Convert MP3 to OGG
Make small OGG Opus files for games and the web, on your own device.
- Nothing is uploaded
- Works offline after first use
- Open source
- No watermark · limit is your device’s memory; phones hold less
Convert MP3 to OGG Opus in your browser for games, websites and Discord bots. It is free, needs no account and adds no watermark, and your files are not uploaded: everything runs in your browser on your device. The size limit is your device’s memory, and phones hold less; give the page a short while after your first run to save itself for offline use, and then it works offline.
Done
Open the network tab. Your files never appear in it.
Add files and run the tool to see every request this tab makes.
Your files are processed on this device and never sent to a server. Reload the page to clear everything from memory.
OGG is an open container that browsers, Discord and many Linux apps prefer. This page writes it with Opus, the modern codec inside it, which sounds as good as MP3 at around two thirds of the bitrate and is what Discord and WhatsApp use for voice.
Each MP3 is decoded and encoded by your browser’s own Opus encoder, so nothing is uploaded and there is no file limit. 128 kbps Opus is transparent for music; 96 kbps is plenty for sound effects and speech.
A common job is a folder of sound effects or music loops for a web page or a browser game. Drop the whole folder and they come back as a zip of .ogg files with the same names. For short effects that your audio library places around the player, choose Mono: sounds that move in 3D space are usually expected to be mono, and the whole bitrate then goes to one channel. Keep Stereo for background music. The files are written at 48 kHz, the rate Opus always uses.
Opus is efficient, so the saving is real. A 320 kbps MP3 at 2.4 MB a minute becomes about 0.96 MB a minute at 128 kbps, and a page that loads a dozen sounds gets noticeably lighter. Converting cannot bring back detail the MP3 already lost, so there is no point going above 128 kbps. If you have the original WAV of a track, convert that instead of the MP3 for the cleanest result.
How it works
- Drop one or more MP3 files, or tap to pick them.
- OGG at 128 kbps is already chosen. Use 96 kbps for effects or speech.
- Convert. Each OGG downloads when it is ready; several come as a zip.
In your browser, not on a server
Your browser decodes the sound with the decoders it uses to play media on any website. The new file is written in your tab: MP3 by LAME compiled to WebAssembly, WAV by a few lines of code, FLAC by a small lossless encoder in this site’s code (fixed predictors and Rice coding, as the FLAC format describes), and M4A or OGG by the browser’s own AAC and Opus encoders (WebCodecs), packed by Mediabunny (MPL-2.0). WAV and FLAC keep the original sample rate.
Compared with upload-based tools: Online audio converters upload every file, queue it, cap free use at a few files or a few hundred megabytes, and keep the upload for hours. Recordings of meetings, unreleased songs and voice memos are private. Here the files never leave your device and a whole folder converts at once.
Verify it yourself. Give the page a short while after your first run to save itself for offline use, then turn off Wi-Fi or switch to airplane mode and run the tool again. Or open your browser's developer tools (F12, or Cmd-Option-I on a Mac), pick the Network tab, and watch it while you convert. The panel above does the same count for you.
Questions
Is it OGG Vorbis or OGG Opus?
Opus. Browsers can encode Opus but not Vorbis. Firefox, Chrome, VLC, Discord and most Linux players play Opus in OGG; some older players and game engines only know Vorbis.
Does Safari support it?
Recent Safari plays OGG Opus. Making the file works in Chrome, Edge and Firefox; if Safari cannot, the page says so when you choose OGG.
Will my game engine import OGG Opus files?
Check with one file before converting a whole folder. Browsers, VLC and many players read Opus in OGG, but some engine versions and importers only read OGG Vorbis and reject Opus, even though both use the .ogg name. If yours refuses the file, keep the MP3 or WAV for that engine, since this page cannot write Vorbis.
Should I use OGG on a website instead of MP3?
It saves bandwidth, but serve an MP3 alongside it for older Safari versions and devices that do not play Opus. An audio element with two source lines, the OGG first and the MP3 second, lets each browser pick the file it can play. For a single background track the saving may not be worth keeping two copies.
Is the file uploaded anywhere?
No. There is no server in this process. The page is a static file and the work is done by code running inside your browser tab. Give the page a short while after your first run to save itself for offline use; then you can turn off Wi-Fi and it still works.
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Guides
- How to convert WAV to MP3WAV files are large; MP3 is the smaller, more compatible format most people actually need. Here is how to convert between them.
- A free CloudConvert alternative for everyday filesCloudConvert measures its free tier in credits tied to conversion time, not files, which makes it hard to predict when you will hit the limit. Here is an alternative with nothing to meter.
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- How to merge audio filesJoining voice notes, podcast segments or songs end to end is simple once you know the right tool. Here is the desktop way and a private browser way.
- How to reduce MP3 sizeAn MP3 gets smaller when you lower its bitrate, make it mono, shorten it, or switch format. Here is what each saves, with measured results.