Beta firmware for the Galaxy S26 Ultra is already on Samsung’s servers.
If you’ve been aggressively refreshing the Samsung Members app on your Galaxy S26 in the hope of seeing the One UI 9.5 beta, you’re wasting your time — although you won’t have to wait much longer. A One UI 9.5 beta build for the Galaxy S26 Ultra has appeared on Samsung’s Korean and US update servers, which is typically the last step before the company opens registrations.
Samsung hasn’t announced the beta or a launch date, but its last point-five update, One UI 8.5, opened to testers on December 8 2025. One UI 9.5 is expected to launch with the Galaxy S27 early in 2027, so a beta release is definitely imminent. If you’re interested, signing up will work the same way as last time: register in Samsung Members, then download the beta from your phone’s settings once it’s available. That is, provided you live in one of six countries — Germany, India, Poland, South Korea, the UK or the US — and own the right phone.
The build that’s been spotted is firmware version S948BXXU6ZZK3, and it’s for the S26 Ultra only, though other S26 phones and servers will almost certainly get the beta. Enthusiast site SammyGuru also expects the S25 series, Z Fold 8 and Z Flip 8 to get the beta as well. Even if you have an S26, though, you may miss out if you bought it through a carrier. The One UI 8.5 beta was only available for unlocked phones in the US, and users with a carrier-locked S26 will probably have to wait for the stable release.
When the beta is likely to open
Samsung opened the One UI 8.5 beta on December 8, 2025, for the Galaxy S25, S25+ and S25 Ultra, but not everyone got it on day one: Owners in Poland and India had to wait until the second beta build on December 22. Samsung launched One UI 8.5 on the Galaxy S26 at its February 2026 Unpacked event, and released a beta for the Galaxy S24 series, Z Fold 6, Z Flip 6, S25 FE, S24 FE and Galaxy Tab S11 in late March.
The One UI 9.0 beta rolled out on May 13, and the stable version released with the Galaxy Z Fold 8 and Z Flip 8 on July 22, in step with Google’s Android 17 release. One UI 9.5 is still based on Android 17, putting it in the same mid-cycle slot 8.5 filled last year and timed for the next Galaxy S phones. As of writing, Samsung hasn’t announced a date for the S27’s Unpacked event, though it’ll probably mirror recent years and fall somewhere in January or February.
Enthusiast site SammyFans has pencilled in early December for the beta, while SamMobile thinks registrations could open in November. Both sites are working from a single previous point-five release, though; the S26’s Ultra build sitting on Samsung’s servers is a far better indication that a beta is imminent.
How to sign up
To sign up for the beta, you’ll need a Samsung account and the Samsung Members app, which you can download from the Galaxy Store or Google Play. Once the beta itself goes live, you’ll simply need to open Samsung Members, tap the One UI 9.5 banner or beta card on the home screen and select Registration for One UI Beta Program. If your phone and country qualify, Samsung will enrol you. From there, head to Settings > Software update > Download and install to get the beta. Samsung rolls builds out gradually, so don’t panic if it doesn’t show up immediately.
Before installing the beta, you should update all your apps and back up your phone to a computer with Smart Switch, since beta software can corrupt your data. If you come across any bugs, you can report them through Samsung Members > Participated Beta test > Beta feedback > Send feedback.
Exiting the beta is the more awkward part. You can withdraw by navigating via Samsung Members > Settings > Beta program settings > Withdraw from beta program, but that doesn’t remove the beta build itself. Instead, you’ll need to plug your phone into a computer and use Smart Switch to run a Downgrade, which will wipe everything you’ve done during testing. If you choose to stay on the beta, you’ll get the finished One UI 9.5 as a normal update, whenever that is. So, if your S26 is your only phone and you don’t keep regular backups, it’s worth sitting this one out and waiting for the stable release.
