How do you create an iPhone ringtone from a song?

What Apple says

Apple's support article Create a custom ringtone on your iPhone (published 2025-05-22, read 2026-10-03) makes ringtones in GarageBand: you bring an audio file in from the Files app, trim it, then use Share and Ringtone from the My Songs view. The article says ringtones "can be up to 30 seconds long", and that if a ringtone is longer, GarageBand offers to "shorten the ringtone automatically". It does not say which end it shortens.

Apple's GarageBand guide Import audio and MIDI files (read 2026-10-03) lists the audio files it takes: "AIFF, WAV, Apple Loops, AAC, and MP3". It also says an imported file "is converted to a 44.1 kHz sample rate, 16-bit depth format if the original format is different".

A file you download in Safari ends up in the Downloads folder of the Files app, according to Apple's Where to find downloads on your iPhone or iPad (published 2025-12-17, read 2026-10-03). That is where GarageBand's file browser can pick it up.

We did not test GarageBand or a physical iPhone. Everything measured below is about the file the cutter makes.

How we tested

• Tool: the audio cutter on this site, driven by Playwright 1.63.0 in Chromium 153 on a local copy of the page. We typed a start of 0 and an end between 29.900 and 30.500 s, picked MP3 (128 or 192 kbps) or WAV, and saved each download. One export was repeated in Playwright's iPhone 15 profile (a phone-sized screen and iPhone user agent in Chromium, not Safari).
• Music: 30 seconds (1:00 to 1:30) of Mozart's Symphony No. 40, first movement, played by the Musopen Symphony, public domain on Wikimedia Commons, converted to 44.1 kHz, 16-bit stereo and played twice to make a 60 s file.
• Checks: exact size in bytes; MP3 frames counted one by one; the file decoded with FFmpeg 4.4.2 and its samples counted (44,100 samples = 1 s); the start of the music found by lining the decoded file up with the source.
• Edge: to find the exact limit, we ran the same MP3 encoder the page uses (lamejs) in Node and searched sample by sample for the longest region that still makes a file of 30 s or less, at all four bitrates.

Region length typed vs file length saved

An MP3 file always holds a whole number of frames of 1,152 samples. The cutter's encoder puts 1,105 samples (25.1 ms) of silence before the music and fills the last frame with silence too. So the file grows in steps of one frame (26.12 ms), and it is always a bit longer than the region. A file without a gapless-playback tag, like these, plays all of it, silence included.

The step to the next frame falls between 29.962 and 29.963 s. In Node, with the same encoder, the longest region that kept the file at 1,148 frames (29.989 s) was 1,321,344 samples, which is 29.962 s, at 128, 192, 256 and 320 kbps alike. Typing 29.963 s already adds a frame.

For the 30.000 s MP3, the music itself runs 25.1 ms past the 30 s mark of the file. If something cuts that file at 30.000 s from the start, those last 25.1 ms of music are what goes. We do not know whether GarageBand counts the encoder silence when it checks the length.

WAV has no frames and no encoder silence: every WAV in the test held exactly the samples selected and started the music on the first sample.

File size and phone vs desktop

The WAV is 7.34 times the size of the 192 kbps MP3. Saving WAV means the cut adds no MP3 compression of its own; saving MP3 means the music is compressed once before GarageBand gets it. We did not check what format GarageBand writes the ringtone in. For how much a single MP3 export loses at each bitrate, see Does cutting an MP3 lose quality?

The 0 to 30 s export with a 2 s fade out, saved at 192 kbps in the iPhone 15 profile, was byte for byte the same as the desktop file (720,979 bytes). The cut is done by the page's own code in the browser, so the screen size does not change the result. We did not run it in Safari.

Step by step

1. Open the song in the audio cutter in Safari on the iPhone, or on a computer and move the file to iCloud Drive. The file is read in your browser, not uploaded.
2. Drag the handles or type the start and end so the length shows 29.960 s or less for MP3, or 30.000 s or less for WAV. Press Play region to check it.
3. Set Fade out to 1 or 2 s so the ringtone does not stop dead each time it repeats. Our Android ringtone test measured how loud the end stays with and without a fade.
4. Pick WAV (16-bit PCM), or MP3 at 192 kbps or more, and press Download. In Safari, the file goes to Downloads in the Files app.
5. Follow Apple's GarageBand ringtone steps: bring the file into a track from Files, then Share, Ringtone, Export. The file is then inside Apple's 30 s limit.

Want the ringtone to start on an exact beat? See Can you trim an MP3 to the exact millisecond?

Questions

Do I need an M4R file?

Not for the GarageBand route: Apple's import list is AIFF, WAV, Apple Loops, AAC and MP3, and GarageBand makes the ringtone itself. The cutter saves MP3 or WAV only; it does not write M4R.

Why does the size shown before download not match the file?

For MP3 the page shows an estimate from bitrate times length, counting 1 KB as 1,024 bytes. For WAV the page says the size is exact: it showed 5.13 MB for the 30.500 s region, and the file was 5,380,244 bytes.

Can I use 30.000 s if I pick MP3?

The file will be 30.041 s. Apple says GarageBand shortens a ringtone over 30 s if you tap Continue, but we did not test what it removes. Cutting 29.96 s, or saving WAV, avoids the question.