Free online 3GP to FLV converter

Older video editors, Flash-era publishing systems, and some legacy media players accept FLV but reject 3GP, so recordings from older phones may need conversion before use. You can convert the file on 101convert.com without installing software, or use FFmpeg for repeatable settings and batch processing.

What the 3GP format is

3GP is a multimedia container developed for third-generation mobile networks and phones with limited storage and bandwidth. Files commonly use H.263, MPEG-4 Part 2, or H.264 video with AMR-NB, AMR-WB, AAC, or, in some cases, other 3GPP-compatible audio formats.

Older Nokia, Sony Ericsson, Samsung, and other feature phones created 3GP recordings, as did MMS systems and legacy mobile applications. A .3gp extension identifies the container, not one fixed video or audio codec. Many current media players can open 3GP, but older footage may be less compatible with editing or publishing software.

What the FLV format is

FLV, or Flash Video, is a container designed for streaming video through Adobe Flash-based websites and applications. It can contain Sorenson Spark (FLV1), VP6, or H.264 video and MP3 or AAC audio, depending on the target software and the file’s age.

FLV’s useful characteristics for legacy workflows include relatively low container overhead, support for streaming metadata, and compatibility with older Flash-oriented systems. Flash Player has been discontinued, and current browsers and most modern playback systems do not support FLV directly; use FLV only when the destination specifically requires it. For general modern playback, H.264/AAC in MP4 is usually a better target.

Convert the file on 101convert.com

1. Open 101convert.com and select the 3GP-to-FLV converter.
2. Upload the .3gp file.
3. Choose FLV as the output format and start the conversion.
4. Download the resulting .flv file and test it in the application that requires it.

This option requires no software installation and is available free on 101convert.com. Do not upload private or confidential recordings unless the service’s current privacy terms are acceptable for that material.

Convert with FFmpeg

FFmpeg provides command-line conversion, consistent encoding settings, and batch-processing support. After installing FFmpeg, open a terminal in the folder containing the source file and run:

ffmpeg -i input.3gp -c:v libx264 -preset medium -crf 23 -c:a aac -b:a 128k -f flv output.flv

Replace input.3gp and output.flv with the actual filenames. This command decodes the source and re-encodes it as H.264 video and AAC audio inside an FLV container. A lower CRF value generally increases quality and file size; values from about 18 to 28 cover many ordinary uses.

If the receiving application requires an older FLV codec, use FLV1 video and MP3 audio instead:

ffmpeg -i input.3gp -c:v flv -q:v 4 -c:a libmp3lame -b:a 128k -f flv output.flv

The second command is less efficient and may produce lower quality, but FLV1 and MP3 are more compatible with some legacy players. H.264/AAC in FLV is preferable only when the destination supports those codecs; an FLV extension alone does not guarantee compatibility.

Quality and compatibility limits

Conversion cannot restore detail lost in a low-resolution 3GP recording. Re-encoding can reduce quality, so retain the original file and avoid converting the same footage repeatedly. The source may also contain unusual dimensions, a variable frame rate, or damaged timestamps; inspect the output rather than assuming that every 3GP file uses standard video parameters.

If playback is jerky because the destination expects a constant frame rate, normalize it with an additional video filter:

ffmpeg -i input.3gp -vf fps=30 -c:v libx264 -preset medium -crf 23 -c:a aac -b:a 128k -f flv output.flv

If the destination rejects the result, check its required video codec, audio codec, frame size, frame rate, and audio sample rate. Renaming .3gp to .flv does not convert the container or its streams.