Add your M4A file
Drop one or more .m4a files onto the converter above, or browse for them. They load into browser memory only. Nothing is uploaded, so there is no size-based pricing and no server queue.
M4A to OGG
Re-encoding .m4a audio as .ogg changes how the sound is compressed and which players will accept it. Free, private, and validated: the file never leaves your browser.
Private for supported formats, processed in your browser
Runs on your deviceConvert supported files
Drop M4A files here
Batch files can each use a different output. Nothing uploads for local conversions.
Working inputs include camera RAW, browser-local audio/video, PDF, CBZ/CBR comics, office documents, ebooks, markup, 3D models, structured text, images, and archives.About converting MPEG-4 audio to Ogg audio
Re-encoding .m4a audio as .ogg changes how the sound is compressed and which players will accept it. An .m4a file is an MPEG-4 container that holds only audio, most often AAC and occasionally Apple Lossless. Apple coined the .m4a extension so audio would not be confused with .mp4 video, and it remains the default for iTunes purchases, Apple Music downloads, and Voice Memos.
An .ogg file almost always means Vorbis-compressed audio in the Ogg container, the free-software world's answer to MP3. The .ogg extension originally covered any Xiph media; audio kept the name when video moved to .ogv, and game developers and Wikipedia still lean on it heavily. For this route the practical draw is patent-free from its first release and strong quality at mid-range bitrates, balanced against apple's Music app and iOS offer no native playback, which is worth knowing before you commit a large batch.
Why convert M4A to OGG?
The practical trigger for this conversion is usually a mismatch: with .m4a, the extension hides whether the contents are lossy or lossless, muddying quality expectations. Switching to .ogg buys you patent-free from its first release, which is why it is the better fit for shipping game audio assets without codec royalties. Because the conversion runs locally, trying it costs nothing but a few seconds of compute on your own machine.
M4A vs OGG at a glance
| Aspect | MPEG-4 audio (.m4a) | Ogg audio (.ogg) |
|---|---|---|
| Format type | Lossy: discards detail it judges invisible to shrink files | Lossy: discards detail it judges invisible to shrink files |
| How it stores data | an ISO base media container restricted to audio tracks, structurally a sibling of MP4 | vorbis is an MDCT-based lossy codec tuned through a quality scale (-q) rather than fixed bitrates |
| Strongest at | managing music inside iTunes and Apple Music libraries | shipping game audio assets without codec royalties |
| Weak spot | the extension hides whether the contents are lossy or lossless, muddying quality expectations | apple's Music app and iOS offer no native playback |
| Metadata | iTunes-style metadata atoms: title, album, artwork, composer, BPM, and the iTunSMPB gapless-playback data. A file converted here has an empty atom set, because metadata mapping is disabled on every route: title, album, artwork, composer and BPM are dropped, and no iTunSMPB is written, so gapless playback information does not survive | vorbis comments, the flexible key=value system shared with FLAC and Opus, plus METADATA_BLOCK_PICTURE for embedded cover art. Neither reaches an output written here: metadata mapping is disabled on every conversion, so comments and embedded artwork are dropped in both directions |
Pick OGG as the output
Select .ogg in the output menu next to each file. The menu only offers targets this engine can genuinely produce, so if OGG is selectable, the route is real and validated.
Convert on your device
Press Convert. The transcode runs on an FFmpeg engine compiled to WebAssembly, so the audio never leaves your device.
Verify and download
Each result is checked before the download unlocks: where OGG has a signature or a structure this converter can read back, the file is re-opened and parsed, and where it has neither, the check is that a non-empty file of the declared type came back. A result that fails is reported as an error instead of being offered for download, and outputs keep the original filename with the .ogg extension.
M4A to OGG questions, answered
Will converting M4A to OGG lose quality?
A second lossy step always costs a little, because m4a is lossy-oriented and ogg is lossy-oriented and each encoder discards detail differently (generation loss). At the default quality the difference is rarely visible; avoid repeated round-trips between .m4a and .ogg.
Is it private to convert M4A files here?
Yes. The .m4a file is processed inside your browser tab and never uploaded. The transcode runs on an FFmpeg engine compiled to WebAssembly, so the audio never leaves your device. Close the tab and the file is gone from memory.
Where will the OGG file work?
Chrome, Firefox, and Edge have decoded Ogg Vorbis for many years, and Android plays it natively, while Safari and iOS remained the notable holdouts until only recently. Dedicated players such as VLC and foobar2000 cover the desktop everywhere. Novus Convert writes .ogg with libvorbis in variable-bitrate mode, mapping the quality slider onto the encoder's 0-to-8 quality scale, and the .ogg it produces is always Vorbis: an Ogg container holding Opus or FLAC is not something this target can make, and the separate .opus and .flac targets exist for those. Reading .ogg requires the OggS capture pattern at the head of the file, and input is capped at 500 MB.
Will the OGG file be bigger or smaller than my M4A?
It depends on the content: vorbis is an MDCT-based lossy codec tuned through a quality scale (-q) rather than fixed bitrates. Convert one representative file first and compare before batch-processing a large set.
What happens to the metadata in my M4A file?
This converter strips container metadata deliberately (the FFmpeg command runs with metadata mapping disabled) so exported files do not leak recording details. In the source, iTunes-style metadata atoms: title, album, artwork, composer, BPM, and the iTunSMPB gapless-playback data. A file converted here has an empty atom set, because metadata mapping is disabled on every route: title, album, artwork, composer and BPM are dropped, and no iTunSMPB is written, so gapless playback information does not survive; none of it is transmitted anywhere because the file never leaves your browser.
Can I convert OGG back to M4A?
Yes. The reverse route exists as a separate tool. Bear in mind that round-tripping .m4a → .ogg → .m4a is not a perfect undo when any lossy step is involved; keep your original if fidelity matters.