Text typed quickly, transcribed from speech, or pasted from a source with inconsistent capitalization often has sentences that don't properly start with a capital letter — a small but noticeable proofreading issue.
This tool detects sentence boundaries (following periods, exclamation points, and question marks) and automatically capitalizes the first letter of each following sentence, correcting this common formatting inconsistency throughout your text.
This differs from full sentence-case conversion (which also lowercases everything else) — this tool only fixes the capitalization at sentence starts, leaving any other existing capitalization (like proper nouns) untouched.
Because everything runs locally in your browser, results appear instantly and nothing you type or upload is ever sent to a server.
Bookmark this page if you expect to use this tool regularly — it loads fast and behaves the same way every time, with no account needed.
This kind of task shows up constantly in everyday writing, coding, design, and admin work, which is exactly why a dedicated, focused tool saves so much back-and-forth.
A tool that does one job well, without a cluttered interface or unrelated features competing for attention, tends to be faster to use than a heavier all-in-one app.
If you find yourself needing this often, keeping this page open in a tab is usually faster than digging through a bigger software suite's menus.
Because there's no sign-up or installation step, you can jump straight from a search result to a working tool in a couple of seconds.
The interface is intentionally simple, so there's no learning curve — the input goes in, the result comes out, and that's the whole interaction.
Unlike a heavier desktop application, there's nothing to download, update, or configure before you can start using this tool.
Frequently asked questions
Does this lowercase the rest of each sentence too?
No, this only capitalizes the first letter after each sentence boundary — existing capitalization elsewhere in the text, like proper nouns, is left as you typed it.
How are sentence boundaries detected?
The tool looks for periods, exclamation points, and question marks followed by whitespace as sentence-ending punctuation, then capitalizes the next letter after each one.