Surface Duo's August 2021 Android security and firmware update is here

Surface Duo March2021 Update
Surface Duo March2021 Update (Image credit: Daniel Rubino / Windows Central)

What you need to know

  • The Surface Duo August 2021 Android security and firmware update has arrived.
  • It's 40.22MB and brings the build number up to 2021.721.41.
  • The changelog for the update is now live and posted below.

It's that special time of the month again when Surface Duos get their regularly scheduled updates. This time around, it's another standard security-and-firmware-fueled month without any major bells or whistles, as indicated by the 40.22MB size. The changelog is live on Microsoft's site (opens in new tab), meaning we know exactly what's in the forty-megabyte package, which brings the Surface Duo up to build number 2021.721.41 (for North America).

Update: The changelog is now available. This update is merely installing the Google security patch for August 5th.

  • 2021.721.41 (North America)
  • 2021.721.43 (Europe)
  • 2021.721.42 (AT&T Locked Device)
  • Addresses scenarios outlined in the Android Security Bulletin - August 2021.

As is usual with these updates, security is addressed, helping keep the device free of critical vulnerabilities. Furthermore, the device's update says it "improves the performance and stability" of the Duo, though that's just a way to reiterate the security item in this month's particular instance.

One thing that's not in the update is Android 11, to the disappointment of some users over on Reddit.

Don't forget the Surface Duo 2 is on the horizon. As you might expect, Windows Central readers are pretty darn excited for it, having voted it as their most anticipated upcoming Surface device.

Robert Carnevale

Robert Carnevale is the News Editor for Windows Central. He's a big fan of Kinect (it lives on in his heart), Sonic the Hedgehog, and the legendary intersection of those two titans, Sonic Free Riders. He is the author of Cold War 2395. Have a useful tip? Send it to

  • Really disappointed with how minimal the post-launch updates and improvements have been.
  • At this point, Android 11 is so close, it would be pointless to spend a lot of resources on Android 10.
  • Thank goodness it "improves the performance and stability". Should be pretty darn performant and stable by now, considering that's what all the updates have been.
  • 😂 Good one sir!
  • The Duo is very stable now brotha. If yours is unstable you Hawa bad umit.
  • I don't really expect much in the form of updates until version 2 comes out. Realistic expectations keep me calm. There is the argument that a realistic expectation would've been that Microsoft made more progress with updates after Duo was released, but do we know if that was possible? I'm not sure, but if Microsoft poured most of their resources into version 2 and Android 11 does that mean the experience will be greatly improved, or we will be starting over at square 1?... A lot of questions, but only time will tell. 🤔🤷🏾‍♂️
  • Would be good if they could update the launcher to get feature parity with the version available for other Android handsets... Would also be good if To Do tasks with due dates or reminders could get added to the Outlook Calendar just like Samsung do with their Calendar app... Would also be great if they could add a movies app so I could watch films purchased in the Microsoft store... And before anyone mentions it movies anywhere is not available outside the good old USA... Oh and the Android 11 update would be great too, thanks...
  • I wish Microsoft would release a Movies and TV app, too. While I have access to the Movies Anywhere app, only about half of my content is actually available. I hoped they would at least bring in Groove Music pre-installed on Duo, but that doesn't seem to be something they're interested in. It would at least give the Duo a bit more appeal for those that utilize those apps on PC or Xbox.
  • I hate to be the bearer of bad news, but duo is going to have minimal improvements with android 11. I want to keep people's android 11 expectations in check. Please fast trust me when I say it's not going to do what people think it will do.
  • I feel the same way. But you know what? In 2-4 months we'll know!
  • Where the F is Android 11..... ohhh its waiting for the Surface Duo 2! lol
  • I'm running Android 12 on my Pixel 4a 5G...
  • The first Duo is in Microsoft’s eyes a test device to feel out what the consumer want from the form factor. It is also a test device for the potential buyers of comming Duo on what to expect from Microsoft. I think Microsoft is failing in that second part by not giving anything but the bare minimum to the current Duo owners.
  • Has anyone noticed a faster battery drain after this update?