AMR to OPUS Converter
Processing entirely on your device — large files may take a moment.
Opus delivers the smallest files with the best quality for streaming and messaging. If your files are still in AMR format, this page is the shortcut: AMR is the tiny voice-recording format of old Nokia-era phones and answering machines.
This converter runs entirely in your browser using WebAssembly — your files never leave your device, nothing is uploaded, and there are no watermarks, sign-ups or queues. Drop in several files at once to convert them as a batch.
How AMR compares to OPUS
| AMR | OPUS | |
|---|---|---|
| Compression | Lossy speech codec | Lossy (6–510 kbps) |
| Quality | Speech only | State of the art |
| Compatibility | Phone recorders | Software strong, hardware lagging |
| Best for | Voice memos and call recordings | Calls, live streams, chat |
How to convert AMR to OPUS
- 1
Select your files
Drag & drop your AMR files onto the area above, or click to browse. You can add multiple files at once for batch conversion.
- 2
Convert instantly
Click "Convert to OPUS". The conversion runs entirely inside your browser using WebAssembly — no upload, no queue, no waiting.
- 3
Download results
Download each converted OPUS file individually, or grab everything at once as a ZIP archive.
About the AMR format
AMR (Adaptive Multi-Rate) is the speech codec of 2G/3G telephony, and the default recording format of countless feature phones and early smartphones. It is optimized exclusively for human voice: narrowband (300–3400 Hz) and wideband (AMR-WB, 50–7000 Hz) modes that make calls sound like calls.
For voice memos it is remarkably compact — a few kilobits per second. For anything musical it is hopeless: cymbals, bass and anything above its band simply do not exist. Convert AMR voice notes to MP3/Opus for archiving and playback anywhere else.
+ Strengths
- ✓Extremely compact for speech
- ✓Native phone-recorder format
! Limitations
- −Voice-only: music quality is unusable
- −Narrow bandwidth sounds dated
About the OPUS format
Opus (IETF RFC 6716, 2012) is the codec that ended the argument: it merges Skype's CELT and Xiph's SILK into one royalty-free format that is simultaneously the best low-latency speech codec and a superb music codec. WebRTC calls, Discord, WhatsApp, WhatsApp calls, YouTube's low-bitrate streams and Zoom all run on it.
At 6 kbps it keeps speech intelligible; at 128 kbps it is transparent for music; latency can dip below 5 ms for live conversation. Its weakness is hardware: dedicated chips and some car/hi-fi devices still lack it, and standalone .opus files are less recognized than MP3 on random devices.
+ Strengths
- ✓Best quality-per-bit across speech and music
- ✓Ultra-low latency — built for live calls
- ✓Royalty-free IETF standard
! Limitations
- −Hardware support still incomplete
- −Not a mastering or archival format
Why convert AMR to OPUS?
Converting makes sense where the strengths of OPUS meet what AMR cannot give you. Best quality-per-bit across speech and music Meanwhile Voice-only: music quality is unusable One pass through the converter above puts your file on the right side of that trade-off.
Frequently asked questions
Is this AMR to OPUS converter really free?
Yes — completely free, with no sign-up, no watermark and no daily conversion limits. The site is supported by advertising.
Are my files uploaded to a server?
No. The conversion runs entirely inside your browser using WebAssembly, so your files never leave your device — that is what makes it instant and private.
Does it work on Windows, Mac, iPhone and Android?
Yes. Anything with a modern browser works: Windows, macOS, Linux, Android and iOS. No software installation is required.
Is there a file size limit for AMR to OPUS?
The only limit is your device's memory, since nothing is uploaded. Files up to a few hundred megabytes work fine on a modern desktop browser; very large files simply take a little longer.
Can I convert a whole folder of AMR files?
You can select many files at once and they are processed in a single batch. Output files land in one ZIP download when there is more than one result.
Will converting AMR to OPUS reduce audio quality?
If OPUS is lossless, the output contains everything the AMR file contains — no further loss is added. If OPUS is lossy, one recompression pass is unavoidable; the quality slider controls how much. Loss that already happened in the source file can never be undone by converting.