I'm developing an app that allows users to manage their financial products. This app shows information about accounts, balance, cards, etc. Considering such details are private and sensitive, I'd not want the person next to me to be able to see it.

Q: Is there is a particular font size or some standards/rules for showing such sensitive information?

  • 3
    Not answer, as don’t know the field well enough to be 100% sure, but I’d expect that any such restrictions would conflict with accessibility guidelines/requirements, as some restricted visibility users need to run their systems using significantly larger font sizes than the rest of us.
    – Gwyn Evans
    Commented Sep 14, 2019 at 10:01
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    I'd expect the user, if there's a nosy neighbor, to take their own security measures, like angling the phone away or waiting until they're home to use the app. Commented Sep 18, 2019 at 18:48

3 Answers 3


I don't think there are specific rules regarding this. If the users know the information are going to check is sensitive, it is more up to them to make sure there is no one around. Anyway, if it is a screen with different information, you can have a similar approach to the password fields, hide the content and put a button beside to show it, you can even protect it with a pin code or fingerprint in case more than one user can access to the device.

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  • Thank you for the answer Rocio. In particular I don't want to generate friction to the user to see his own information, as you decide, it's up to him to consider himself. There is some info, with which I can take that precaution, but I wanted to know if I should consider, for example for the balance or the due date of a payment. Commented Sep 13, 2019 at 15:59
  • If you make font size to small you will alienate people above 50. Most of them will need glasses to read it. Also it would be inconvenient to read for young people, the standard is 12-18 (depends who you ask) as the smallest size. Still if you make it 11, some users will have trouble, and it still would not fulfill its function. The solution proposed by rocio is better. It gives a user feel of safety. And if somebody don't need that, make a switch that will block masking in the future.
    – Ada
    Commented Sep 14, 2019 at 14:02
  • Thanks Ada for your answer too. I want to know if there is a top cap to make some info bigger, not smaller. In regards of posible privacy issues. Commented Sep 18, 2019 at 16:38

In some self-service HR software systems, salary or compensation is by default hidden (obfuscated by blurring) on the main page with a button nearby to un-hide (un-blur) the information at the user's convenience. For improved flexibility for the user, you could implement something like this as the global default, but include an option to toggle the behavior in the user settings. Maybe pop up the option on first un-hide, so they become aware of the option and, if they wish, can alter the behavior immediately.

Then you don't need to worry as much about the sensitivity of the information as it relates to your font and size choices and you can just use some font/size choice that's consistent with the rest of your page/site.


I assume 'maximum size' refers to situation that someone nearby may see what's going on on your screen. And that you're design a banking app that requires authorization (pswd/code/fingerprint) to open.

There is definitely no specific rule. All this information appears only if the user intentionally opens it - so it's for him to judge the environment. Even right after installation you're very likely expecting that a banking app will show account balance. Many ATMs allow to show the balance on their much bigger screens.

Just be reasonable and happy designing.

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