When to Use All Caps
Use all caps for abbreviations and for very short labels. Do not use all caps for sentences, paragraphs or emphasis. All caps means that every letter of the text is a capital letter, LIKE THIS.
This guide shows where all caps is fine, why long text in capital letters is harder to read, what three style guides say about it, and what to use for emphasis instead.
What does all caps mean?
All caps is text written only in capital letters. Other names for it are uppercase, block capitals and block letters.
| Style | Example |
|---|---|
| All caps | SALE ENDS ON FRIDAY |
| Title case | Sale Ends on Friday |
| Sentence case | Sale ends on Friday |
In messages and posts, all caps is read as shouting. A sentence in capital letters sounds angry even when the writer only wanted to be clear.
When is all caps correct?
- Abbreviations and acronyms. NASA, UNESCO, PDF, USA. These are always written in capital letters.
- Official names. A brand or product that writes its own name in capital letters keeps them.
- Code. Names in code that are written in capital letters stay that way when you mention them.
- Very short labels. One or two words on a sign, a button or a table header, such as EXIT or TOTAL.
- Forms that ask for it. Paper forms often ask for BLOCK LETTERS so that handwriting can be read.
The first three cases are the exceptions that Google's developer documentation style guide allows. Its rule is to not use all-uppercase except in official names, in abbreviations that are always written in all caps, and when referring to code that uses all caps.
Why all caps is harder to read
Long text in all caps is harder to read because every word gets the same shape. The CMS Design System, the design system of a United States health agency, explains this in its guidance on text.
- Same height, same shape. In capital letters all letters have the same height, so each word looks like a rectangle. Small letters go up (b, d, k) and down (g, p, y), which gives each word its own outline.
- Slower reading. Without the outline, the eye reads letter by letter, and reading gets slower.
- Harder with dyslexia. The same guidance says all capital letters make words harder to read, particularly for people with dyslexia.
- Screen readers. It also warns that some screen readers read capitalized text letter by letter.
One or two words are not a problem. The effect grows with the length of the text.
What style guides say about all caps
| Style guide | Rule on all caps |
|---|---|
| Microsoft Writing Style Guide | Do not use all uppercase for emphasis. Italic is OK for emphasis if used sparingly |
| Google developer documentation style guide | Do not use all-uppercase, except in official names, abbreviations and code |
| CMS Design System | Use all capital letters sparingly, because of readability and screen readers |
The three guides come from different fields and agree on the main point: capital letters are for short items, not for making a sentence loud.
What to use instead of all caps for emphasis
| Instead of | Write | Why |
|---|---|---|
| DO NOT open the file | Do not open the file | Bold marks the one word that matters |
| IMPORTANT NOTICE FOR ALL USERS | Important notice for all users | A heading is already set apart by its size |
| PLEASE READ THIS CAREFULLY | Please read this carefully | A calm sentence is read more willingly |
Bold or italic on one or two words does the work of capital letters without the shouting. For headings, the choice is between two calmer styles. See the guide on title vs sentence case.
How to fix text typed in all caps
Text typed with Caps Lock on does not have to be typed again. A case converter changes it in one step.
- Paste the text in the Text to convert box.
- Choose Sentence case. Each sentence starts with a capital letter and the rest is in small letters.
- Fix names and abbreviations by hand, then press Copy.
Step 3 is needed because the tool cannot know which words are names. "I LIVE IN LONDON." becomes "I live in london.", so London needs its capital letter back.
Frequently asked questions
- Is writing in all caps rude?
- In messages and posts it is read as shouting, so many people find it rude. For one short label or an abbreviation it is normal.
- Is all caps harder to read?
- For long text, yes. All letters have the same height, so words lose their shape and are read more slowly. One or two words are fine.
- Should headings be in all caps?
- A very short heading can be. For longer headings use title case or sentence case, which are easier to read.
- What can I use instead of all caps for emphasis?
- Bold or italic on the one or two words that matter. The Microsoft Writing Style Guide allows italic for emphasis if it is used sparingly.
- How do I change all caps to normal text?
- Paste the text in a case converter and choose Sentence case or lowercase. In Word, select the text and press Shift+F3.