OpenAnyFile
What is a .amr file?
Adaptive Multi-Rate Audio is an audio format developed by 3GPP, first released in 1999. It is usually created by Older phone voice recorders, voicemail.
A speech codec running at 4.75–12.2 kbit/s. Chrome and Firefox cannot decode it, so the inspector confirms the codec when playback is not possible.
File details
| Full name | Adaptive Multi-Rate Audio |
|---|---|
| Category | Audio |
| MIME type | audio/amr |
| Signature (magic bytes) | 23 21 41 4D 52 (#!AMR) |
| Developer | 3GPP |
| Introduced | 1999 |
| Opens with | Audio player |
| Uploaded? | No — read locally in your browser |
How to open a .amr file
OpenAnyFile routes .amr files to its audio player, which shows a player with duration and seeking, if your browser has the codec.
- Drop your .amr file on the box above, click it to choose the file, or paste it with Ctrl+V.
- The real format is detected from the file's first bytes — not just its name.
- The file opens in the audio player.
- Use fullscreen for a closer look, check its checksums, or download it back unchanged.
What works — and what does not
Works
Viewing and inspecting: a player with duration and seeking, if your browser has the codec. Size, type, signature and checksums are always shown.
Does not work
Guaranteed playback. It depends on your browser shipping this codec; if it doesn't, you still get the full inspection.
Is it safe to open a .amr file online?
Here, yes — because nothing is uploaded. Most "online viewers" send your file to their server. OpenAnyFile reads it with your browser's File API and decodes it on your own device, so there is no copy anywhere else. You can check: open your browser's network tab while opening a file — no upload appears.
Questions about .amr files
Can I open a .amr file without installing software?
Yes. OpenAnyFile opens .amr files in your browser using its audio player. You get a player with duration and seeking, if your browser has the codec, with nothing installed and no account.
How do I know a file is really a .amr file?
Check its first bytes instead of its name. A genuine AMR file begins with 23 21 41 4D 52 (#!AMR). OpenAnyFile shows the detected type, so a renamed file is easy to spot.
Is my .amr file uploaded anywhere?
No. The file is read locally by your browser and never sent to a server — it even works offline once the page has loaded.
Does it work on phones?
Yes — on Android and iPhone, in any modern browser. You can also install OpenAnyFile as an app.
Related formats
Other formats from the same family:
Format facts checked and page updated on September 25, 2026.