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ironhak

Member

Registered: 2025-08-10

Posts: 88

KDE Plasma Inconsistent Fonts across apps

Hello

I’m on KDE Plasma and I’m running Breeze with default fonts (i.e. no theming customizations applied). There are some apps where the font looks different, here are some examples:
https://i.imgur.com/iLCXH20.png
as you see, apps on the right have the same (even Timeshift that is running as root and it’s a gtk app), while apps on the left (QuodLibet and Qalculate) have a different font…

How can i fix this? Thanks

Last edited by ironhak (2026-07-06 12:27:20)

seth

Member

From: Won't reply 2 private help req

Registered: 2012-09-03

Posts: 76,905

Re: KDE Plasma Inconsistent Fonts across apps

as you see

No I don't - can you please explain why you think those are different fonts?
Not all typically distinct glyphs are present on either side but the ones that are there are the same (esp. note the different extents between "b" and "t" in "Subtiltle" and "boot") - looks Source Sans Pro?

Also please don't embed huge images, edit the post and replace the image w/ a (thumbnail and) link.

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ironhak

Member

Registered: 2025-08-10

Posts: 88

Re: KDE Plasma Inconsistent Fonts across apps

Please see here: https://imgur.com/2Ar3AgX
maybe it's same font but on some apps it's larger...

seth

Member

From: Won't reply 2 private help req

Registered: 2012-09-03

Posts: 76,905

Re: KDE Plasma Inconsistent Fonts across apps

Either you're using different configurations (which is highly unlikely) or there's different DPI perception by those clients.

tr '\0' '\n' < /proc/$(pidof dolphin)/environ
tr '\0' '\n' < /proc/$(pidof qalculate-qt)/environ

X11 or wayland? Are some of those clients xwayland ones, https://wiki.archlinux.org/title/Waylan … plications ?

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ironhak

Member

Registered: 2025-08-10

Posts: 88

Re: KDE Plasma Inconsistent Fonts across apps

Im on wayland. Here is the ouput of that command

HOME=/home/ironhak
LANG=en_US.UTF-8
LOGNAME=ironhak
PATH=/usr/local/bin:/usr/bin:/bin:/usr/local/sbin:/usr/bin/site_perl:/usr/bin/vendor_perl:/usr/bin/core_perl
SHELL=/bin/bash
USER=ironhak
XDG_DATA_DIRS=/home/ironhak/.local/share/flatpak/exports/share:/var/lib/flatpak/exports/share:/usr/local/share:/usr/share
XDG_RUNTIME_DIR=/run/user/1000
DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/1000/bus
DEBUGINFOD_URLS=https://debuginfod.archlinux.org 
DESKTOP_SESSION=/usr/share/wayland-sessions/plasma.desktop
DISPLAY=:0
GTK2_RC_FILES=/etc/gtk-2.0/gtkrc:/home/ironhak/.gtkrc-2.0:/home/ironhak/.config/gtkrc-2.0
GTK_RC_FILES=/etc/gtk/gtkrc:/home/ironhak/.gtkrc:/home/ironhak/.config/gtkrc
ICEAUTHORITY=/run/user/1000/iceauth_xDpNAw
KDE_APPLICATIONS_AS_SCOPE=1
KDE_FULL_SESSION=true
KDE_SESSION_UID=1000
KDE_SESSION_VERSION=6
LANGUAGE=en_US
LC_MEASUREMENT=it_IT.UTF-8
LC_PAPER=C
LC_TIME=en_SE.UTF-8
MAIL=/var/spool/mail/ironhak
MOTD_SHOWN=pam
PAM_KWALLET5_LOGIN=/run/user/1000/kwallet5.socket
PWD=/home/ironhak
QT_WAYLAND_RECONNECT=1
SESSION_MANAGER=local/home:@/tmp/.ICE-unix/1526,unix/home:/tmp/.ICE-unix/1526
VSSCRIPT_PATH=/usr/lib/python3.14/site-packages/vapoursynth/libvsscript.so
WAYLAND_DISPLAY=wayland-0
XAUTHORITY=/run/user/1000/xauth_ZyyrIq
XDG_CONFIG_DIRS=/home/ironhak/.config/kdedefaults:/etc/xdg
XDG_CURRENT_DESKTOP=KDE
XDG_MENU_PREFIX=plasma-
XDG_SEAT=seat0
XDG_SEAT_PATH=/org/freedesktop/DisplayManager/Seat0
XDG_SESSION_CLASS=user
XDG_SESSION_DESKTOP=KDE
XDG_SESSION_ID=2
XDG_SESSION_PATH=/org/freedesktop/DisplayManager/Session1
XDG_SESSION_TYPE=wayland
XDG_VTNR=2
XKB_DEFAULT_LAYOUT=it
_JAVA_AWT_WM_NONREPARENTING=1
MANAGERPID=1274
MANAGERPIDFDID=252
INVOCATION_ID=6d33e70b0a1d4e6ca5d881c726724745
JOURNAL_STREAM=10:20898
SYSTEMD_EXEC_PID=1540
MEMORY_PRESSURE_WATCH=/sys/fs/cgroup/user.slice/user-1000.slice/user@1000.service/session.slice/plasma-plasmashell.service/memory.pressure
MEMORY_PRESSURE_WRITE=c29tZSAyMDAwMDAgMjAwMDAwMAA=
XDG_ACTIVATION_TOKEN=kwin-23
bash: /proc//environ: No such file or directory

