Add your AMR file
Drop one or more .amr files onto the converter above, or browse for them. They load into browser memory only — nothing is uploaded, so there is no size-based pricing and no server queue.
Re-encoding .amr audio as .m4r changes how the sound is compressed and which players will accept it. Free, private, and validated — the file never leaves your browser.
Batch files can each use a different output. Nothing uploads for local conversions.
Working inputs include camera RAW, browser-local audio/video, PDF, CBZ/CBR comics, office documents, ebooks, markup, 3D models, structured text, images, and archives.Re-encoding .amr audio as .m4r changes how the sound is compressed and which players will accept it. An .amr file stores speech compressed with the Adaptive Multi-Rate codec, engineered to squeeze a voice call into a few kilobits per second. Feature phones saved voice notes and MMS clips as .amr, and the format still surfaces in old phone backups and some Android recorder apps.
An .m4r file is an iPhone ringtone: AAC audio in an MPEG-4 container, identical to an .m4a in everything but the extension. Apple uses .m4r purely as a routing marker so iTunes and iOS file the audio under Tones instead of Music. For this route the practical draw is the only ringtone format iOS accepts and full AAC quality, indistinguishable from the source track — balanced against tones over 40 seconds are rejected outright, which is worth knowing before you commit a large batch.
The practical trigger for this conversion is usually a mismatch: with .amr, telephone-grade fidelity: nothing above roughly 3.4 kHz survives. Switching to .m4r buys you the only ringtone format iOS accepts, which is why it is the better fit for turning a favorite song's hook into a custom iPhone ringtone. Because the conversion runs locally, trying it costs nothing but a few seconds of compute on your own machine.
| Aspect | Adaptive Multi-Rate audio (.amr) | Apple ringtone (.m4r) |
|---|---|---|
| Format type | Lossy — discards detail it judges invisible to shrink files | Lossy — discards detail it judges invisible to shrink files |
| How it stores data | narrowband AMR samples at 8 kHz, mono only, across bitrates from 4.75 to 12.2 kbps | shares the ISO base media layout of .m4a, carrying AAC-LC audio |
| Strongest at | retrieving voicemail exports and call recordings from old handsets | turning a favorite song's hook into a custom iPhone ringtone |
| Weak spot | telephone-grade fidelity: nothing above roughly 3.4 kHz survives | tones over 40 seconds are rejected outright |
| Metadata | none; the storage format is a bare magic number followed by speech frames, with no tagging structure at all | standard iTunes atoms apply, though iOS shows only the title in the ringtone picker |
Drop one or more .amr files onto the converter above, or browse for them. They load into browser memory only — nothing is uploaded, so there is no size-based pricing and no server queue.
Select .m4r in the output menu next to each file. The menu only offers targets this engine can genuinely produce, so if M4R is selectable, the route is real and validated.
Press Convert. The transcode runs on an FFmpeg engine compiled to WebAssembly, so the audio never leaves your device.
Each result is signature-checked before the download unlocks, so a failed encode can never masquerade as a valid M4R file. Outputs keep the original filename with the .m4r extension.
A second lossy step always costs a little, because amr is lossy-oriented and m4r is lossy-oriented and each encoder discards detail differently (generation loss). At the default quality the difference is rarely visible; avoid repeated round-trips between .amr and .m4r.
Yes — the .amr file is processed inside your browser tab and never uploaded. The transcode runs on an FFmpeg engine compiled to WebAssembly, so the audio never leaves your device. Close the tab and the file is gone from memory.
iPhones accept .m4r only through iTunes or Finder sync and GarageBand export, and every Apple device can play it since the audio is ordinary AAC. Other platforms open the file happily after a rename, though Android sources its ringtones from plain MP3 or OGG instead.
It depends on the content: shares the ISO base media layout of .m4a, carrying AAC-LC audio. Convert one representative file first and compare before batch-processing a large set.
This converter strips container metadata deliberately (the FFmpeg command runs with metadata mapping disabled) so exported files do not leak recording details. In the source, none; the storage format is a bare magic number followed by speech frames, with no tagging structure at all; none of it is transmitted anywhere because the file never leaves your browser.