Sentence case is the natural way we write prose: lowercase throughout, with only the first word of each sentence capitalised. This converter is most useful for fixing text that arrived in ALL CAPS or random mixed case, turning it back into readable sentences.
How it works
The converter first lowercases the entire input, then walks through it and capitalises the first letter that follows a sentence boundary:
- the start of the text
- a sentence-ending mark (
.,!, or?) followed by space - the start of a new line
After that, the standalone pronoun I and its contractions (I'm, I'll,
I've, I'd) are restored to uppercase so the result reads correctly.
Example and notes
THIS IS A SHOUTING SENTENCE. and here is another one! becomes
This is a shouting sentence. And here is another one!. Because the tool has no
dictionary of names, proper nouns such as cities, people, and brands are
lowercased and will need a manual fix — sentence case handles structure, not
semantics.
When sentence case is the right choice
Different parts of a document call for different capitalisation styles. Sentence case is standard for:
- Body text and paragraphs — normal prose is sentence case by definition.
- UI labels and form field labels — Apple’s Human Interface Guidelines and Google’s Material Design both recommend sentence case for most interface labels (only major navigation items and dialog titles use title case).
- Email body text — fixing a message drafted in all-caps or erratic mixed case before sending.
- Database content exports — legacy systems sometimes store string fields in ALL CAPS; sentence case is a reasonable default cleanup before displaying the content on a website.
- Social media captions and ad copy — shouted all-caps copy pasted from a brief reads more naturally in sentence case.
Title case, by contrast, is more appropriate for headings, book titles, article headlines, and navigation items.
Common scenarios where this tool saves time
Copy-pasted from a PDF — PDF text extraction often mangles case, particularly in documents that used decorative fonts or section headings set in small-caps. Paste the extracted text here to normalise the capitalisation.
ALL-CAPS legacy text — Older databases, some government forms, and 1990s-era software stored everything in uppercase for compatibility reasons. This converter turns a block of all-caps text into a readable starting point, which is usually faster than re-typing.
Mixed-case accidents — Auto-correct and phone keyboards sometimes capitalise mid-sentence after abbreviations (e.g. after “Dr.” or “St.”). If your text has random capitals in unexpected places, lowercasing everything and then applying sentence case removes the noise.
What the tool cannot do automatically
- Proper nouns — names of people, cities, companies, products, and brands will be lowercased. After converting, scan for any names and capitalise them manually.
- Abbreviations — short abbreviations like “UK”, “NASA”, or “HTML” will be lowercased and need to be fixed by hand.
- Mid-sentence I — the tool restores the standalone I and its common contractions (I’m, I’ll, I’ve, I’d), but possessives like “mine” or “myself” are not affected because they are not subject pronouns.
- Ellipses — a sentence ending with
...is not always a full stop; the converter treats the final.as a sentence boundary, which may not match your intent in all cases.