile devices
Why does it exist?	It was designed for 3G phones, to suit lower bandwidth
What is it based on?	It is derived from the ISO Base Media File Format and MPEG-4, streamlined for lower bandwidth
Is it still used?	MDN says better bandwidth and bigger data caps reduced the need for it, but it is still used on slower networks and lower-performance phones
MIME types	video/3gpp, video/3gpp2 and video/3gp2 (audio/ versions exist too)
Video codecs it can hold	H.264 (AVC), H.263, MPEG-4 Part 2 and VP8
Audio codecs it can hold	AMR-NB, AMR-WB, AMR-WB+, AAC-LC, HE-AAC v1 and v2, and MP3
Which browsers does MDN list for the container?	Firefox for Android only

Source: MDN, media container formats, read 7 Nov 2026.

The takeaway is that.3gp tells you the wrapper, not what is inside. The same file extension can hold old H.263 video with AMR audio or newer H.264 video with AAC audio. That matters because the codec decides whether a given app can play it.

What Apple lists for iPhone video

Apple’s iPhone 17 technical specifications list the video formats the phone records and plays. I read the page on 7 Nov 2026.

iPhone 17 spec	What Apple lists
Video formats recorded	HEVC and H.264
Video playback, supported formats include	HEVC, H.264 and AV1

Source: Apple, iPhone 17 technical specifications. The line says “include”, so it is not a full list, and it does not name 3GP, H.263 or AMR. Other iPhone models and iOS versions can differ.

So whether a particular.3gp opens on your phone is something to test, not assume. If it opens and plays, you may not need to convert it at all. If it does not, or the recipient cannot play it, convert it.

The route: Grabio hands the file to VERT

Grabio is a free Apple Shortcut that sits in the share sheet. Its video menu treats a.3gp file as a video, and its Convert format (open VERT) option opens a converter with the job set up. VERT is an open source file converter. Its published source lists 3gp and 3g2 among the video formats it handles, alongside mp4.

1. Open the.3gp file in Files. If it is in a chat or an email, save it to Files first.
2. Tap Share, then tap Grabio in the share sheet.
3. In the video menu, choose Convert format (open VERT).
4. Grabio opens VERT in Safari. Pick your.3gp file in the upload area, choose MP4 as the output, and start the conversion.
5. Download the MP4. Back in Grabio’s video menu there is also a Save to Photos option, or you can share the MP4 to Photos yourself.

The manual file pick in step 4 is a rule of iOS, not a Grabio limit. An app cannot place a file into a website’s upload field for you.

Where the file goes

VERT’s README says it converts on your device using WebAssembly, with one footnote for video: local video conversion in the browser is supported, but some conversions may need server-side processing, and server video conversion is available on VERT’s official instance.

VERT’s source also has a separate video converter, vertd, for that server route.

I cannot tell from here which path your particular file takes, so treat a video conversion as one that may leave your phone. If the clip is private, check VERT’s own privacy information first. Sources: VERT on GitHub, read 7 Nov 2026.

If the result will not play

• Play the MP4 in Photos before you delete the original.3gp.
• Very old phone video is small and low resolution. Converting does not add detail, so a tiny clip stays tiny.
• If the clip has no sound, the audio may have been in a codec the converter could not carry over. Keep the original and try the conversion once more.

Related routes

The general map of what an iPhone converts natively and what needs help is in converting any file format on iPhone. The same route handles other awkward containers: AVI to MP4 and WEBM to MP4.

If the video needs to be smaller after converting, see reducing video file size on iPhone, or shrinking a video for WhatsApp. For the broader download cases, downloading an MP4 on iPhone sorts out which situation you are in.

Grabio is free, there is no account and there is no App Store install. Get the Shortcut if you hit awkward file formats often.

3GP to MP4 on iPhone: FAQ

What is a 3GP file?

A media container designed for mobile phones on 3G cellular networks, derived from the ISO Base Media File Format and MPEG-4. It can hold H.264, H.263, MPEG-4 Part 2 or VP8 video and several audio codecs, per MDN.

Can an iPhone play a 3GP file?

It depends on the codecs inside. Apple’s iPhone 17 specs list HEVC, H.264 and AV1 for playback and do not name 3GP, so test the file. If it will not play, convert it to MP4.

Can I convert 3GP to MP4 on iPhone without an app?

Without an App Store app, yes. A free Shortcut can open a web converter with the job set up, and you download the MP4 from it. You pick the file yourself in the converter, because iOS does not let any app fill a website’s upload field.

Does renaming.3gp to.mp4 work?

Not as a conversion. The extension is only a label. The video and audio inside stay in their original codecs, so an app that cannot decode them still cannot play the file.

Does the file leave my phone when I convert it?

It can. VERT says it converts on your device with WebAssembly, but notes that some video conversion may need server-side processing. Check VERT’s privacy information if the clip is private.