1Upload every file you want combined — at least two of them.
2Drag the uploaded items into the order you want; the order is taken from the list, not from the filenames.
3Start the merge, which joins matching inputs without re-encoding them and reconciles mismatched ones exactly once.
4Download the single combined 3GP file.
Merge 3GP FAQ
How does Merge 3GP join the files together?
+
Concretely, clips with matching codec, resolution and frame rate are concatenated as a stream copy and the join is instant; anything mismatched is normalised to a common format first, which is the slow path but the only correct one. Upload everything you want combined and the result comes back as a single file.
Can I control the order things are joined in?
+
Yes — drag the uploaded items into the order you want before starting. Order is taken from the list, not from the filenames, so "IMG_2.jpg" sorting after "IMG_10.jpg" is not a problem you have to solve first.
Does it matter if the inputs are different formats?
+
It does. 3GP is the cut-down MP4 profile built for early mobile networks, usually very low resolution with AMR audio. Matching inputs take a fast, lossless path; mismatched ones have to be reconciled to a common format, which is slower and costs one encode.
Anything specific to 3GP when merging?
+
Yes — 3GP files are usually very low resolution with AMR speech audio, so there is little detail left to protect and a lot of size to reclaim. That is worth checking when the inputs did not all come from the same source.
How many files can I combine at once?
+
On the free tier a merge accepts two files at a time, which is deliberately higher than the single-file limit on other tools because merging one file is meaningless. A pass removes the cap entirely.
Is the merge lossless?
+
It is whenever the inputs already agree — the encoded data is copied straight through. It stops being lossless only when the inputs disagree and something has to be re-encoded to make them compatible, and even then it is one pass, not one per file.
What can I upload to Merge 3GP?
+
MP4, MOV, MKV, WebM, AVI, WMV, FLV, 3GP, M4V, MPEG and MPG. The container and codec are probed before anything runs, so a mixed batch is handled correctly per file rather than assumed to be uniform.
Is there a file size limit on Merge 3GP?
+
Yes: free accounts process video up to 1 GiB per file, by far the most generous cap on the site; ffmpeg with x264, x265 and libvpx does the work, which is the same toolchain behind most desktop video software. Video is the one family where the cap is high enough that upload time, not the limit, is what you will actually notice.
Will Merge 3GP lower the quality of my 3GP videos?
+
It depends on whether the job needs a re-encode. Operations that only touch the container or the timeline are done as a stream copy and the picture is bit-identical to the source. Anything that has to redraw frames goes through x264/x265 at a quality level you set, where CRF 23 is visually transparent on most footage.
Can I run Merge 3GP on several 3GP videos at once?
+
Yes. Uploads queue in parallel, which matters more here than anywhere else because video jobs are minutes rather than seconds. Free accounts run one file at a time; a pass lifts that.
What happens to audio, subtitle and chapter tracks?
+
They are carried across. Multi-track audio, embedded subtitle tracks and chapter markers survive wherever the target container can represent them — that is the main thing that separates a proper job from a naive re-encode that silently keeps only track one.
Does Merge 3GP cost anything?
+
No. Merge 3GP is free without an account, and the output carries no watermark, no corner logo and no intro card. Uploaded video is deleted from the workers shortly after the job completes.
