Turn any song into a real iPhone ringtone. Each MP3 is trimmed to the best 20, 30 or 40 seconds (the loudest part is picked for you), faded in and out, encoded as AAC and saved as a genuine .m4r file with its title, artist and cover art. Convert one song or a whole batch; your music never leaves your device.
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Ringtone length
Every file is trimmed to the length above, because iPhone ringtones can be at most 40 seconds.
Choose the part for
Drag the green box to move it, drag its edges to resize (up to 40 s), or drag across the waveform for a new selection. Arrow keys nudge a focused edge by 0.1 s (Shift: 1 s).
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How to use the MP3 to M4R
Add your MP3 files: drop them on the box or click to choose. M4A, WAV, OGG and FLAC work too.
Choose the length and start: 20, 30 or 40 seconds, starting at the loudest part or at the beginning, plus fades and AAC quality.
Fine-tune a song (optional): press Edit part, drag the green box over the waveform, press Play selection to hear it and rename the ringtone.
Press Convert to M4R. Each file shows its progress and the new file size.
Download the .m4r files one by one or press Download all (ZIP), then add them to your iPhone (see the steps below).
Add the M4R ringtone to your iPhone
Your computer
Steps
Mac (macOS Catalina or later)
Connect the iPhone with a cable, open Finder and select the iPhone in the sidebar. Drag the .m4r file onto the iPhone's General tab. It syncs straight away.
Windows (iTunes or Apple Devices app)
Connect the iPhone, open the device in the app and drag the .m4r file into the device's Tones section (or onto the device in the sidebar).
Older Mac with iTunes
Add the .m4r file to the Tones library, then sync tones to the iPhone.
On the iPhone
Open Settings → Sounds & Haptics → Ringtone (or Text Tone) and pick your new tone. You can also set it per contact.
If the file does not appear, check that it is 40 seconds or shorter and that the extension is .m4r, not .m4r.m4a.
How the conversion works
The MP3 is decoded to raw audio by your browser's Web Audio API and resampled to 44.1 kHz.
The selected part is cut out, faded in and out with straight-line volume ramps and, if you ask for it, normalized so its loudest sample is at −1 dBFS (about 89% of full scale).
The audio is encoded as AAC-LC in 1,024-sample frames, either by the browser's WebCodecs AudioEncoder or by ffmpeg compiled to WebAssembly.
The frames are written into an MPEG-4 file with the M4A brand and an iTunes-style tag block (title, artist, album, cover art), then saved with the .m4r extension.
File size is roughly bitrate × seconds ÷ 8: a 30-second ringtone at 192 kbps is 192,000 × 30 ÷ 8 = 720,000 bytes, about 0.7 MB.
Tips for a great ringtone
Start on a strong moment. A ringtone often plays only a few seconds before you answer, so the chorus or a catchy hook works better than a slow intro.
Use a short fade-out (1 to 2 seconds) so the loop back to the start does not click.
Normalize quiet songs. Classical and acoustic tracks can be hard to hear in a pocket; normalizing raises them without distortion.
Keep it to 30 seconds if you also want to use it as a text or alert tone.
Only convert music you own or have the rights to use.
Frequently asked questions
What is an M4R file?
M4R is the file type Apple uses for iPhone ringtones and alert tones. Inside it is AAC audio in an MPEG-4 container, exactly like an .m4a music file, but with the .m4r extension so iTunes, Finder and the iPhone treat it as a ringtone.
How long can an iPhone ringtone be?
Ringtones can be up to 40 seconds long; longer files are not accepted as ringtones. Alert and text tones are best kept to 30 seconds or less. That is why this tool trims every file to 20, 30 or 40 seconds.
Can I just rename an MP3 to .m4r?
No. Renaming does not change the audio inside: an MP3 renamed to .m4r is still MP3 data and is rejected by Finder, iTunes and the Music app. The audio must be re-encoded as AAC, which this tool does.
How do I put the M4R ringtone on my iPhone?
On a Mac, connect the iPhone, select it in Finder and drag the .m4r file onto the General tab. On Windows, use iTunes or the Apple Devices app and drag the file into the device's Tones section. Then choose it in Settings, Sounds & Haptics, Ringtone.
Are my songs uploaded to a server?
No. The MP3 is decoded, trimmed and faded by your browser. AAC encoding uses the browser's built-in WebCodecs encoder when available, otherwise a WebAssembly build of ffmpeg that is downloaded once and runs on your device.
Which AAC bitrate should I choose?
192 kbps is plenty for a phone speaker and keeps a 30-second ringtone around 0.7 MB. Choose 256 kbps for the same quality as music bought from Apple, or 128 kbps for the smallest files.
Are the song title and album art kept?
Yes, when the option is on. Title, artist, album, album artist, year, genre, track number and the embedded cover image are copied from the MP3's ID3 tags into the M4R file. You can also type a new ringtone name, which becomes the title shown on the iPhone.
Are all the tools on FreeToolCabin tested for quality and accuracy?
Yes! Every tool on our site undergoes automated Q/A testing in real browser environments to ensure high precision, correct output, and zero errors. If you happen to spot a bug or have a suggestion, please contact us at [email protected] and our team will review it right away.