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OGG to FLAC converter

Convert OGG Vorbis audio to lossless FLAC with adjustable compression.

Free & unlimited
All processing happens in your browser — files never leave your device. The audio engine loads once from a CDN.

OGG Vorbis is a lossy open format, common in games, Wikipedia media and older Linux music libraries. FLAC is its lossless cousin from the same Xiph family. Converting between them does not recover anything the Vorbis encoder discarded — that information is gone for good — but it does produce a file that will never degrade again, which matters when the audio is about to be edited, resampled or moved into an archive. This tool decodes the Vorbis stream and encodes FLAC in your own browser. Compression levels run from 0 to 12, all of them lossless and identical on playback, differing only in encode time and file size. Vorbis comments carry straight over, since FLAC uses the same tagging scheme.

Key facts about OGG to FLAC converter

Key facts about OGG to FLAC converter
Both are Xiph formatsOGG Vorbis and FLAC come from the same foundation and share the Vorbis comment tagging scheme, so tags map across exactly
This does not restore qualityVorbis is lossy. The FLAC will be a perfect copy of an imperfect source
What it does protectNo further loss in any subsequent edit, resample or format move, which lossy-to-lossy always costs
Compression levels0 to 12, default 5. Every level is lossless — higher just means a slower encode for a slightly smaller file
Typical size growthA 5 MB OGG becomes roughly 20 to 30 MB of FLAC, since FLAC must store the full decoded waveform
Level 12 versus level 5Usually a few percent smaller for a noticeably longer encode; level 5 is the standard choice for a reason
MetadataVorbis comments are copied into FLAC tags when preservation is on, which it is by default
Sample rateMatched to the source by default, or forced if a target system needs a specific rate
BatchConvert a folder at once and download the set as a ZIP built in the browser
Size cap200 MB per input file

What happens to your file

The conversion runs on ffmpeg compiled to WebAssembly in a Web Worker inside this tab. Your OGG files are written into that worker's in-memory filesystem, encoded to FLAC, and read back as blobs; the batch ZIP is assembled in the browser. Nothing is uploaded and nothing is retained anywhere. The one network request is the first-time download of the ffmpeg core — roughly 32 MB of fixed public code from the jsDelivr CDN, cached by your browser afterwards and shared with every audio tool here. It carries no part of your audio.

About this tool

  1. 1

    Add your OGG files

    Drop one file or a folder of them, each up to 200 MB. Game audio, Wikipedia downloads and older Linux rips all land here.

  2. 2

    Pick a compression level

    Level 5 is the default and the practical sweet spot. Level 0 is fastest and largest; level 12 is slowest for a few percent saved.

  3. 3

    Check the sample rate

    Leave it on auto unless a target system requires a specific rate. FLAC handles whatever the OGG was recorded at.

  4. 4

    Keep the tags

    Preservation is on by default and matters here, because both formats use Vorbis comments — the mapping is exact rather than approximate.

  5. 5

    Convert

    Files run one after another with per-file progress. The engine loads once and serves the whole batch.

  6. 6

    Download

    Individually or as a ZIP. Keep in mind the FLACs are four to six times larger than the OGGs they came from.

Specs & compatibility
InputOGG Vorbis (.ogg, audio/ogg), up to 200 MB per file
OutputFLAC, native encoder
Compression levels0 to 12, default 5 — all lossless
Sample rateAuto (match source) or forced
MetadataVorbis comments carried to FLAC tags
Batch outputIndividual downloads or a single client-side ZIP
EngineSingle-threaded ffmpeg.wasm 0.12.10
BrowsersChrome, Edge, Firefox and Safari 15+
  • Be clear about why you are doing this. FLAC will not make a lossy OGG sound better; it will stop it getting any worse.
  • Compression level changes file size and encode time only. Levels 0 and 12 decode to identical audio, so there is no quality decision to make here.
  • Level 5 is what most FLAC encoders default to. Going to 8 costs noticeably more time for a small saving; 12 is rarely worth it.
  • The size increase is real: expect four to six times the OGG's size, because FLAC has to store the full decoded waveform rather than a psychoacoustic approximation.
  • If you want a smaller lossless file for archiving, FLAC is already the right answer — but convert from the original source rather than an OGG if you still have it.
  • Tag preservation is more reliable here than in most conversions, since both formats use the same comment scheme and no field mapping is needed.
  • If the goal is compatibility rather than losslessness, converting OGG to MP3 or AAC with the general audio converter makes more sense than FLAC.
  • FLAC compression levels 0 to 12
  • Vorbis comment tags mapped directly to FLAC tags
  • Sample rate matched to source or forced
  • Batch conversion with per-file progress
  • ZIP download for whole folders
  • In-page playback of the result
  • Moving game or Wikipedia audio into a lossless archive format
  • Preparing OGG files for editing without risking another lossy generation
  • Standardising a mixed music library on FLAC
  • Getting OGG audio into software or hardware that reads FLAC but not Vorbis
  • Converting an old Linux music collection into a format modern players handle better
  • Producing a FLAC master copy before a series of edits and resamples
No. OGG Vorbis is a lossy format, which means the encoder permanently discarded audio information judged inaudible. FLAC is lossless, so the file it produces is a perfect, bit-exact copy of the decoded Vorbis — a perfect copy of an imperfect source. What the conversion buys you is protection going forward: any editing, resampling or further conversion from the FLAC costs nothing more, where doing the same from the OGG would add another lossy generation each time.
Encoding time and file size, and nothing else. FLAC is lossless at every level from 0 to 12, so a level 0 file and a level 12 file decode to the exact same samples. Higher levels search harder for efficient predictors, which takes longer and typically saves a few percent. Level 5 is the default in almost every FLAC encoder because it sits where the curve flattens. Level 12 is a long wait for a marginal gain, and level 0 is useful mainly when speed matters more than size.
Typically four to six times the size of the OGG. A 5 MB OGG usually lands somewhere between 20 and 30 MB as FLAC, though it varies with the material — dense, loud music compresses less well than sparse acoustic recordings. The reason for the jump is fundamental: Vorbis throws information away to reach its size, while FLAC must store every sample of the decoded waveform and can only compress it in ways that are perfectly reversible.
Yes, and unusually cleanly. OGG Vorbis and FLAC both come from the Xiph foundation and both use the Vorbis comment tagging format, so the fields map one to one rather than being translated between schemes the way FLAC-to-MP3 has to map into ID3. Artist, album, title, track number and any custom fields carry across intact as long as metadata preservation is left on, which it is by default.
Yes. Drop as many OGG files as you want and they convert in sequence with per-file progress, all using the same compression level and sample rate settings. Download them individually or take the whole set as a ZIP, which is built inside your browser from the converted blobs. Since everything is held in memory rather than on a server, a very large batch of FLACs is bounded by your device's available RAM — worth pacing on a phone.
No. The decode and FLAC encode are performed by ffmpeg compiled to WebAssembly, running in a Web Worker on your own device. Your OGG files go into that worker's in-memory filesystem and the FLACs come back as blobs in your tab; the ZIP is assembled in the browser too. The only network request is the one-time fetch of the ffmpeg core, roughly 32 MB of fixed public code from the jsDelivr CDN, cached afterwards and reused by every audio tool here.

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