More Galaxy S21 owners in the USA can download May 2025 security update

Samsung has made the latest software update for the Galaxy S21 series more widely available in the USA. The May 2025 security update started rolling out to carrier-locked variants of the S21, S21+, and S21 Ultra earlier this week, and access has now been opened up to owners of unlocked units.

The Galaxy S21, S21+, and S21 Ultra received their final major OS upgrade, One UI 7 (Android 15), about a month ago, and this is the first software update for the three phones since then. Unfortunately, it doesn't include the latest security fixes that started rolling out to newer Galaxy smartphones a couple of days ago.

This update only brings security fixes to the Galaxy S21, S21+, and S21 Ultra, and you can learn more about those fixes here. The Galaxy S21 FE received a similar update near the end of May (the FE model is also eligible for One UI 8).

You can identify the May 2025 update by the build number G99*U1UESFHYE1 and download it over the air from your phone's Settings » Software update menu. You can also find the latest firmware for your S21-series phone in our firmware archive and install it on the phone using a Windows PC.