OGG → MP3
OGG to MP3 converter
Ogg Vorbis audio is decoded and re-encoded as MP3 so it plays on hardware that never supported Vorbis. Both codecs are lossy, so this costs one generation of quality.
…or drag files and folders here. Add as many as you like — everything is processed on this device.
.oga .ogg .opus
In one paragraph
Vorbis is excellent and free of patent baggage, which is why Godot, Unity, Wikimedia and countless game mods use it. It is also unsupported by a large amount of consumer hardware: most car head units, older iPods, DJ controllers and set-top boxes simply will not see an .ogg file.
This page decodes Vorbis with a self-hosted WebAssembly build rather than relying on the browser, which matters because Safari and iOS ship no Vorbis decoder at all. The same page therefore works identically on a Mac, a Windows PC and an iPhone.
Does this change the audio quality?
Vorbis at quality 5 is roughly equivalent to a 160 kbps MP3. Re-encoding at 192 kbps keeps the result close to the source; encoding at 320 kbps mostly stores the Vorbis codec’s artefacts in greater detail rather than improving anything.
- A .ogg file can contain Vorbis, Opus, FLAC or Speex. Sonic Batch reports the codec it actually found before you convert.
- Vorbis comments (tags) are mapped to ID3v2 where an equivalent frame exists; unusual custom fields are dropped and listed as a warning.
- Chained Ogg streams — several logical streams in one file, used by some internet radio dumps — convert as the first stream only.
A worked example
Making a game’s music folder playable in a car
- Select every .ogg in the game’s music directory. Sonic Batch shows which are Vorbis and which are actually Opus.
- Keep 192 kbps stereo, source sample rate.
- Convert all, then Download ZIP — the archive keeps the original filenames with a .mp3 extension.
- Copy the ZIP contents to a USB stick for the car stereo.
Read the source quality first, then match it
Look at the per-file source panel: it shows the average bitrate of the Ogg. Pick the nearest MP3 bitrate at or slightly above that number — 128 kbps Vorbis → 160 kbps MP3, 192 kbps Vorbis → 192–224 kbps MP3. MP3 is slightly less efficient than Vorbis, so matching the number exactly tends to lose a little more than it needs to.
Supported formats, limits and browser notes
Sonic Batch decodes with the browser when it can (faster, no engine download) and falls back to the self-hosted WebAssembly engine when it cannot. Every combination below works in every listed browser; the column only tells you which decoder does the work.
| Input | What it is | Chrome | Firefox | Safari | iOS |
|---|---|---|---|---|---|
| OGG | Royalty-free lossy codec. Standard in game engines, Godot, Unity and Wikimedia. | Native | Native | Engine | Engine |
| Opus | The best-sounding lossy codec below 128 kbps. Used by WhatsApp, Discord and YouTube. | Native | Native | Partial | Partial |
| Output | Encoder | Bitrates / depth | Sample rates | Tags |
|---|---|---|---|---|
| MP3 | libmp3lame | 32–320 kbps | 8–48 kHz | Yes + artwork |
- Max per file
- 400.0 MB
- Max per queue
- 4.00 GB
- Max duration
- 4:00:00
- Max archive
- 1.50 GB
These are enforced ceilings, checked before any decoding starts, not measured maximums — a file over the limit is rejected rather than allowed to exhaust the tab’s memory. Real-world capacity is lower on older phones, which is why the scheduler runs one file at a time on iOS and Safari.
Where your audio goes
Nowhere. Your file is read from disk into this browser tab with the File API, decoded and encoded by code running in that same tab, and handed back to you as a download. It is never transmitted.
That is a structural property of the application, not a policy promise: there are no API routes, no server actions and no third-party processing services in this project, so there is nothing capable of receiving a file. The page’s Content-Security-Policy also restricts connections to this origin, and the automated test suite includes a browser test that fails if any network request during import, preview, conversion or download carries media bytes.
The trade-off, stated plainly:results live in your tab’s memory until you download them. Closing or reloading the page discards them. There is nothing on a server to recover, because nothing was ever put there.
Troubleshooting
Safari says it cannot play the file when I try to preview it.
That is the browser’s own player, not Sonic Batch. Safari has no Vorbis decoder, so the source preview is disabled and the page tells you so — conversion is unaffected because the engine decodes Vorbis itself.
The output MP3 is longer than the OGG.
MP3 frames are a fixed 1,152 samples, so the encoder pads the last frame and LAME writes a short lead-in. A difference of up to ~50 ms is normal and is flagged in the manifest when it exceeds 250 ms.
My file is actually .oga — will it work?
Yes. .oga is the audio-only Ogg extension and is accepted here.
Frequently asked questions
Is OGG better than MP3?
At the same bitrate, Vorbis is generally a little more efficient than MP3, especially below 128 kbps. MP3’s advantage is universal hardware support, which is normally the reason for this conversion.
Will converting to MP3 improve the audio?
No. Nothing can add back what the Vorbis encoder discarded. This conversion buys compatibility, not quality.
Can I convert MP3 back to OGG?
Yes, on the MP3 to OGG page — but be aware that round-tripping between two lossy codecs degrades the audio each time.
Does it handle hundreds of small game files?
Yes. Short files are the fastest case: the engine loads once and is reused for the whole queue, so the WASM start-up cost is paid a single time.