Convert OGA to ALAC — Free Online Tool
Convert OGA (Ogg Vorbis/FLAC/Opus audio) to ALAC, Apple's lossless audio codec stored in an M4A container. If your source OGA file uses FLAC audio, this conversion preserves full lossless fidelity; if it uses lossy Vorbis or Opus, the audio is decoded and re-encoded into ALAC without any additional lossy generation loss.
to
FFmpeg Command
Copy this command to run the same conversion locally with FFmpeg on your desktop. Download FFmpeg
Drop your OGA 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
OGA is an Ogg-based audio container that typically holds Vorbis, FLAC, or Opus streams. ALAC (Apple Lossless Audio Codec) is a lossless codec stored in an MPEG-4 (.m4a) container. During this conversion, FFmpeg decodes the source audio stream — whether Vorbis, FLAC, or Opus — into raw PCM audio in memory, then re-encodes it using the ALAC encoder. The result is a lossless M4A file. If the source was FLAC (itself lossless), the decoded PCM is a perfect representation of the original audio, and ALAC will store it with no quality loss. If the source was lossy Vorbis or Opus, the artifacts from that original lossy encoding are already baked into the PCM signal; ALAC will preserve them exactly as-is without adding further degradation. Metadata tags carried in the OGA container are mapped to MPEG-4 atoms in the output file.
What Each Flag Does
| Flag | What it does |
|---|---|
ffmpeg
|
Invokes the FFmpeg binary. This is the same underlying engine that powers the in-browser conversion via FFmpeg.wasm — running this command on your desktop will produce an identical output file. |
-i input.oga
|
Specifies the input OGA file. FFmpeg will detect whether the contained audio stream is Vorbis, FLAC, or Opus and select the appropriate decoder automatically before passing raw PCM to the ALAC encoder. |
-c:a alac
|
Selects the ALAC (Apple Lossless Audio Codec) encoder for the audio stream. This instructs FFmpeg to losslessly compress the decoded PCM audio into ALAC format and package it in an MPEG-4 container, which is determined by the .m4a output extension. |
-c:a alac
|
A duplicate of the preceding codec flag — this is a harmless redundancy in the generated command. FFmpeg applies the last matching codec option, so the effective behavior is identical to specifying `-c:a alac` once. When running locally you may safely omit the first occurrence. |
output.m4a
|
Defines the output filename with the .m4a extension, which signals FFmpeg to use the MPEG-4 container — the correct and required container for ALAC audio. Using a different extension (e.g., .alac or .mp4) would still work technically but .m4a is the standard extension recognized by iTunes, Apple Music, and iOS devices. |
Common Use Cases
- Importing OGA/FLAC music files into iTunes or the Apple Music app on macOS or iOS, which does not natively support the Ogg container format but fully supports ALAC M4A files.
- Syncing lossless audio from a Linux-based music library (where OGA/FLAC is common) to an iPhone or iPod without any quality loss by converting to Apple's native lossless format.
- Archiving OGA files that contain Vorbis recordings into a more universally compatible lossless container for long-term storage, while keeping a single copy rather than a separate lossless master.
- Preparing audio files for use in Final Cut Pro or GarageBand projects, both of which natively handle ALAC M4A but cannot open Ogg-based files.
- Converting a FLAC-in-OGA audiobook or podcast master into ALAC so it can be added to an Apple Books or Podcasts workflow on Apple Silicon Macs.
- Moving losslessly encoded OGA music purchases from an open-source platform into an Apple ecosystem workflow where CarPlay and HomePod require Apple-compatible container formats.
Frequently Asked Questions
No — if your OGA file contains a FLAC audio stream, this conversion is fully lossless end-to-end. FFmpeg decodes the FLAC stream to raw PCM and then re-encodes it with the ALAC encoder, which is also lossless. Every sample value is preserved identically. The output ALAC file will be bit-for-bit equivalent in audio content to the original FLAC source, just repackaged in Apple's M4A container.
Vorbis and Opus are lossy codecs, so the artifacts from that original encoding already exist in the audio signal. Converting to ALAC does not introduce any additional quality loss — ALAC simply captures the decoded PCM exactly as it is. However, the output file will not be 'lossless' in the true sense; it will be a lossless snapshot of an already-lossy source. You won't get any quality back, but you also won't lose any more.
If your OGA contained Vorbis or Opus audio, those codecs achieve very small file sizes through lossy compression. ALAC is a lossless codec, so its files are inherently larger — typically 40–60% of uncompressed WAV size, but still much larger than a lossy Vorbis or Opus file at similar perceptual quality. If your source was FLAC-in-OGA, the size difference between FLAC and ALAC is usually modest (within 10–20%) since both are lossless codecs with comparable compression efficiency.
In most cases yes — FFmpeg maps standard Vorbis comment tags (TITLE, ARTIST, ALBUM, TRACKNUMBER, DATE, etc.) from the OGA container to the equivalent MPEG-4 metadata atoms in the M4A output file. However, some non-standard or custom OGA tags may not have a direct MPEG-4 equivalent and could be dropped. It is worth verifying critical tags in a player like iTunes or foobar2000 after conversion if your library relies on extensive custom metadata.
Yes — ALAC in an M4A container is a first-class format across the entire Apple ecosystem. The Music app on iOS, iPadOS, macOS, and tvOS all natively support ALAC playback. You can sync ALAC files via Finder/iTunes or add them directly to Apple Music. No third-party codec or app is needed.
On macOS or Linux you can run a shell loop: `for f in *.oga; do ffmpeg -i "$f" -c:a alac "${f%.oga}.m4a"; done`. On Windows Command Prompt, use: `for %f in (*.oga) do ffmpeg -i "%f" -c:a alac "%~nf.m4a"`. Each file is processed sequentially, decoded from OGA, and written as a separate ALAC M4A file. This is particularly useful for large libraries that exceed the 1GB browser limit of the online tool.
Technical Notes
ALAC uses predictor-based lossless compression similar in principle to FLAC, but it is encapsulated in the MPEG-4 container (M4A) rather than the Matroska or Ogg containers. The FFmpeg ALAC encoder (`-c:a alac`) supports standard bit depths (16-bit and 24-bit) and sample rates up to 384 kHz, so high-resolution OGA/FLAC sources (e.g., 24-bit/96kHz) are preserved without downsampling. One known limitation: ALAC does not support more than 8 channels, but since OGA itself does not support multiple audio tracks, this is rarely a concern in practice. Chapter markers present in the OGA file are preserved in the MPEG-4 output if they use a compatible format. Embedded cover art in OGA (stored as a Vorbis METADATA_BLOCK_PICTURE) is generally extracted and re-embedded by FFmpeg as an MPEG-4 cover atom, though very large or non-standard artwork blocks may occasionally be dropped. The `-c:a alac` flag appearing twice in the displayed command is a harmless redundancy — FFmpeg honors the last valid codec specification for the audio stream, so the effective instruction is identical to specifying it once.