Samsung Is Already Testing One UI 9.5 on the Galaxy S26, Even as One UI 9 Is Still Rolling Out

Samsung has started internal testing of One UI 9.5 on the Galaxy S26 series, according to a September 30 report. A Korean test build carrying firmware S948NKSU4CZIG has turned up, and this is strictly an internal development build rather than a public beta, first spotted by tipster Tarun Vats . It follows earlier sightings of One UI 9.5 test firmware ending in CHZ1, and separate reports of a real One UI 9.5 build already running on Galaxy S26 hardware, so several different development builds have surfaced over the past couple of months, which is normal for this stage of Samsung’s internal testing cycle.

The build itself confirms that One UI 9.5 development is actively underway, but the version number alone doesn’t reveal what’s actually in it. At this point, these internal builds are most likely being used for bug fixing, performance tuning, stability work, compatibility testing, and laying groundwork for new features, rather than showcasing anything final. The latest report specifically notes that the current build doesn’t reveal any significant new features yet.

One UI 9.5 is expected to stay within the Android 17 generation rather than jumping to Android 18, with some tracking reports tying it to Android 17 QPR2, though Samsung hasn’t confirmed that association, so it’s best treated as unconfirmed for now. Nothing about the feature set is official either; SamMobile has said the early S26 firmware hasn’t revealed a full feature list yet, though One UI 9.5 is expected to be a more substantial update than a routine maintenance release, based on how the One UI 8.5 cycle played out.

A Galaxy S26 beta for One UI 9.5 is expected, though Samsung hasn’t announced a program yet. Current reporting points to late 2026, possibly around the end of November or December, and it could arrive earlier than the One UI 8.5 beta did since development appears to have started sooner this year.

Samsung’s usual pattern backs up that last line: the Galaxy S26 launched with One UI 8.5, and One UI 9 later became the major Android 17 release, so the Galaxy S27 series is widely expected to debut with One UI 9.5. That’s still an expectation rather than anything Samsung has confirmed.

The timing is notable mainly because Samsung only just kicked off the wider One UI 9 rollout, which began on September 16 for the Galaxy S26, S26+, and S26 Ultra and has since reached S26 beta testers in India and Europe. In other words, Samsung is developing One UI 9.5 while One UI 9 itself is still being distributed.

M Adnan Akram

M Adnan Akram is the founder and lead writer at Phoonomo, covering mobile technology with a primary focus on Apple and the broader smartphone industry, alongside emerging developments in AI. He follows product launches, spec leaks, and industry trends closely to keep readers informed with timely updates.