Sentence Case Converter

Format text into proper Sentence case where only the first letter of each sentence is capitalized.

100% Client-Side

Input

Chars: 0Words: 0

What is Sentence Case Converter?

This sentence case converter fixes capitalization so that only the first letter of each sentence is capitalized, the way standard prose should read. It's perfect when you've got text typed entirely in lowercase, or messy mixed casing, and just want it to convert to sentence case cleanly and correctly.

How It Works

The tool identifies sentence boundaries by detecting ending punctuation like periods, question marks, and exclamation points, then capitalizes the first letter following each boundary while converting the rest of each sentence to lowercase, except for proper handling of standalone capital letters where relevant.

Is It Safe to Use?

Your text is processed locally in your browser with nothing transmitted elsewhere, so drafts or private messages you're formatting stay fully private.

How to Use Sentence Case Converter (Step-by-Step Guide)

Paste your text into the input box.
The tool automatically detects sentence boundaries.
View the properly capitalized sentence case output.
Copy the result to your clipboard.
Paste it into your document or message.

Frequently Asked Questions

How does it know where one sentence ends and another begins?

It looks for sentence-ending punctuation marks like periods, question marks, and exclamation points to determine where to capitalize the next letter.

Will it fix text that's currently in all lowercase?

Yes, that's one of its main uses — taking text typed entirely in lowercase and properly capitalizing the first letter of each sentence.

Does this capitalize first letter of sentence only, or every word?

Only the first letter of each sentence gets capitalized; for capitalizing every major word, you'd want the Title Case Converter instead.

Can I use this on mobile?

Yes, it works the same on mobile browsers as on desktop.

What happens to abbreviations like "Mr." or "U.S."?

Since those contain periods that aren't true sentence endings, there can occasionally be edge cases worth double-checking in longer documents.

Is there a character limit?

No, it works on text from a single sentence to a full multi-paragraph document.

Can this sentence case generator fix text pasted from an all-caps source?

Yes, it converts all-caps text down to proper sentence case just as easily as it handles all-lowercase input.

Is this tool free?

Yes, there's no cost to use it.

Style Guide Comparison

Style	Prepositions	Conj. lowercase	Last word
Chicago	≤ 4 letters	for, and, nor, but, or	✓
AP	≤ 3 letters	FANBOYS	✓
APA	≤ 3 letters	FANBOYS	–
MLA	All	FANBOYS	✓
AMA	≤ 3 letters	FANBOYS	–
NY Times	Selected	for, and, but, or	✓

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