Free online RMVB to 3GP converter

Older phones, messaging systems, and media players may accept 3GP but not RMVB, so an RMVB video must usually be decoded and re-encoded before use. The conversion can also reduce file size for low-bandwidth sharing or playback on legacy mobile hardware.

What the RMVB format is

RMVB means RealMedia Variable Bitrate. RealNetworks developed it to assign different bitrates to different parts of a video, using more data for complex scenes and less for simple ones. RMVB files use the .rmvb extension and commonly contain RealVideo and RealAudio streams.

RMVB was common in older internet video collections, downloads, and files produced with RealNetworks software such as RealPlayer or RealProducer. Modern players and editors may not decode it correctly, especially when it contains older RealVideo codecs.

What the 3GP format is

3GP is a multimedia container specified by the 3rd Generation Partnership Project for mobile networks and early mobile phones. Depending on the 3GP version and device, it can contain H.263 or MPEG-4 Part 2 video with AMR-NB or AAC audio.

3GP remains useful when a phone, embedded player, messaging system, or legacy editing application specifically requires .3gp. Its low-resolution profiles and modest bitrates create small files, but they normally provide less quality than the source RMVB. Changing .rmvb to .3gp as a filename does not convert the container or codecs.

How to convert the file

Using 101convert.com

1. Open the RMVB-to-3GP converter on 101convert.com. It can be used free without installing software.
2. Upload the .rmvb file and select 3GP as the output format.
3. Choose a mobile or low-resolution preset if one is available. For many older phones, start with 176×144 pixels, 15 frames per second, mono audio, and a total bitrate below 300 kbps.
4. Start the conversion, download the resulting .3gp file, and test it on the target device or application.

Do not upload confidential video unless the service's handling and retention policies are acceptable. Very large files may also be slower to upload and process.

Using FFmpeg on a computer

FFmpeg provides repeatable control over codecs, dimensions, bitrate, and frame rate. Run this command in the folder containing the source file:

ffmpeg -i "input.rmvb" -vf "scale=176:144:force_original_aspect_ratio=decrease,pad=176:144:(ow-iw)/2:(oh-ih)/2" -c:v h263 -b:v 192k -r 15 -c:a aac -b:a 32k -ar 8000 -ac 1 -f 3gp "output.3gp"

Replace input.rmvb and output.3gp with the actual filenames. The scale and pad filters preserve the source aspect ratio while producing a 176×144 frame. AAC audio works with many newer players; older phones may require AMR-NB instead.

If the installed FFmpeg build includes the AMR-NB encoder, use:

ffmpeg -i "input.rmvb" -vf "scale=176:144:force_original_aspect_ratio=decrease,pad=176:144:(ow-iw)/2:(oh-ih)/2" -c:v h263 -b:v 160k -r 15 -c:a libopencore_amrnb -b:a 12.2k -ar 8000 -ac 1 -f 3gp "output.3gp"

An error saying that libopencore_amrnb is unavailable means the installed FFmpeg build lacks that encoder. Use the AAC command or install a build with AMR-NB encoding support.

Quality and compatibility limits

Conversion cannot restore detail already lost in the RMVB source. Scaling to 176×144 and lowering the bitrate makes the file smaller but visibly softer. Use 320x240 and roughly 300–500 kbps video only when the destination device supports those values.

For older phones, H.263 video, AMR-NB audio, 8 kHz mono audio, 15 fps, and conservative bitrates are generally safer than newer codec combinations. Newer players may accept MPEG-4 video and AAC audio in a 3GP container, but playback can still fail when the resolution, frame rate, bitrate, audio sampling rate, or codec profile exceeds the device's limits.

If FFmpeg cannot decode the RMVB stream, the file may use an unsupported RealVideo variant or may be damaged. Test the source in a current media player and use a current FFmpeg build before troubleshooting the output settings.