seth

Member

From: Won't reply 2 private help req

Registered: 2012-09-03

Posts: 76,905

Re: KDE Plasma Inconsistent Fonts across apps

bash: /proc//environ: No such file or directory

Either dolphin or qalculate-qt wasn't running at the time

Are some of those clients xwayland ones, https://wiki.archlinux.org/title/Waylan … plications ?

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ironhak

Member

Registered: 2025-08-10

Posts: 88

Re: KDE Plasma Inconsistent Fonts across apps

it was qualculate not running

HOME=/home/ironhak
LANG=en_US.UTF-8
LOGNAME=ironhak
PATH=/usr/local/bin:/usr/bin:/bin:/usr/local/sbin:/usr/bin/site_perl:/usr/bin/vendor_perl:/usr/bin/core_perl
SHELL=/bin/bash
USER=ironhak
XDG_DATA_DIRS=/home/ironhak/.local/share/flatpak/exports/share:/var/lib/flatpak/exports/share:/usr/local/share:/usr/share
XDG_RUNTIME_DIR=/run/user/1000
DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/1000/bus
DEBUGINFOD_URLS=https://debuginfod.archlinux.org 
DESKTOP_SESSION=/usr/share/wayland-sessions/plasma.desktop
DISPLAY=:0
GTK2_RC_FILES=/etc/gtk-2.0/gtkrc:/home/ironhak/.gtkrc-2.0:/home/ironhak/.config/gtkrc-2.0
GTK_RC_FILES=/etc/gtk/gtkrc:/home/ironhak/.gtkrc:/home/ironhak/.config/gtkrc
ICEAUTHORITY=/run/user/1000/iceauth_xDpNAw
KDE_APPLICATIONS_AS_SCOPE=1
KDE_FULL_SESSION=true
KDE_SESSION_UID=1000
KDE_SESSION_VERSION=6
LANGUAGE=en_US
LC_MEASUREMENT=it_IT.UTF-8
LC_PAPER=C
LC_TIME=en_SE.UTF-8
MAIL=/var/spool/mail/ironhak
MOTD_SHOWN=pam
PAM_KWALLET5_LOGIN=/run/user/1000/kwallet5.socket
PWD=/home/ironhak
QT_WAYLAND_RECONNECT=1
SESSION_MANAGER=local/home:@/tmp/.ICE-unix/1526,unix/home:/tmp/.ICE-unix/1526
VSSCRIPT_PATH=/usr/lib/python3.14/site-packages/vapoursynth/libvsscript.so
WAYLAND_DISPLAY=wayland-0
XAUTHORITY=/run/user/1000/xauth_ZyyrIq
XDG_CONFIG_DIRS=/home/ironhak/.config/kdedefaults:/etc/xdg
XDG_CURRENT_DESKTOP=KDE
XDG_MENU_PREFIX=plasma-
XDG_SEAT=seat0
XDG_SEAT_PATH=/org/freedesktop/DisplayManager/Seat0
XDG_SESSION_CLASS=user
XDG_SESSION_DESKTOP=KDE
XDG_SESSION_ID=2
XDG_SESSION_PATH=/org/freedesktop/DisplayManager/Session1
XDG_SESSION_TYPE=wayland
XDG_VTNR=2
XKB_DEFAULT_LAYOUT=it
_JAVA_AWT_WM_NONREPARENTING=1
MANAGERPID=1274
MANAGERPIDFDID=252
INVOCATION_ID=6d33e70b0a1d4e6ca5d881c726724745
JOURNAL_STREAM=10:20898
SYSTEMD_EXEC_PID=1540
MEMORY_PRESSURE_WATCH=/sys/fs/cgroup/user.slice/user-1000.slice/user@1000.service/session.slice/plasma-plasmashell.service/memory.pressure
MEMORY_PRESSURE_WRITE=c29tZSAyMDAwMDAgMjAwMDAwMAA=
XDG_ACTIVATION_TOKEN=kwin-122

