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Supports: MP3
If you need a small file for Discord, a voice note, a podcast, or anything that plays in a modern browser, Opus is the better codec: it sounds the same as MP3 at roughly half the bitrate. Convert to Opus when size and voice clarity matter; stay on MP3 when you need a file that plays everywhere, including old car stereos and legacy hardware. One honest caveat first: MP3 is already lossy, so transcoding to Opus cannot restore detail MP3 discarded — it only re-packages what is left, more efficiently.
| Property | MP3 | Opus |
|---|---|---|
| Standard | ISO/IEC 11172-3 / 13818-3 | IETF RFC 6716 |
| Year finalized | 1993 | 2012 |
| Codec design | MDCT (single, music-oriented) | Hybrid SILK (speech) + CELT (music) |
| Bitrate range | 8–320 kbps | 6–510 kbps |
| Sample rates | up to 48 kHz | 8, 12, 16, 24, 48 kHz |
| Lossy? | Yes | Yes |
| Royalty status | Patents expired (~2017) | Royalty-free from launch |
| Typical "transparent" bitrate | ~256–320 kbps | ~128 kbps |
| Browser playback | Universal | Chrome 33+, Firefox 15+, Edge 14+; Safari partial |
| Best for | Universal playback, legacy devices | Voice, Discord, streaming, smallest files |
.mp3 they can double-click on any device..opus file. No sign-up, no watermark.No, and no transcode between two lossy formats can. MP3 already removed audio data during its original encoding, and Opus has no way to rebuild it. What Opus does well is hold onto the remaining quality at a much smaller size, so a 320 kbps MP3 re-encoded to Opus at 128 kbps will usually sound about the same while taking far less space.
It depends on the bitrate you target, not the format alone. A 320 kbps MP3 re-encoded to Opus at 128 kbps drops to roughly 40% of the original size with little audible difference. In our testing, a 4-minute track exported from a 320 kbps MP3 to Opus at 96 kbps came out around 2.9 MB versus roughly 9.6 MB for the source.
Both. Opus was designed to encode speech and general audio in one codec — the SILK layer handles voice and the CELT layer handles music, and it switches automatically. For music, 96–128 kbps Opus is the usual sweet spot; for a single speaking voice, 24–32 kbps mono is typically enough.
Yes. Discord uses Opus for its own voice channels, and Opus files generally upload and play back without re-encoding, which is why the small file size is handy when you are near an attachment limit. For sharing files, Discord's upload cap is 10 MB on the free tier (higher with Nitro), so an Opus export often fits where a large MP3 would not.
Mostly on older or offline hardware: basic car stereos, legacy MP3 players, and some older smart TVs may not recognize .opus. Modern browsers (Chrome, Firefox, Edge) and Android play it natively, while Safari support is partial. If a device rejects it, convert it back with our Opus to MP3 converter for maximum compatibility.
Opus files store metadata in Vorbis comments, and common tags like title, artist, and album carry over. Very format-specific MP3 ID3 frames — embedded lyrics or certain custom fields — may not have a direct equivalent and can be dropped. If you only want a smaller file in the same format, the audio compressor re-compresses MP3 without changing the container.