Back to Blog home

Sailfish OS 4.5 Struven Ketju

In the late 19th Century, even before the invention of the SatNav, astronomers were uncertain about the exact size and shape of the earth. Maps existed of course, and the earth was understood to be ellipsoid, but the exact size and shape were unknown. Struven Ketju, or the Struve Geodetic Arc is a series of many hundreds of observation stations that stretches from the southern tip of Ukraine to the northern tip of Norway, through ten countries but with its longest stretch running through Finland. Named after its instigator Friedrich Georg Wilhelm von Struve, Struven Ketju allowed the first accurate measurement of a meridian arc, and from that the exact size and shape of the earth to be established. It’s also included on the World Heritage List, and therefore our chosen name for the Sailfish OS 4.5 Struven Ketju release.


At Jolla we’ve always aimed for at least three Sailfish OS releases per year. But the release process comes with its own overheads, and the Sailfish OS Vanha Rauma 4.4 release in March was a big update, including support for the Xperia 10 III in May. So since then we’ve been trying something slightly different: smaller, more incremental releases building on the Sailfish OS Vanha Rauma 4.4 base. The result is that although there’s been a big gap between then and now, we nevertheless pushed out a total of five updates last year:,,, and We will continue to tweak our approach to get the best releases out to you as quickly as possible. 

To celebrate the new release, we are offering Sailfish X at a reduced price of €39.90 from Jolla shop!

But let’s talk about what we’re all here for: Sailfish OS 4.5 Struven Ketju

Sailfish OS 4.5 Struven Ketju is, an impressive combination of updates and improvements. We’ve improved both the foundations and the experience, especially in the area of our unique Android AppSupport technology. We’ve addressed many of the paper cut issues that the community has raised over the years, such as connectivity improvements, improved Bluetooth scanning and audio controls support, refined keyboard layouts, improved account sign-in flow, better Android notification integration and increased browser compatibility, to name a few. 

The headline area of improvement for Android AppSupport is the major update to Android 11. This is an over-the-air update for all our officially supported devices, there’s no need to reflash your phone. With Android 11 expected to be supported by Alphabet until at least 2024, this update ensures there will be no gaps in security-patches or support. 

Android AppSupport is a key pillar in ensuring you have access to wider technologies and services on your phone, making it more compliant for everyday use. Android AppSupport gives you the best access, with the best integration, while also giving you full control over how deeply you want to integrate into the Android ecosystem. 

This control is one of the things that we think makes Sailfish OS so special: purists you can go fully native, using only the many excellent Sailfish apps that are available. If you want Android applications support without having to tie yourself into proprietary ecosystems, you can do that too by installing AppSupport and the apps you desire from your preferred App stores. A step beyond that, installing microG services on your AppSupport enabled phone will give you access to the broadest possible set of Android applications and services without having to sign up for a Google account. Finally, if you want full access to services such as those provided by Google , you can do even that by installing Google Mobile Services as discussed in the forum. 

On Sailfish OS, the decision is entirely yours, and it’s a key part of Jolla’s approach: your device, your choices, your control.

The update to Android 11 brings with it a huge set of improvements to the Android AppSupport integration. From the Android side, new privacy features mean better separation between Android apps, with scoped storage now applied also to external media, one-time permissions support, and tighter restrictions on background location access, to name a few. Our efforts have resulted in important enhancements to the security and stability of AppSupport.

Something which I’m personally proud of is that we now have much improved audio integration, which means that when the user plugs in a headset while a videocall is ongoing, for example, the Android side reacts correctly. User interface sound effects and vibrations are handled in Sailfish OS making audio behaviour unified between Android and native applications. For example previously UI sound effect files would be opened in the Android side, output stream created and audio written through the stream, eventually reaching PulseAudio. Instead of doing all these complicated steps in Android the feedback request is passed to host side and the effect is handled by the Non-Graphical Feedback Daemon (ngfd), so UI feedback clicks are now the same in Android and Sailfish OS and controlling their playback is done from single location in Sailfish OS settings.

We now support also per-application audio streams, meaning that we have separate audio streams for apps on the host side for the first time. Instead of grouping multiple application audio streams by type, we now separate the audio streams by the application, allowing for example per-application volume control in Sailfish OS side if wanted. This is a really cool thing considering Android’s audio architecture.

As you can see, we’ve made many subtle but deep changes to Android AppSupport leading to numerous small, but life-improving, changes. We’re certain you’ll appreciate them even more over time when while using your device.

Outside of Android AppSupport, our commitment to giving you the best access to your device also means we’ve been publishing new APIs for public use by developers. We’ve added access to ten new APIs for the 4.5 Struven Ketju release, including things that many developers have been asking for such as Sailfish Secrets for managing private data, QtLocation for mapping integration, BluezQt for Bluetooth control and Sailfish.Media for audio player integration.


I’m also really happy to see all the improvements on the Sailfish OS side. Damien Caliste has continued to make amazing contributions, which you’ll immediately see when you open the Calendar app. The user interface has been improved with tabs and a brand-new week layout to give you a better overview of upcoming events. There are also numerous background improvements for better syncing with online accounts. 

We’ve added the ability to use an alphanumeric lock code in conjunction with the existing encrypted storage to greatly increase security in the event your device is lost or stolen. 

