I am trying to install Java 9 on Ubuntu 18.04 as I heard it could work as a solution for super small font of Qt Creator.

However, when I type in the terminal:

sudo apt install openjdk-9-jdk

I get the below error:

Unable to locate package openjdk-9-jdk

1 Answer 1


openjdk-9-jdk has been replaced by openjdk-11-jdk in Ubuntu 18.04. To install it open the terminal and type:

sudo apt update  
sudo apt upgrade  
sudo apt install openjdk-11-jdk  

I don't expect this will fix the font size problem because Qt Creator doesn't have any Java version as a dependency.

My fonts in Qt Creator look OK with the following preferences.

  1. Open Qt Creator.

  2. Select Tools -> Options.

  3. From the left pane of the Options window select Text Editor as shown in the below screenshot.

  4. Select Fonts & Colors tab.

  5. Under the Font heading after where it says Family: select Source Code Pro from the dropdown menu as marked by the mouse cursor in the below screenshot. After where it says Size: select 10 from the dropdown menu. Font size 10 is the best font size in my Qt Creator. If the font size still looks too small after continuing through the steps to step 6, select 11 or 12 instead of 10 from the dropdown menu.

  6. Click the Apply button and then click the OK button to save the changes.

enter image description here

  • That worked, even if the font issue with Qt Creator looks unresolved
    – raltok
    Commented Sep 21, 2018 at 9:40
  • 1
    I edited my answer with the steps required to resolve the super small font size problem in Qt Creator.
    – karel
    Commented Sep 21, 2018 at 9:55
  • 1
    I managed to solve the environment as well by enabling "High DPI Scaling", seems OK now
    – raltok
    Commented Sep 21, 2018 at 12:48
  • 1
    this helped my font issues other QT apps like Robo 3T (robomongo)
    – Marconius
    Commented Oct 3, 2018 at 18:27

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