# VTK - Qt versions poll....
**URL:** https://discourse.vtk.org/t/vtk-qt-versions-poll/8904
**Category:** Announcements
**Created:** [July 7, 2022, 2:03pm UTC](https://discourse.vtk.org/t/vtk-qt-versions-poll/8904 "2022-07-07T14:03:14Z")
**Posts on this page:** 9
**Page:** 1
### Author:  [@DominionSoftware](https://discourse.vtk.org/u/DominionSoftware)
#### Post date: [July 7, 2022, 2:03pm UTC](https://discourse.vtk.org/t/vtk-qt-versions-poll/8904/1 "2022-07-07T14:03:14Z")
I’m about to embark upon a new project using VTK and Qt and wondering what versions of each play well together?
Which versions are any of you using together in a desktop application?
Thanks
Rick
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### Author:  [@mwestphal](https://discourse.vtk.org/u/mwestphal)
#### Post date: [July 7, 2022, 2:07pm UTC](https://discourse.vtk.org/t/vtk-qt-versions-poll/8904/2 "2022-07-07T14:07:13Z")
ParaView ships with Qt 5.15.4 and the most recent version of VTK of course.
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### Author:  [@lassoan](https://discourse.vtk.org/u/lassoan)
#### Post date: [July 7, 2022, 3:18pm UTC](https://discourse.vtk.org/t/vtk-qt-versions-poll/8904/3 "2022-07-07T15:18:41Z")
In 3D Slicer we use Qt-5.15.x, too. We’ll probably switch to Qt-6 in about 6-12 months.
I would recommend to always use the same VTK and Qt versions that ParaView and 3D Slicer is using, as these applications are continuously tested on all Windows, Linux, and macOS by thousands of users on different hardware, so all commonly occurring issues get reported and fixed. This will save you a lot on software support and maintenance.
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### Author:  [@Paulo\_Carvalho](https://discourse.vtk.org/u/Paulo_Carvalho)
#### Post date: [July 9, 2022, 9:52pm UTC](https://discourse.vtk.org/t/vtk-qt-versions-poll/8904/4 "2022-07-09T21:52:48Z")
In my case, Qt 5.12 works well with VTK 9.1.
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### Author:  [@DominionSoftware](https://discourse.vtk.org/u/DominionSoftware)
#### Post date: [July 9, 2022, 10:01pm UTC](https://discourse.vtk.org/t/vtk-qt-versions-poll/8904/5 "2022-07-09T22:01:54Z")
Thanks for all the replies. I’m wonder if anyone has tried 6? I notice the VTK cmake GUI let’s me choose it.
Thanks
Rick
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### Author:  [@mwestphal](https://discourse.vtk.org/u/mwestphal)
#### Post date: [July 11, 2022, 6:44am UTC](https://discourse.vtk.org/t/vtk-qt-versions-poll/8904/6 "2022-07-11T06:44:06Z")
It is supported but without actual testing in the CI, I’d not recommend it.
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### Author:  [@lassoan](https://discourse.vtk.org/u/lassoan)
#### Post date: [July 11, 2022, 2:46pm UTC](https://discourse.vtk.org/t/vtk-qt-versions-poll/8904/7 "2022-07-11T14:46:05Z")
Qt has a pretty bad track record with major updates. After a major update it typically takes at least 5-10 minor releases for the library to become stable and feature-complete again. They are still at just Qt-6.4, so I would not rush the update.
That said, Qt stopped providing long-term support releases for free, so Qt-5.x bugfixes and platform updates are only available if you buy Qt or move to Qt-6.x. So, probably most people will need to update to Qt-6.x within a year or so.
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### Author:  [@mwestphal](https://discourse.vtk.org/u/mwestphal)
#### Post date: [July 12, 2022, 2:15pm UTC](https://discourse.vtk.org/t/vtk-qt-versions-poll/8904/8 "2022-07-12T14:15:15Z")
> [@lassoan](#):
>
> That said, Qt stopped providing long-term support releases for free, so Qt-5.x bugfixes and platform updates are only available if you buy Qt or move to Qt-6.x.
KDE has a open fork that backport Qt6 patches, it works great.
> **[Announcing KDE's Qt 5 Patch Collection](https://dot.kde.org/2021/04/06/announcing-kdes-qt-5-patch-collection)**
>
> As Qt 5 support is drawing to a close, and we shift to Qt 6, we need to ensure that KDE products are as reliable as ever. To this end, KDE will be maintaining a set of patches with security and functional fixes so that we can enjoy good KDE Software...
> pacman -Ss qt5-base
> extra/qt5-base 5.15.5+kde+r170-1
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### Author:  [@lassoan](https://discourse.vtk.org/u/lassoan)
#### Post date: [July 12, 2022, 3:44pm UTC](https://discourse.vtk.org/t/vtk-qt-versions-poll/8904/9 "2022-07-12T15:44:26Z")
Thanks for the information, this can be useful (although probably patches are not provided for Windows and macOS specific issues, and most likely pre-built binary pckages only available for KDE).