From my understanding:

  1. It had been thought all uppercase (e.g. THIS IS SCREAMING) was hard to read because of the way the eye works.
  2. It is now understood that all uppercase is hard to read just because people aren't used to reading it.

Though this is all academic. When should upper case be used? At the highest level heading, in all levels of headings or what? What about using all upper case in bodies of texts, for example an important sentence?

I thought the benefits were obvious but no ones mentioned them. They are to grab peoples attention and add another tool to achieve levels of visual hierarchy.

  • 5
    I'm not entirely sure this is a UX issue - It's probably more about your corporate 'tone of voice'. Commented Aug 2, 2016 at 7:21
  • 2
    This is a actually typography question so perhaps it needs to be moved to graphicdesign.stackexchange.com/questions/tagged/typography
    – SteveD
    Commented Aug 2, 2016 at 11:25
  • In the Navy. ---
    – aventurin
    Commented Sep 1, 2016 at 18:55
  • 1
    Agree that there is overlap into other forums, but use of typography is one of the main tools in UX and this is about the use of upper case. I like it here.
    – Jonny
    Commented Sep 3, 2016 at 9:49

8 Answers 8


It's down to you to make that decision for your style guide. Take a look at some other organisations guidelines and use them to guide you:

  • Wikipedia has some very clear guidelines on when to use uppercase. For example "Initial capitals or all capitals should not be used for emphasis."
  • BBC say "Our style generally is to minimise the use of capital letters."
  • Mailchimp and The Economist both guide against using uppercase in sentences but both style some of their headings in uppercase.

It's always a judgement call. Ideally, you'd use it as little as possible, preferrably never, because it's harder to read.

However, there are reasons why others compromise. Material design uses all caps for buttons to separate them from other text, as material buttons can have no borders. The consistent height of the letters creates a visual rectangle out of the letters. All caps were traditionally used in SQL because text editors and IDEs used to not delineate between SQL commands and classes in Strings. And, unfortunately, a number of designers choose to sacrifice readability for style.


Its a call, I guess, that you would have to make. Since material design, there are lot of places where the upper case has been used where it doesn't feel like its screaming for attention.

If you would want to use uppercase alphabets, better stick to using them in the highest level heading, imo.

Cheers! :)


Use cases worth pointing out for when to use all upper case:

  • When targeting young children
  • When targeting other near-illiterate audiences
  • When pointing out danger or critical components.
    E.g. see exterior labelling on aircraft, as below.

    enter image description here
  • And as Ken Mohnkern pointed out: Acronyms should be in all caps.
  • Why use all-caps when targeting young children or illiterate audiences?
    – DA01
    Commented Sep 1, 2016 at 18:35
  • @DA01 Because people learn the big letters first. E.g. look at all the ABC toys – they use big letters. Or look at young kids writing their own names. They start out with all caps.
    – bjornte
    Commented Sep 1, 2016 at 21:06
  • but that predates reading. So not really applicable if the intent is people are reading things.
    – DA01
    Commented Sep 1, 2016 at 23:41
  • @DA01 The OP doesn't provide a user story but simply asks when to use upper case. "Bodies of text" is just one of the areas she/he mentions, so seems to me the question is broadly intended. Other people here seem to think so too as they are mentioning interface elements. I would say "learning to read" is an extremely important user story, and at that point using upper case is suitable.
    – bjornte
    Commented Sep 2, 2016 at 5:53
  • When one learns to read they tend to not learn with all-caps. In fact, it's just the opposite. Beginner reader books are specifically upper and lower-case: 4.bp.blogspot.com/-2LECWnRqDv4/T-uuv1r3JMI/AAAAAAAAALM/…
    – DA01
    Commented Sep 2, 2016 at 6:02

You use it when it makes sense to use it. There are no rules for this.

It's usually a typographic/aesthetic call based on the context of the content and where it's being used.

It's easier to say where not to use it: Don't use it for all your body copy BECAUSE OF THE YELLING CONNOTATIONS.

However, for headlines, charts, signage, navigation, headers, captions, etc...all can be valid places for using all-caps (or small caps)

  • As I read this in my head, I heard someone screaming the end of that sentence at me. Commented Sep 1, 2016 at 19:58
  • @maxathousand which makes perfect sense given the context!
    – DA01
    Commented Sep 1, 2016 at 20:15

It's a matter of style.

There are several ways you can differentiate one thing from another, or one thing from a group of things (which may be what you are aiming for).

It's worth looking into theories such as gestalt theory to get an idea of how this works. This set of blogs is one of my favourite introductions to it https://www.smashingmagazine.com/2014/03/design-principles-visual-perception-and-the-principles-of-gestalt/

Using all capitals can be a good way to make a word or set of words standout from a wider group of content (hence the association with shouting). There are several other ways you could also do this using attributes such as colour, size, positioning, weight, common fate (maybe achieved with an animation) etc.

As a rule of thumb, you normally only choose one attribute or method to make something standout otherwise it can look like overkill and standout like a sore thumb, unless you want it to stick out like a sore thumb of course. Notice here that italics was used to differentiate "unless" from the rest of the sentence. Different techniques and combination of techniques have different effects and values, and these can change between cultures and contexts. If I really want something to STICK OUT LIKE A SORE THUMB then I can play around with these.

As a side note you may be interested to know that upper-case refers to the positioning of the drawer that typesetters took their type from. The lower case was more accessible and contains the set that was needed more frequently and quicker. https://en.wikipedia.org/wiki/Letter_case#Terminology


A quick Google search reveals this:

When is it okay to use all caps? All caps are fine in contexts that don’t involve much reading, such as logos, headings, acronyms, and abbreviations. But when your message involves reading, don’t force users to read words with bad shape contrast. The caps lock key is a key that designers should rarely use.


I'm not sure your two assertions at the beginning of the question are accurate. That article, and many others, say that uppercase is hard to read because the outline of every word is rectangular, where lowercase gives every word its own more scannable, glanceable shape.

  • It's a nice citation but is also based on the 'bouma' concept of word shapes which hasn't been shown to be a real thing in terms of readability.
    – DA01
    Commented Sep 1, 2016 at 18:36
  • I wasn't aware. What's this bouma? Edit: It means the shape of a cluster of words. Commented Sep 1, 2016 at 19:46
  • It's a term that was coined to describe "word shapes" with the theory that we 'read' the shapes of words. Alas, this has never been shown to be true.
    – DA01
    Commented Sep 1, 2016 at 20:16

Only acceptable when you are yelling.

To be more specific, when calling attention to specific words or phrases, or emphasizing a labeled element, for example. Or chewing someone out electronically, let's face it.

Also acceptable for use by older parents for everyday communication, no matter how many times you tell them how to turn off caps lock.

  • This does not provide an answer to the question. To critique or request clarification from an author, leave a comment below their post. - From Review
    – Mayo
    Commented Sep 1, 2016 at 14:35
  • Apologies, but with all of the answers already provided, I thought a more whimsical - yet concise and fairly accurate - answer would not be remiss.
    – Mattynabib
    Commented Sep 1, 2016 at 14:38
  • Not a bad idea - to provide levity. But, If you can - expand on your answer. At times I use uppercase on labels and doesn't seem as if I'm yelling. PRICE $100.00 So, there are sometimes one can use UPPERCASE and not be yelling. :-)
    – Mayo
    Commented Sep 1, 2016 at 14:48
  • Is this better?
    – Mattynabib
    Commented Sep 1, 2016 at 14:54
  • definitely whimsical :-)
    – Mayo
    Commented Sep 1, 2016 at 15:05

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