Hi Freegris,
Short answer: To make a checkbox readonly or disabled you would need to write a custom script. If you are at this skill level, leave this question open for others and comment that you are looking for the code.
I’m not sure of your particular use-case for wanting a readonly checkbox. If you are creating a form that users need to fill out, I encourage you to think about the user experience of having a read-only checkbox.
- An input that is read-only will not change in visual appearance – You can guarantee that users will click on the checkbox and think it’s broken when they are unable to select anything.
- Depending on your theme, even disabled labels may not visually change appearance.
- Is it even necessary to show a user a field that is disabled? Would it be that difficult/expensive to edit the form or create a new one that doesn’t have the field in the first place?
If you need this checkbox for some users but not others (based on segmentation or a previous field selection), I highly recommend implementing Conditional Logic or a Dynamic Field instead. Basically, only display the checkbox if it’s necessary for the user to fill out. Search on WordPress Plugins for ‘Conditional Logic’, ‘Dynamic Field’, or ‘Contact Form 7 Logic’ to see the various plugins.