Convert OGG to FLAC Online
Convert OGG Vorbis to FLAC container. Honest: no quality improvement. Free, in your browser.
.ogg · up to 100 MB
What you can do
OGG to FLAC: FLAC container for players that do not support OGG
Hi-Fi compatibility
Naim, Linn, Lumin, and Auralic network players that do not support OGG Vorbis accept FLAC.
100% private
Your music never leaves your device. Local processing without servers.
No quality improvement
Full honesty: the FLAC contains the same compressed audio from the OGG. It is a container change.
Metadata preserved
Vorbis Comments (title, artist, album) are transferred in full to the FLAC file.
How it works
Three steps, no hassle
Upload your OGG file
Drag or select your .ogg Vorbis audio file. No signup or installs required.
Local re-encoding
The Vorbis audio is decoded to PCM and re-compressed with the lossless FLAC codec in your browser. Quality does not improve.
Download your FLAC
FLAC file compatible with Hi-Fi players and software requiring the FLAC container.
FAQ
Got questions?
No, it is impossible. This is the most important point about this conversion. Vorbis is a lossy codec: the Vorbis encoding process permanently discards information from the original audio by applying psychoacoustic models similar to those of MP3, based on simultaneous and temporal masking and the absolute threshold of hearing. Once discarded, that information does not exist in the OGG file. When converting to FLAC, the OGG is decoded to a PCM containing only the audio that survived the lossy compression, and that PCM is re-compressed with FLAC losslessly. The result is a FLAC that perfectly preserves the degraded audio of the original OGG. No conversion process can recover information discarded by a lossy codec, because that information is not stored anywhere in the file.
There are legitimate and practical use cases. The most frequent is compatibility with Hi-Fi network players: some high-fidelity audio players like Naim, Linn DS, Lumin, and Auralic have limited or no OGG Vorbis support but accept FLAC without issues. If you have a music library in OGG and want to migrate to a FLAC-based Hi-Fi playback system, this conversion enables that. Another case is collection normalization in software like Roon or Plex, which work better with a single container format throughout the entire library.
Both formats are developed by the Xiph.org Foundation, a non-profit organization dedicated to developing open-source, patent-free multimedia codecs and formats. Vorbis was designed by Chris Montgomery (Monty) and released in 2000 as a free alternative to MP3. FLAC was developed by Josh Coalson and released in stable version 1.0 on July 20, 2001. Both are royalty-free and fully open, unlike MP3 (whose Fraunhofer patents expired in 2017) and AAC (which still has active patent holders).
Yes. Vorbis Comment is the native metadata system for OGG Vorbis files, and FLAC also uses Vorbis Comment as its tagging system. This means metadata (TITLE, ARTIST, ALBUM, DATE, TRACKNUMBER, GENRE, COMMENT, etc.) is transferred directly to the FLAC file without any conversion or data loss. This is one of the advantages of both formats belonging to the same Xiph.org ecosystem.
Considerably larger. An OGG Vorbis at quality q5 (roughly 160 kbps) occupies about 1.2 MB per minute. When decoded to PCM and re-compressed with FLAC, the typical size is 20–35 MB per minute. This is because FLAC compresses PCM efficiently but cannot exploit the psychoacoustic correlations Vorbis uses to reduce size. Expect the FLAC to be 15 to 25 times larger than the original OGG for the same audio content.
Yes. From the player's perspective, a FLAC is a FLAC regardless of its origin. The resulting file is a technically valid and correct FLAC that will work in any software or device with FLAC support: foobar2000, VLC, Winamp, Hi-Fi network players, Roon, Plex, Apple iTunes/Music (with plugin), Android with Poweramp, etc. The player does not know or indicate that the audio was originally Vorbis; it simply plays the decoded PCM from the FLAC.
Convert OGG to FLAC: container change without quality improvement
OGG Vorbis and FLAC are two audio formats developed by the Xiph.org Foundation, a non-profit organization founded by Chris Montgomery (known as Monty) and dedicated to developing patent-free, open-source multimedia codecs and formats. Vorbis was designed by Chris Montgomery and released in stable version 1.0 in July 2000 as a fully free alternative to MP3 (whose Fraunhofer/Thomson patents did not expire in all territories until 2017). OGG is the data stream container (Ogg Bitstream Framing Format) that wraps the Vorbis audio; technically, the container and codec are separate entities, though in practice 'OGG' is colloquially used to mean 'OGG Vorbis'. FLAC (Free Lossless Audio Codec) was developed by Josh Coalson and released in stable version 1.0 on July 20, 2001 under the BSD license. FLAC uses Linear Predictive Coding (LPC) to model the audio signal and Rice-Golomb coding to compress the residuals, achieving 40–60% size reduction compared to WAV without discarding any bits. The fundamental difference: Vorbis is lossy (permanently discards information to achieve high compression), FLAC is lossless (preserves all bits of the original PCM signal). This difference makes OGG to FLAC conversion a container change with re-encoding, not a quality improvement.
The technical reason why converting OGG to FLAC does not improve quality is mathematically clear. The Vorbis codec works through an MDCT (Modified Discrete Cosine Transform) filter bank that transforms audio from the time domain to the frequency domain in blocks of 64 to 8192 samples, applies psychoacoustic models based on the work of Karl Eberhard Zwicker to identify which frequency coefficients can be aggressively quantized or eliminated without the listener perceiving it, and encodes the quantized coefficients using Huffman coding. The information discarded during this process does not exist in the OGG file: there are no bits representing it, there is no way to statistically infer it, and no upsampling or audio enhancement algorithm can authentically reconstruct it. When converting to FLAC, the OGG is decoded to a 16- or 24-bit PCM containing only the audio that survived lossy compression, and that PCM is re-compressed losslessly with FLAC. The result is a FLAC that is technically lossless relative to the input PCM, but that PCM was already degraded relative to the original audio before entering the FLAC codec. Spectral analysis with Spek or Audacity will show the characteristic Vorbis signature: absence of energy above the encoder's cutoff frequency (typically 20 kHz at high quality, 16 kHz at medium quality), exactly like a FLAC from an MP3 source.
Despite not improving audio quality, OGG to FLAC conversion has legitimate applications in 2025. The most important scenario is compatibility with high-fidelity audio ecosystems: OGG Vorbis, despite its excellent quality-per-bitrate and complete absence of patents, has significantly lower support than FLAC in dedicated Hi-Fi hardware. High-end network players such as the Naim ND5 XS2, Naim NDX2, Linn Klimax DS/3, Lumin U2, Auralic Aries G2.2, Aurender N200, and similar devices accept FLAC as their primary format but may have limited, inconsistent, or absent OGG support, especially when files are served from a NAS via UPnP/DLNA. For a user who has built an audio library in OGG Vorbis (common among Linux users and open-source-oriented audiophiles) and wants to migrate to a Hi-Fi network playback system, converting to FLAC is the most direct path. The second use case is collection normalization in music management software: Roon (the most popular high-fidelity music management and playback software in 2025) has OGG support but works optimally with homogeneous FLAC collections. Convertir.ai performs the conversion entirely in the browser via WebAssembly, without sending files to external servers, guaranteeing complete privacy for your personal music collection.