📝 Sentence Case Converter

Convert text to Sentence case — capitalising only the first letter of each sentence and the rest in lowercase. Useful for cleaning up ALL-CAPS text or restoring natural reading flow.

What is the sentence case converter?

Sentence case is the natural default for English prose: first letter of each sentence is capital, the rest is lowercase except for proper nouns and special cases. It's how most readers expect prose to be formatted. Recovering it from all-caps or random-cap input is a common cleanup task.

How does this sentence case converter work?

Paste your text and click Convert. The tool lowercases everything, then re-capitalises the first letter at the start of the input and after every period, exclamation mark, or question mark followed by space.

When should you use this tool?

Use it to clean up emails or chat messages received in ALL CAPS, to fix legacy database content, to format documentation extracted from screenshots, and to prepare text for body-content publishing where natural capitalisation matters.

Tips & best practices

After conversion, manually re-capitalise proper nouns (people, places, products) and acronyms — the tool can't detect those. For bulk content with many proper nouns, a manual review is essential.

Frequently asked questions

Will it lowercase 'I' (the pronoun)?

Yes — and you'll need to re-capitalise it manually. Sentence case algorithms can't reliably distinguish 'i' from other lowercase letters.

What about acronyms like NASA?

They get lowercased and need manual restoration. For acronym-heavy text consider a different normalisation approach.

How does it detect sentence boundaries?

By the period+space pattern. Abbreviations like 'Mr.' or 'e.g.' may trip it up — review the output.

Related tools

Explore more case & format on the tool hub — or jump straight to the UPPERCASE Converter, lowercase Converter, Title Case Converter.