About xwayland, i don't really know....

seth

Member

From: Won't reply 2 private help req

Registered: 2012-09-03

Posts: 76,905

Re: KDE Plasma Inconsistent Fonts across apps

About xwayland, i don't really know....

Well… figure. See the link I posted for how to go about that. The process environment doesn't explain diverging DPIs.

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ironhak

Member

Registered: 2025-08-10

Posts: 88

Re: KDE Plasma Inconsistent Fonts across apps

I tried and QuodLibet is not a xwayland since it does not get detected by xwininfo

seth

Member

From: Won't reply 2 private help req

Registered: 2012-09-03

Posts: 76,905

Re: KDE Plasma Inconsistent Fonts across apps

At least qalculate seems to have custom font settings, https://github.com/Qalculate/qalculate-qt/issues/195

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ironhak

Member

Registered: 2025-08-10

Posts: 88

Re: KDE Plasma Inconsistent Fonts across apps

At least qalculate seems to have custom font settings, https://github.com/Qalculate/qalculate-qt/issues/195

Thanks... For Qualculate i was using the gtk version, once switched to qt the problem went away.

And QuodLibet is GTK so i think the problem stems from that. Specifically from GTK3 apps that gets themed with Breeze GTK theme, while GTK4 don't get themed at all so you don't even notice.

seth

Member

From: Won't reply 2 private help req

Registered: 2012-09-03

Posts: 76,905

Re: KDE Plasma Inconsistent Fonts across apps

Ah, that explains at least some of it, though I was under the impression KDE would write you a GTK configuration, https://wiki.archlinux.org/title/GTK#Examples

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ironhak

Member

Registered: 2025-08-10

Posts: 88

Re: KDE Plasma Inconsistent Fonts across apps

Ah, that explains at least some of it, though I was under the impression KDE would write you a GTK configuration, https://wiki.archlinux.org/title/GTK#Examples

Strange enough... I changed my Plasma font from the default one Noto Sans to a custom one (Dejavu) and now fonts are the same on all apps... And this happens with all other custom fonts i tried... That mismatch happens only with Noto Sans...

seth

Member

From: Won't reply 2 private help req

Registered: 2012-09-03

Posts: 76,905

Re: KDE Plasma Inconsistent Fonts across apps

But the "mismatch" was the size, not the family??

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ironhak

Member

Registered: 2025-08-10

Posts: 88

Re: KDE Plasma Inconsistent Fonts across apps

But the "mismatch" was the size, not the family??

Yes apparently it was the sizing when using Noto Sans

seth

Member

From: Won't reply 2 private help req

Registered: 2012-09-03

Posts: 76,905

Re: KDE Plasma Inconsistent Fonts across apps

Ok, but how can merely changing the family fix mismatched sizes?
Does noto sans still display this problem?
Is this https://archlinux.org/packages/extra/any/noto-fonts/ ?

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