Convert MP3 to M4R — Free
Files convert instantly in your browser — 100% private, any file size, no account needed.
Drop your MP3 file here
or click to browse — any size
Conversion runs entirely in your browser — your file never leaves your device.
How to convert MP3 to M4R
Convert your MP3 audio files to M4R format quickly and securely with BoltConverter. Our free online tool processes your files directly in your web browser using WebAssembly, ensuring your files never leave your device for complete privacy.
M4R is the standard ringtone format for Apple devices. Use BoltConverter to easily create custom iPhone ringtones from your favorite MP3s. Get your conversion done fast without any software downloads or account sign-ups.
Upload Your MP3
Click the 'Choose File' button to select the MP3 audio file from your device.
Start Conversion
Press the 'Convert' button to begin the MP3 to M4R conversion process.
Wait for Processing
The conversion happens instantly in your browser, usually taking just a few seconds.
Download M4R
Once complete, click the 'Download' button to save your new M4R file.
Frequently asked questions
Is BoltConverter free to use?
Yes, BoltConverter is a completely free online tool for everyone to use without any hidden costs.
Do my files get uploaded to a server?
No, all conversions happen directly in your browser using WebAssembly technology, so your files never leave your device.
Is there a file size limit for conversions?
Since files are processed locally in your browser, there is no server-side file size limit imposed by BoltConverter.
What is the quality of the output M4R file?
BoltConverter aims to maintain the original audio quality during the conversion from MP3 to M4R.
Can I convert multiple MP3 files at once?
Currently, BoltConverter processes one file at a time to ensure optimal performance and stability.