Free online OGM to WEBM converter

What the OGM format is

OGM, or Ogg Media, is an older multimedia container based on Ogg. It was used mainly for downloaded films, anime, and other videos that combined formats such as Xvid or DivX video with Vorbis audio, and it could contain multiple audio tracks and subtitles.

OGM files are commonly encountered in older media collections and may have been created with tools such as OGM tools, VirtualDubMod, or older versions of DVD and video encoding software. The .ogm extension identifies the container, not one specific video codec, so two OGM files can require different conversion settings.

What the WEBM format is

WEBM is a Matroska-based container designed primarily for web video. Standard WebM files use VP8, VP9, or AV1 video with Vorbis or Opus audio, making them suitable for HTML5 playback, browser-based applications, video sharing, and lightweight distribution.

WEBM usually provides better browser compatibility than OGM and avoids the legacy MPEG-4 ASP, DivX, or Xvid codecs often found inside OGM files. Opus audio and VP9 or AV1 video can reduce file size at comparable quality, although encoding takes longer than simply copying streams.

How to convert OGM to WEBM

Using FFmpeg

FFmpeg is the most controllable desktop method. Install a current FFmpeg build, open a terminal in the folder containing the source file, and run:

ffmpeg -i input.ogm -map 0:v:0 -map 0:a:0? -c:v libvpx-vp9 -crf 31 -b:v 0 -c:a libopus -b:a 128k output.webm

This selects the first video and, if present, the first audio stream, then transcodes them to VP9 and Opus. Replace input.ogm and output.webm with the actual filenames. Lower the VP9 -crf value for higher quality and a larger file; values around 28–35 are a practical range.

For faster encoding with a potentially larger file, use VP8 and Vorbis:

ffmpeg -i input.ogm -map 0:v:0 -map 0:a:0? -c:v libvpx -crf 10 -b:v 1M -c:a libvorbis -q:a 5 output.webm

To inspect available streams before converting, run:

ffprobe input.ogm

Use additional -map options when the file contains a desired alternate audio track. For example, -map 0:v:0 -map 0:a:1 selects the first video and second audio stream.

Using an online converter

You can convert the file for free on 101convert.com without installing software. Upload the OGM file, select WEBM as the output format, start the conversion, and download the resulting file. Avoid uploading confidential or copyrighted material when the service’s handling policy does not meet your requirements.

Quality, compatibility, and limitations

Most OGM files need full transcoding because Xvid, DivX, and other OGM video codecs are not valid WebM codecs. Changing only the filename extension does not convert the video and will not make it browser-compatible.

Transcoding is lossy: quality may decrease, and the output can become larger if the bitrate or CRF is poorly chosen. Keep the original OGM as an archive and test the WEBM output before deleting it.

OGM subtitle streams may not transfer correctly because WebM has narrower subtitle support than OGM. Extract subtitles separately, for example as .srt or .vtt, when the target player does not display them. Chapters, menus, unusual metadata, and multiple audio tracks can also be lost unless they are explicitly mapped and supported by the WebM muxer.