Convert FLAC to OGA — Free Online Tool
Convert FLAC lossless audio to OGA format using the Vorbis codec, producing a smaller, streamable Ogg-container file ideal for web and open-source media pipelines. This conversion transcodes the lossless FLAC stream to lossy Vorbis audio at variable-quality level 4 — a solid balance between file size and fidelity.
to
FFmpeg Command
Copy this command to run the same conversion locally with FFmpeg on your desktop. Download FFmpeg
Drop your FLAC file here
or click to browse
Free — no uploads, no signups. Your files never leave your browser.
Settings
Note: Browser-based encoding uses approximate quality targets. For precise CRF compression, copy the FFmpeg command above and run it on your desktop.
Estimated output:
Conversion Complete!
DownloadHow It Works
FLAC stores audio in a lossless compressed form, meaning every sample is preserved exactly. Converting to OGA with the libvorbis codec is a lossy transcode: FFmpeg decodes the FLAC stream to raw PCM audio in memory, then re-encodes it using the Vorbis encoder at the specified quality level (default -q:a 4, roughly equivalent to 128–160 kbps variable bitrate). The resulting stream is wrapped in an Ogg container with the .oga extension, which is the audio-only variant of the Ogg format. Because Vorbis is a lossy codec, some audio detail is discarded during this process — once converted, the lossless original cannot be recovered from the OGA file.
What Each Flag Does
| Flag | What it does |
|---|---|
ffmpeg
|
Invokes the FFmpeg command-line tool. In the browser version of this tool, FFmpeg runs locally via WebAssembly (FFmpeg.wasm), so no audio data leaves your device. |
-i input.flac
|
Specifies the input file — a FLAC lossless audio file. FFmpeg reads and decodes the FLAC stream to raw PCM audio in preparation for re-encoding. |
-c:a libvorbis
|
Sets the audio codec to libvorbis, the open-source Vorbis encoder. This transcodes the decoded FLAC PCM audio into lossy Vorbis format, which is the default and most widely compatible audio codec for the OGA container. |
-q:a 4
|
Sets the Vorbis variable bitrate quality level to 4 on a 0–10 scale, targeting approximately 128–160 kbps VBR. This is a good general-purpose setting that balances file size reduction against audio fidelity for music and voice content converted from a lossless FLAC source. |
output.oga
|
Defines the output file with the .oga extension, signaling an audio-only Ogg container. FFmpeg wraps the encoded Vorbis stream in the Ogg container format and writes the result to this file. |
Common Use Cases
- Reducing the file size of a FLAC music library for storage on a device or server where lossless quality is not strictly required but open-format compatibility is important
- Preparing audio for a web application or browser-based audio player that supports Ogg Vorbis natively (Firefox, Chrome) without relying on proprietary formats like MP3 or AAC
- Converting FLAC archives to OGA for distribution on open-source or Creative Commons music platforms that prefer or require Ogg-based formats
- Transcoding FLAC podcast recordings or voice content to a smaller Vorbis OGA file for faster streaming and lower bandwidth consumption
- Supplying Vorbis audio assets inside an OGA container for use in HTML5 games or interactive web experiences that use the Ogg audio stack
- Converting FLAC tracks to OGA as a format fallback alongside MP3 or AAC to cover browsers and devices that prefer royalty-free open codecs
Frequently Asked Questions
Yes — this conversion is lossy. FLAC is a lossless format, so the source audio is bit-perfect, but Vorbis is a perceptual lossy codec that discards audio data the encoder deems less perceptible. At the default quality level 4 (roughly 128–160 kbps VBR), the result is transparent for most listeners on typical content, but the lossless original cannot be reconstructed from the OGA file. If you need to preserve lossless quality in an Ogg container, you would use FLAC inside OGA instead of Vorbis — though that is a different conversion path.
The .oga extension is the official IANA-registered designation for audio-only Ogg container files, distinguishing them from .ogg files that might carry video or multiplexed streams. Functionally the container format is identical — any player that supports Ogg Vorbis can open an .oga file. Using .oga is more semantically correct and is the recommended practice for audio-only Ogg content.
Partially. Both FLAC and Ogg Vorbis use a comment-based metadata system (Vorbis Comments in the case of Ogg), so standard tags like ARTIST, ALBUM, TITLE, TRACKNUMBER, and DATE are typically carried over by FFmpeg during transcoding. However, FLAC-specific features such as cue sheets and ReplayGain tags embedded in the FLAC stream may not transfer cleanly into the Vorbis OGA container without additional FFmpeg flags, so you should verify critical metadata after conversion.
Adjust the -q:a value in the command. For Vorbis, -q:a accepts values from 0 to 10, where higher numbers produce better quality at larger file sizes. For example, replace -q:a 4 with -q:a 6 for approximately 192 kbps VBR output, or use -q:a 2 for a smaller file at around 96 kbps. A value of -q:a 8 or higher is generally considered near-transparent for most audio content.
Yes. OGA supports FLAC streams natively in addition to Vorbis and Opus. To do this with FFmpeg, change the command to use -c:a flac and drop the -q:a flag: ffmpeg -i input.flac -c:a flac output.oga. This remuxes the FLAC stream into an Ogg container without any quality loss, though the resulting file will be larger than a Vorbis-encoded OGA and the compatibility advantage of the Ogg container is mainly for software that requires it.
The single-file command shown here processes one file at a time, but on a desktop you can wrap it in a shell loop to batch process. On Linux or macOS: for f in *.flac; do ffmpeg -i "$f" -c:a libvorbis -q:a 4 "${f%.flac}.oga"; done. On Windows PowerShell: Get-ChildItem *.flac | ForEach-Object { ffmpeg -i $_.FullName -c:a libvorbis -q:a 4 ($_.BaseName + '.oga') }. For files over 1GB, running FFmpeg locally like this is recommended since the browser tool supports files up to 1GB.
Technical Notes
This conversion involves a full decode-and-reencode pipeline: FLAC's integer-coded lossless samples are decoded to PCM and then fed into the libvorbis encoder, which applies a transform-based perceptual compression model (MDCT with a psychoacoustic masking model). The default -q:a 4 setting targets roughly 128–160 kbps VBR, which is appropriate for music and most voice content. Vorbis does not support sample rates above 192 kHz or more than 255 audio channels in theory, but in practice is well-suited to standard stereo and multichannel audio up to 24-bit source depth. Note that Vorbis encoding always outputs at 32-bit float precision internally, regardless of whether the FLAC source was 16-bit or 24-bit. OGA supports chapter markers in its container metadata, which FLAC does not natively support in the same way, though FFmpeg does not automatically generate OGA chapters from FLAC cue sheet data — this would require additional tooling. Compatibility for OGA/Vorbis is excellent in Firefox and Chrome on desktop and Android, but iOS Safari requires a fallback format since it does not support Vorbis natively.