100% Free
In-browser
Real-time
Capitalize Sentences Free Online
Automatically capitalize the first letter of every sentence, fix lowercase "i", and correct contractions — live as you type. No upload, no signup.
Rules applied automatically
First character — the very first letter of the text is always capitalized.
After sentence-ending punctuation — the first letter following
. ! or ? (when followed by a space) is capitalized.Standalone "i" — the word i is capitalized wherever it stands alone as a pronoun, including contractions like i'm, i've, i'll, i'd, i'd, i'd.
How to use
Auto-capitalize in 2 steps
1
Paste or type your text
Drop your lowercase or mixed-case text into the editor. Sentence capitalization is applied the moment you stop typing each character.
2
Copy or download
Click "Copy Output" to grab the corrected text to your clipboard, or "Download .txt" to save it as a plain-text file.
3
Keep editing freely
Your cursor position is preserved on every keystroke — you can type, delete, and edit anywhere in the text without losing your place.