Convert 3GP to 3GPP — Free Online Tool
Convert 3GP files to 3GPP format entirely in your browser, re-encoding video with H.264 (libx264) and audio with AAC while applying the +faststart flag to enable progressive streaming playback on mobile devices. Both formats share the same 3GPP family roots, but this conversion optimizes the output for mobile streaming compatibility and smoother playback initiation.
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FFmpeg Command
Copy this command to run the same conversion locally with FFmpeg on your desktop. Download FFmpeg
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Note: Browser-based encoding uses approximate quality targets. For precise CRF compression, copy the FFmpeg command above and run it on your desktop.
Estimated output:
Conversion Complete!
DownloadHow It Works
3GP and 3GPP are closely related container formats from the Third Generation Partnership Project, both capable of holding H.264 video and AAC audio. During this conversion, the video stream is re-encoded using libx264 with a CRF of 23 (a perceptually balanced quality level), and audio is encoded as AAC at 64k bitrate. The key transformation is the addition of the -movflags +faststart flag, which relocates the MP4/3GPP moov atom to the beginning of the file. This allows a media player or mobile browser to begin streaming and playing the file before the entire download is complete — something the source 3GP file may not support. The result is a 3GPP file better suited for mobile streaming delivery.
What Each Flag Does
| Flag | What it does |
|---|---|
ffmpeg
|
Invokes the FFmpeg binary — the open-source multimedia processing engine that handles all demuxing, decoding, encoding, and remuxing operations for this 3GP to 3GPP conversion. |
-i input.3gp
|
Specifies the input file, a 3GP container typically containing H.264 or MPEG-4 video and AAC or AMR audio as recorded by a 3G-era mobile device. |
-c:v libx264
|
Re-encodes the video stream using the libx264 H.264 encoder, producing a video track that is broadly compatible with 3GPP players and mobile streaming environments. |
-c:a aac
|
Re-encodes the audio stream using FFmpeg's native AAC encoder, which is the standard audio codec for 3GPP containers and is natively supported on virtually all mobile devices. |
-crf 23
|
Sets the Constant Rate Factor for the libx264 encode to 23, a perceptually balanced quality level appropriate for mobile video content. Lower values produce better quality at larger file sizes; higher values compress more aggressively. |
-b:a 64k
|
Sets the AAC audio bitrate to 64 kilobits per second, a standard low-bandwidth target for mobile video that provides intelligible audio quality while keeping file sizes minimal — consistent with 3GPP's low-bitrate design goals. |
-movflags +faststart
|
Moves the 3GPP moov atom to the beginning of the output file after encoding completes, enabling mobile browsers and streaming players to begin playback before the full file has downloaded — the primary functional improvement over a standard 3GP output. |
output.3gp
|
Specifies the output filename with a .3gp extension, which FFmpeg uses to write the resulting 3GPP container holding the re-encoded H.264 video and AAC audio with faststart optimization applied. |
Common Use Cases
- Preparing 3GP videos recorded on older mobile phones for streaming delivery on modern 3G/4G-compatible mobile platforms that require faststart-enabled files
- Optimizing legacy 3GP content for use in mobile web applications where progressive playback is required before the full file has downloaded
- Standardizing a batch of 3GP recordings from feature phones into a consistent 3GPP format with predictable H.264 and AAC codec profiles
- Converting 3GP files from older Android or Nokia devices into a 3GPP container that is compatible with mobile video management systems expecting moov-atom-first files
- Re-packaging 3GP video clips for use in low-bandwidth environments where streaming must begin immediately without buffering the entire file first
- Archiving mobile video content from early smartphones into a well-structured 3GPP container with explicit codec settings for long-term compatibility
Frequently Asked Questions
3GP is an older, more constrained profile of the 3GPP container specification, originally designed for very limited 3G handsets with minimal storage and bandwidth. 3GPP (as a container format) is the broader standard that allows more flexibility, including better streaming support via the +faststart optimization. Converting from 3GP to 3GPP primarily allows you to apply the moov atom reordering (+faststart) that enables mobile browsers and streaming players to start playback before the full file is downloaded, something many original 3GP files do not support.
Yes, there will be a generation loss because this conversion re-encodes the video using libx264 at CRF 23 rather than copying the stream directly. The source 3GP file was already lossy, and re-encoding introduces additional compression artifacts. The default CRF 23 is a good balance for mobile content, but if your source 3GP is already at low quality, you may want to use a lower CRF value (such as 18 or 20) to preserve as much detail as possible. Audio is also re-encoded to AAC at 64k.
The +faststart flag runs a post-processing step that moves the moov atom — the block of metadata describing the file's structure, tracks, and codec parameters — from the end of the file to the beginning. In 3GPP and MP4-family containers, the moov atom must be read before playback can begin. Without faststart, a player must download the entire file to find this atom at the end. With faststart, a mobile browser or streaming player can read the metadata immediately and begin rendering video while the rest of the file transfers.
The video quality is controlled by the -crf flag, which accepts values from 18 (near-lossless, larger file) to 28 (more compression, smaller file) for this tool. To improve quality, lower the CRF value — for example, replace '-crf 23' with '-crf 18'. To reduce file size at the cost of some quality, increase the value to 26 or 28. For mobile content originally captured in 3GP, a CRF between 20 and 26 is usually appropriate given the source material's inherent resolution and quality constraints.
Yes. On Linux or macOS, you can use a shell loop: 'for f in *.3gp; do ffmpeg -i "$f" -c:v libx264 -c:a aac -crf 23 -b:a 64k -movflags +faststart "${f%.3gp}_out.3gp"; done'. On Windows Command Prompt, use: 'for %f in (*.3gp) do ffmpeg -i "%f" -c:v libx264 -c:a aac -crf 23 -b:a 64k -movflags +faststart "%~nf_out.3gp"'. This processes each 3GP file in the current directory and produces a corresponding 3GPP output.
No. Neither the 3GP source format nor the 3GPP output format in this conversion pipeline supports subtitles, chapters, or multiple audio tracks. The FFmpeg command maps only the primary video and audio streams. If your 3GP file somehow contains additional metadata or text tracks, those will be dropped during conversion. This is a limitation of the 3GPP container family's mobile-focused, minimal-overhead design rather than a limitation of the conversion tool itself.
Technical Notes
3GP and 3GPP share the ISO Base Media File Format lineage (the same family as MP4 and MOV), which is why the +faststart flag — typically associated with MP4 streaming — applies equally here. The libx264 encoder used for this conversion produces a Baseline or Main Profile H.264 stream by default, which is broadly compatible with 3G-era and modern mobile devices. Because 3GP files often originate from resource-constrained phones, source resolutions are frequently QCIF (176×144), QVGA (320×240), or CIF (352×288) — re-encoding these at CRF 23 will maintain their original resolution without upscaling. The 3GP input format in this tool includes a special scaling filter (scale=trunc(iw/2)*2:trunc(ih/2)*2) to ensure pixel dimensions are divisible by 2, which is required by libx264 — this guard is important for odd-resolution 3GP files from older handsets. The 3GPP output does not support transparency or lossless encoding, and both input and output are inherently lossy formats. Metadata such as creation timestamps embedded in the original 3GP moov atom may not survive re-encoding intact.