Sentence Case Converter

Convert text to Sentence Case — capitalise each sentence, lowercase the rest.

Processed locally – files never leave your device

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Converts live as you type. Nothing is uploaded — the conversion happens in your browser.

Sentence Case text

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Pasted text in ALL CAPS, or a paragraph typed with Caps Lock on? This free sentence case converter restores ordinary capitalisation: the first letter of every sentence becomes a capital and everything else becomes lowercase, except the pronoun “I”. It is the quickest fix for shouty copied text and messy form entries.

Everything runs in your browser, so your text is never uploaded or stored. For headings, use the Title Case Converter instead, and if you want every letter small first, start with the Lowercase Converter.

How to use

Paste or type your text into the input box above.
Watch the Sentence Case version appear live in the output box — no button needed.
Use Copy to copy the converted text, or Clear to start over with new text.

Why use Toolsvine

Fixing capitalisation should not mean pasting private text into a stranger's server, and with Toolsvine it does not. The conversion is done by JavaScript on your own device, so drafts, messages and client copy never leave your computer. It is free, has no limits, and works offline once the page has loaded.

The sentence-case rule, stated plainly

This tool applies one simple rule and states it honestly: the first letter of each sentence is capitalised, and every other letter is lowercased, except the standalone pronoun “I” (and its contractions such as “I'm” and “I'll”), which stays capital. A sentence is taken to end at a full stop, an exclamation mark or a question mark, so “hello world. how are you?” becomes “Hello world. How are you?”

Where sentence case is used

Sentence case is the default capitalisation for ordinary writing: body text, emails, messages, essays and most web content. It is also the house style for headings in many publications and for reference lists in APA style, where book and article titles are written in sentence case rather than title case. Headings in sentence case look calmer and more modern than title case, which is one reason many news sites and blogs now prefer it.

What it cannot know

Text	Result	Why
hello world. how are you?	Hello world. How are you?	First letters capitalised
i went to london	I went to london	“I” kept; “london” lowercased
meet dr. smith today	Meet dr. Smith today	“Dr.” ends a “sentence” here

Because the rule lowercases everything else, proper nouns such as London and names such as Smith lose their capitals — the tool cannot tell a name from an ordinary word. Abbreviations such as “Dr.” can also split a sentence, as the table shows. Always read the result once and restore capitals on names and places before you publish.

Frequently asked questions

Is my text uploaded anywhere?

No. The conversion runs entirely in your browser with JavaScript. Your text never leaves your device, and the tool keeps working if you go offline after the page loads.

What exactly is sentence case?

Sentence case means only the first letter of each sentence is capital, and the rest of the letters are lowercase — except the pronoun I. It is the capitalisation used for ordinary sentences, emails and body text.

Why did London become london?

This tool lowercases everything except sentence starts and the pronoun I, and it cannot recognise proper nouns. Names of people, places and brands need their capitals restored by hand after converting.

What counts as the end of a sentence?

A full stop, an exclamation mark or a question mark. The next letter after one of those marks is capitalised. Abbreviations such as Dr. can trick the tool into starting a new sentence, so check those spots.

When should I use sentence case instead of title case?

Use sentence case for body text, emails and most web headings. Use title case for book titles, formal headings and headlines where your style guide asks for it. APA reference lists use sentence case for titles.

Can it fix text typed in all caps?

Yes, that is its most common use. Paste the uppercase text here and it comes back in normal sentence capitalisation. Remember to restore capitals on names afterwards.