Sentence Case Converter Online — Free Tool

Paste it into the input box and press the convert button. The tool lower-cases everything, then raises the first letter of each sentence back to upper case. You only have to fix proper nouns and acronyms by hand afterwards.

A period, a question mark or an exclamation mark followed by a space. Colons, semicolons and bare line breaks are not treated as breaks, so the next letter stays lower case. Add the missing punctuation before converting if your text relies on line breaks alone.

No. The conversion is purely mechanical and has no dictionary, so NASA becomes nasa and London becomes london unless the word opens a sentence. Restore those by hand — there are usually only a handful and they stand out in the output box.

Yes. Case mapping is done by the browser using Unicode rules, so Cyrillic, Greek and accented Latin letters convert correctly. Scripts without letter case, such as Chinese or Arabic, are simply passed through unchanged.

There is no hard limit; the tab's memory is the only constraint. Tens of thousands of characters convert instantly. A very large document may freeze the tab briefly, so split it into chunks and run them one after another.

Nowhere. The page makes no network request with your content — the rewrite runs in a script on the page itself, and the result stays in the output box until you close the tab, which discards it.

Yes. Long-press to paste into the top box, tap the convert button, then the copy button. The result lands on the iOS or Android clipboard and can be pasted into any app. Note that the interface labels themselves are in Russian.