Free online OGM to FLAC converter

What the OGM format is

OGM, or Ogg Media, is an Ogg-based container used mainly in the 2000s for video files with Vorbis audio, subtitles, and other streams. Older versions of VirtualDubMod, MPlayer/MEncoder, and OggMux were commonly associated with OGM files; you may still encounter the format in older video archives, anime releases, and media collections.

The .ogm extension identifies the container, not a specific audio codec. An OGM file may contain Vorbis, PCM, or another supported audio stream, and it may also contain video. Converting it to FLAC normally means selecting an audio stream and writing it to a standalone FLAC file.

What the FLAC format is

FLAC is a lossless audio codec and file format. It reduces the size of uncompressed PCM audio while preserving every sample, so it is suitable for archiving, playback, tagging, and editing workflows that support FLAC.

FLAC usually produces larger files than Vorbis or other lossy codecs, but it does not introduce another generation of lossy compression. It supports common metadata such as artist, album, title, track number, and artwork, along with various sample rates and bit depths.

How to actually convert OGM to FLAC

FFmpeg is the most reliable desktop method because it can inspect OGM streams, select a particular audio track, and write FLAC without processing the video. Install FFmpeg, place the OGM file in a working folder, then inspect its streams:

ffprobe -hide_banner input.ogm

Look for entries labeled Audio:. To convert the first audio stream, run:

ffmpeg -i input.ogm -map 0:a:0 -c:a flac output.flac

The option -map 0:a:0 selects the first audio stream and prevents video or additional audio tracks from being written. Replace 0:a:0 with 0:a:1 for the second audio stream. Use a distinct output filename for each track, such as output-eng.flac and output-jpn.flac.

To preserve source metadata when FFmpeg can read it, add -map_metadata 0:

ffmpeg -i input.ogm -map 0:a:0 -map_metadata 0 -c:a flac output.flac

FLAC compression levels affect encoding speed and file size, not audio quality. The default is suitable for most conversions; a higher level can be specified with:

ffmpeg -i input.ogm -map 0:a:0 -c:a flac -compression_level 8 output.flac

If you prefer not to install software, the file can be converted for free on the 101convert.com website. Upload the OGM file, choose FLAC as the output format, start the conversion, and download the resulting file. Check the selected audio track when the source contains more than one.

Quality, compatibility, and limitations

Converting Vorbis audio from OGM to FLAC is a lossless conversion of the decoded signal, not a restoration. If the source was encoded as lossy Vorbis, FLAC preserves its existing artifacts and cannot recover the original uncompressed recording.

FFmpeg will fail if the OGM contains no audio stream or uses an audio codec it cannot decode. A file that contains only video cannot produce a meaningful FLAC output. Inspect the ffprobe result before converting.

After conversion, verify the output with:

ffprobe -hide_banner output.flac

Some players and tag editors handle FLAC metadata more consistently than metadata copied from old OGM files. If tags are missing or incorrect, edit them after conversion rather than changing the audio stream.