A ringtone from a video usually takes three apps: one to download the video, one to pull out the sound and one to trim it. The ICANDL ringtone maker does all three from the video link, in the browser. You pick the seconds you want and get a file your phone accepts.

Step 1: load the video

Copy the link of a public video. On Instagram, TikTok and Facebook it's under Share, then Copy link. On X, tap the share icon and choose Copy link.
Open the ringtone maker, paste the link and tap Download.
After a few seconds an audio player appears with the video's sound.

Step 2: mark the part you want

Play the sound. When it reaches the part you like, tap "Start here".
Keep listening and tap "End here" where the ringtone should stop.
Or type the seconds into the Start and End boxes. Decimals such as 12.5 work.
Tap "Play part" to hear only the selection. Adjust until it sounds right.

The line under the buttons shows the length. MP3 ringtones can be up to 60 seconds and M4R ringtones up to 40, which is the iPhone limit. Most good ringtones are 15 to 30 seconds anyway.

Leave "Fade in and out" ticked unless you want a hard cut. It softens the first half second and the last second.

Step 3: save it

Pick the format and tap "Download Ringtone".

MP3 (Android) works with every Android phone and most other devices.
M4R (iPhone) is Apple's ringtone format.

Set it on Android

Open Settings, then Sound (or Sound and vibration), then Phone ringtone.
Choose the option to add a ringtone from your files. It's often a plus button or "From device".
Pick the MP3 from the Downloads folder.

Menu names change between phone makers. On some phones you can also long press the MP3 in the file manager and choose "Set as ringtone".

Set it on iPhone

iPhone doesn't let you set a ringtone from the Files app. There are two working ways.

With a computer: connect the iPhone by cable. On a Mac, open Finder, select the iPhone in the sidebar and drag the M4R file onto its window. On Windows, open iTunes, select the device and drag the file into Tones under On My Device. Then go to Settings, Sounds and Haptics, Ringtone on the iPhone.

Without a computer: download the MP3 instead, import it into Apple's free GarageBand app, then use Share and choose Ringtone. GarageBand limits ringtones to 30 seconds. The step-by-step version is in how to save Instagram Reel audio as a ringtone.

Good to know

Only public videos work. Private accounts and friends-only posts can't be read.
The ringtone has the video's own sound. If someone talks over the music, the voice is in it too.
ICANDL doesn't store files. A song as your own ringtone is personal use; sharing the file is a different matter.

Need the full soundtrack instead of a clip? See downloading audio as MP3 or WAV. For TikTok sounds there is also TikTok to MP3.