Free online VOB to 3GP converter

Older phones, legacy media players, and some messaging or editing programs accept .3gp but not DVD-era .vob files. Converting the video creates a smaller file with codecs and dimensions those devices are more likely to support.

What the VOB format is

VOB (Video Object) is the container used on DVD-Video discs. Files in a DVD's VIDEO_TS folder can contain MPEG-2 video, multiple audio tracks, subtitles, navigation data, and menu content; typical names include VTS_01_1.VOB.

A feature-length title is usually split across sequential VOB files, each limited to about 1 GB. Converting only the first file may produce an incomplete video. Identify the complete main-title sequence before starting. Commercial DVDs may also use CSS encryption; conversion is limited to discs and files you are legally authorized to access, and an ordinary converter may not read encrypted content.

What the 3GP format is

3GP is a multimedia container standardized by the 3GPP organization for mobile networks and older phones. Depending on the device and file version, it can contain H.263 or MPEG-4 Part 2 video, and AMR or AAC audio; later devices may also accept H.264.

3GP supports the low resolutions and bit rates used by legacy mobile hardware, so it can be much smaller than DVD MPEG-2 video. The size reduction comes from lower resolution and more aggressive compression, and modern phones generally handle H.264/AAC in an MP4 container more reliably. Use 3GP when the receiving device or application specifically requires it.

Convert with 101convert.com

1. Open the VOB-to-3GP converter on 101convert.com.
2. Upload the VOB file, or upload the relevant title segment if the source is split into several files.
3. Select 3GP as the output format and start the conversion.
4. Download the converted file and test it on the target device or application.

This option requires no installed software and is free to use. A conversion may fail when the VOB is encrypted, damaged, or only one part of a multi-file DVD title is supplied.

Convert with FFmpeg

FFmpeg is a cross-platform desktop tool that provides direct control over codecs, resolution, frame rate, and bit rate. With an FFmpeg build that includes the MPEG-4 Part 2 and AAC encoders, convert one VOB with:

ffmpeg -i input.VOB -map 0:v:0 -map 0:a:0 -c:v mpeg4 -tag:v mp4v -vf "scale=320:-2" -r 15 -b:v 400k -c:a aac -ar 22050 -ac 1 -b:a 32k -f 3gp output.3gp

Replace input.VOB and output.3gp with the actual filenames. The command selects the first video and audio streams, scales the picture to 320 pixels wide while preserving its aspect ratio, and produces a low-bitrate mono file. Use scale=176:-2 and a lower video bit rate for very old phones.

For a title split into VTS_01_1.VOB, VTS_01_2.VOB, and VTS_01_3.VOB, create files.txt in that order:

file 'VTS_01_1.VOB'
file 'VTS_01_2.VOB'
file 'VTS_01_3.VOB'

Then concatenate and encode the segments:

ffmpeg -f concat -safe 0 -i files.txt -map 0:v:0 -map 0:a:0 -c:v mpeg4 -tag:v mp4v -vf "scale=320:-2" -r 15 -b:v 400k -c:a aac -ar 22050 -ac 1 -b:a 32k -f 3gp output.3gp

The segments must belong to the same DVD title and have compatible stream parameters. For a particularly old handset that does not support MPEG-4 Part 2/AAC, try H.263 video and AMR-NB audio if those encoders are available in the installed build:

ffmpeg -i input.VOB -c:v h263 -s 176x144 -r 15 -b:v 180k -c:a libopencore_amrnb -ar 8000 -ac 1 -b:a 12.2k -f 3gp output.3gp

Quality and compatibility limits

DVD video is commonly 720×480 or 720×576 MPEG-2, while legacy 3GP targets are often 176×144 or 320×240. Upscaling the output cannot restore detail removed by the lower-bitrate encode. Keep the original DVD or VOB files when archival quality matters.

A .3gp extension does not guarantee compatibility: phones may reject unsupported video or audio codecs, excessive resolution, stereo audio, or high bit rates. For strict legacy compatibility, use H.263, 176×144 video, 15 frames per second, AMR-NB at 8 kHz mono, and a modest video bit rate. Check the device's documented limits before choosing settings.

VOB subtitles, alternate audio tracks, and DVD menus are not automatically preserved in a simple video conversion. Select the required stream with FFmpeg's -map options or create a separate subtitle track; menus and navigation are discarded.