I have been wanting to use my S25 ultra as a second monitor for my computer, but it's gone. i wanted this back for a long time. even though the screen is kinda small for such activity, it would be nice for me to use my phone as a second monitor for content creation or live streaming. could we have this feature back please?
I never lost the ability to use any phone or tablet in that manner. If you know, you know. Asus has a lovely little app/service called GlideX it provides about a dozen different configurations of connecting PC to phone and monitor #2, even unified monitor where you can maintain normal UI on the s25U but still freely cross from PC to the galaxy screen with the mouse and file moving, whatever you want, it does.
Only issue is afaik, you need a Asus computer to successfully get it there is a server side switch that gives you VIP access if you have Asus and VIP is what enables anything good. It doesn't utilize a single part of Link to Windows, or Dex
You're absolutely right — using your Galaxy S25 Ultra as a second monitor is a super useful feature, especially for creators, multitaskers, and streamers. And yes, Samsung used to support this (through “Second Screen” in the Link to Windows / Samsung Flow ecosystem), but sadly, this feature was discontinued on newer One UI versions and devices.
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Why It’s Gone:
Samsung previously included Second Screen on select Galaxy Tab models (like Tab S7/S8), not phones.
The feature relied on Miracast / WiDi compatibility, which Windows 11 and modern Android versions no longer support well — making it harder to maintain cross-device projection.
Samsung has since focused on DeX, Multi Control, and Phone Link (via Windows) — none of which currently support using the phone as an extended desktop display.
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Can You Get It Back on the Galaxy S25 Ultra?
Unfortunately, Samsung doesn’t officially support Second Screen on phones anymore — and likely never fully did on any model. It was always tablet-exclusive, and no known Good Lock module, Galaxy Store add-on, or developer setting currently brings this feature back to phones in One UI 6 or 7.
But there are workarounds:
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Alternative Workarounds to Use S25 Ultra as a Second Monitor
1. Use Third-Party Apps
You can simulate second monitor behavior using these apps:
A. Spacedesk
Install Spacedesk Viewer on your S25 Ultra
Install Spacedesk Driver on your Windows PC (free from spacedesk.net)
Connect over Wi-Fi or USB tethering
Your phone becomes a fully functional secondary display
B. Duet Display (paid)
Download from Play Store and install the desktop app (Mac/Windows)
Stable, low-latency, and supports touch gestures on the phone
Best for productivity, drawing, or streaming dashboards
2. Samsung DeX with a Twist
DeX itself doesn’t let your phone become a second display, but:
You can connect DeX to a monitor while mirroring something else (like OBS controls) on your phone
It’s not a true "extend desktop" function, but you can manage dual displays in a creative way
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Feature Request?
Yes — it’s 100% valid to request this from Samsung.
Open the Samsung Members app
Go to Get Help > Feedback > Suggestion
Request: “Please bring back Second Screen mode for Galaxy phones, especially Ultra models. Would love to use it as a second monitor for PC like Galaxy Tabs could.”
The more users request it, the better the chance we’ll see it in a future update or as a Galaxy Labs experiment.
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Final Word
You’re not imagining it — the desire for this feature is real and shared by many. While Samsung hasn’t made it official for phones, apps like Spacedesk or Duet Display are excellent replacements right now.
Let me know if you want help setting one up — it only takes a few minutes and works surprisingly well.