There is now battery ageing protection, accessible via settings, that applies hysteresis to lengthen the usable life of your battery and ensure that time between charges can be maximised over the lifetime of your phone. We’ve also made numerous fixes to the connectivity systems for mobile, Wifi and to Android AppSupport. 

Overall, the 4.5 Struven Ketju release contains over 700 bugfixes and separately incorporates tens of upstream package updates, all of which make daily use a nicer and more fulfilling experience. Of course, we understand that just like any piece of software there will still be bugs that need fixing, but we’ll continue working with our customers and the community to make sure we’re always making progress in getting them fixed. 



Juho Hämäläinen

Doing hardware adaptation and AppSupport at Jolla. Enjoys gaming and music in free time.


  1. Avatar

    Congrats to SailfishOS 4.5 release! I’ve be running the latest and greatest update since a few days on Xperia 10 II and the overall feel is that a lot of quality fixes had been included making the system even more stable and the Android side snappier.

    Damien’s hard work on the CalDav and calendar integration is awesome and the new look of the UI is a great improvement.

    So many kudos to all at Jolla and the great community helping to make this release possible!

  2. Avatar

    Congrats with a new release! Please consider adding support for Sony Xperia 10 iv – its hard to find previous model cause it is too old.

  3. Avatar

    Congrats for the new release!

    BTW: any plan to have AppSupport buyable for community suppirted phones? (e.g.: so that users of SailfishOS on PinePhones could use it?)

  4. Avatar

    The very reason I am on SFOS is my wish to be as far from google as possible. Instead your main focus is on android compatibility improvements.
    At the same time, search is not available for calendar. Stone age. It was available on iOS a dozen years ago. Considering a move back to iOS. Or lineage. Or ubuntu touch . Rejecting the update for the first time since 2014. Regrets .

    • Avatar

      > The very reason I am on SFOS is my wish to be as far from google as possible. Instead your main focus is on android compatibility improvements.

      There are people (that’s my case), who use non-iOS / non-Google the vast majority of time, but still need to fire up an Android container and microG services once every in a blue moon for the one or two apps that we can’t avoid:
      Banks that still insist on using proprietary android apps for 2FA ; friends who stubornly insist to use some proprietary chat app ; etc.
      Banking apps are specially finicky (evenmore so if you run then atop microG instead of the official Google Play Services).

      So improvements are welcome for those use cases.

      Without Jolla’s AppSupport that would mean we need to carry an extra Android phone and turn it on on these circumstances. Now it’s just starting and stopping a container when the app is needed.

  5. Avatar

    Man, I’m so moved.
    Wrote a native GPS logging app back in SailfishOS 1.1 times, and it’s been working since nine years. It was rejected from JollaStore because it required QTLocation.

  6. Avatar

    stop whining start living (SfOS 4.5 is more stable than ever)

    greetingz from Xperia 10 II

  7. Avatar

    Android is always stable.Do we need SFOS then?

  8. Avatar

    Have been with jolla more or less from the start with the jolla 1. I upgraded to the sony x when it became available and it was a great phone. Then upgraded to a beta xa2 which os release after release makes ut worse. With this upgrade i can not use the browser without multiple crashes. Cant install warehouse (after doing a factory restore) cant connect to the internet using my carrier when abroad. Its brought jolla from a trustworthy daily driver to something i had to park. My reason for going to jolla years back was to get away from Apple and Google. Ive now decided to use graphine os. Its a shame the quality iff each release from jolla was always top notch. Now the quality team seems to have gone on leave. I hope jolla returns to its values once again.

    • Avatar

      In addition i was unable after 15 attempts to set up email. And the vpn config i have is lost after every reboot. It stopped being something i could trust for daily use. Shame 🙁

  9. Avatar

    updated xperia 10 to 4.5.
    all works nice and smooth
    thanks !

  10. Avatar


    I recently acquired Sony Xperia 10 iii and I cannot get multimedia text messages on T-Mobile network in the USA. To no avail, I manually entered T-Mobile multimedia settings on my Xperia 10 iii. I suspect that the issue that I am experiencing is by virtue of Sailfish OS. If anyone else is experiencing the same, let me know. Also, the next update needs to address the issue that I am having.

  11. Avatar

    Is AppSupport still only limited to the Sony Xperia line? What would be required to open up AppSupport for more phones?

  12. Avatar

    Great improvement, thanks Jolla!

  13. Avatar

    Update went almost perfect; Xperia XA2 seems little smoother, faster.
    One issue: my openvpn entries were gone; had to reinstall them one by one.
    But all-in-all: thanks, grosse Klasse 🙂

  14. Avatar

    Vieläkö Sailfish-käyttistä kehitetään tuleville älypuhelimille vai jääkö kehittely nyt Sony Xperia 10 III:een?

  15. Avatar

    Any new$ regarding Tablet refund$?

  16. Avatar

    Onko tosiaan mitään uusiapuhelinmalleja “putkessa”? -tuota 10 III:sta ei enää kaupoista löydy…

  17. Avatar

    Hello together, does anybody know what happens with Jolla ? No news, no updates, but I hope not “no hope” ?

Submit a Comment