Sentence case is a capitalisation style for headings and interface text that capitalises the first word and any proper nouns, and leaves everything else in lower case, as a sentence would. “How to renew your passport” is in sentence case. “How to Renew Your Passport” is in title case.
Title case comes from publishing tradition, where style manuals set rules for which words take capitals. It looks formal but brings decisions with it: whether “to”, “with” or “between” count as minor words, and what to do after a hyphen or colon. Sentence case avoids most of those decisions. It’s long been common in British newspaper headlines and is now the default in many digital style guides, including Microsoft’s and GOV.UK’s. Apple’s guidelines still use title case for many interface elements, so neither style is universal.
The same rule can apply to buttons, navigation, labels, form fields and error messages, not only headings.
Why it matters for content
Consistent capitalisation helps a product or publication feel coherent. Sentence case reduces visual noise and lets wording, hierarchy and design carry emphasis. It’s a down-to-earth accessibility practice: familiar capitalisation, without making every word announce its importance. The benefit varies by reader and context, so it belongs alongside clear wording and good heading structure, not in place of them.
It can also puncture the pomposity of title case. A heading doesn’t need a capital on every word to deserve attention. In his article Making a case for letter case, Dropbox writer John Saito explains that the company deliberately uses sentence case to feel “natural and approachable”. That friendliness is a reason to choose it, distinct from any accessibility benefit.
It also reduces editorial friction. Writers don’t need to decide whether short prepositions, conjunctions or infinitives deserve capitals. Translation teams avoid carrying English title conventions into languages that capitalise differently, such as German, where all nouns take a capital, or French, where titles usually don’t.
Sentence case doesn’t mean lowercasing names, brands or abbreviations that properly take capitals. “Sign in with Google” keeps its capital G. Sentence case also makes proper nouns more obvious in titles: their capitals stand out against the surrounding lower-case words, rather than blending into the pattern of title case.
A style guide will usually explain how the rule applies to headings, buttons, job titles, product names and the first word after a colon, with examples from the organisation’s own content.
How AI changes the picture
AI can convert text between sentence case and title case and apply a documented convention across large content sets. It can also misread proper nouns, product names and deliberate capitalisation, so automated changes need review.
Clear machine-readable guidance helps. “Use sentence case for headings and buttons” works better with examples and an approved list of names. Without that context, models often reproduce the mixed conventions in their training material.
AI-generated interfaces can create headings on the fly. Documented rules and an approved name list improve the odds, but a rule in a prompt doesn’t guarantee correct capitalisation, so generated headings still need checking.
Questions people ask
- Is sentence case more accessible?
Sentence case is widely recommended as an accessible content practice, though it isn’t a WCAG requirement and the benefit may vary by reader and context. Clear wording, correct heading structure and enough visual distinction matter more. Choose a consistent convention and test the real interface.
- Should buttons use sentence case?
Usually, if that’s the product convention. Write buttons as clear actions and keep proper nouns capitalised.
- What about job titles?
Many British style guides use lower case for generic job titles and capitals only when the title begins a sentence or forms part of a formal name. Recording the organisation’s choice and sticking to it is good practice, though it’s an area where people tend to be especially attached to capital letters.
- Can we change an existing site automatically?
Tools can help, but review names, acronyms and text embedded in images. Capitalisation is easy to change mechanically and surprisingly easy to change wrongly.
Learn more
- Making a case for letter case – John Saito on Dropbox’s choice of sentence case, and how capitalisation affects readability, recognition of proper nouns and the way a brand feels.
- Making the case for sentence case – USAGov’s account of weighing readability, grammar and consistency before changing its sites.
- Capitalization – the Microsoft Style Guide’s rules for sentence-style capitalisation, including exceptions for product names and the first word after a colon.
- How letter casing affects comprehension of UI content – an interface-design perspective on casing and comprehension; useful reasoning to weigh against the actual context.