Text case converter (lower / upper / title / sentence)
Convert any text to lowercase, UPPERCASE, Title Case, or Sentence case instantly in your browser. No upload, no signup.
When to use which case
Use Sentence case for emails and Slack. Title Case for article headings. UPPER CASE only for acronyms.
All processing happens locally in your browser — your text never leaves this page.
Six conversion modes explained
- lower case — every letter becomes lowercase. Useful for email addresses, usernames, and code.
- UPPER CASE — every letter becomes uppercase, handy for headings and signs.
- Title Case — capitalises the first letter of each word, the standard style for article titles.
- Sentence case — capitalises only the first letter of each sentence, the natural style for body text.
- dedupe — removes duplicate lines and keeps the first occurrence. Great for cleaning copied lists.
- reverse — flips the character order. Useful for quick tests, or just for fun.
Common use cases
Cleaning up text copied from PDFs (which often arrives in SHOUTING CAPS), normalising product titles for a shop catalogue, fixing ALL-CAPS emails from a colleague who discovered the caps-lock key, removing duplicate rows from a pasted list, and preparing consistent labels for spreadsheets. Because the tool runs locally, it is also safe for text you would rather not paste into random websites.
How it works
Paste or type your text, pick a mode, and press run. The conversion happens instantly in your browser using plain JavaScript — nothing is uploaded, logged, or stored anywhere.
FAQ
Is there a length limit?
No hard limit. The tool comfortably handles book-chapter-sized text; your browser's memory is the only real ceiling.
Does it preserve line breaks?
Yes. Case modes change letters only; dedupe works line by line and keeps the original line order.
Can I convert non-English text?
Yes. Unicode is handled correctly, including accented letters and CJK text (though CJK has no case, so case modes leave it unchanged).
People also use this for…
Every tool below is also 100%% local: no upload, no account, no server copy — the same privacy guarantee you get on this page.
- Count the result
Word, character and reading time for the converted text. - Export the converted text to PDF
One click from text to a clean page. - Format JSON keys consistently
Keep camelCase or snake_case tidy across a payload.
How to convert text case
- Paste or type your text into the box.
- Choose the target style — lower case, UPPER CASE, Title Case or Sentence case.
- Click Run and copy the result. The original stays in the input box, so you can try another style without retyping.
- For headings and titles, Title Case is usually right; for body text that lost its formatting, Sentence case is the safer choice.
What each style does
- lower case — every letter becomes lowercase. Useful for normalising URLs, email addresses, CSS class names or tags.
- UPPER CASE — every letter becomes uppercase. Common for acronyms, legal emphasis, signage and constants in code.
- Title Case — the first letter of each significant word is capitalised. Headlines, book titles, product names.
- Sentence case — the first letter of each sentence is capitalised and the rest lowered. This is what body copy should look like, and it is the best fix for text that was pasted out of an all-caps source.
How it works, and where it has to guess
Case mapping uses the browser's Unicode-aware conversion, so accented characters and non-Latin scripts behave correctly — important for languages with special rules (Turkish dotless ı and dotted İ, for example). Two places involve judgement rather than rules. Title Case has to decide which words are "significant": most styles leave articles and short prepositions (a, an, the, of, in, to, and) lowercase, but there is no universal standard, so check the result against the style guide you are following. Sentence case has to decide where sentences end, which is done by looking for terminal punctuation followed by a space — so "e.g." and other abbreviations can cause a capital letter where you did not want one.
Privacy
The conversion is a string operation in your browser. No text is uploaded, no request is made and nothing is saved, which makes this safe for drafts, embargoed copy and internal documents.
Troubleshooting
- Acronyms became "Nasa" instead of "NASA": Title Case cannot know an all-caps word is an acronym. Fix that one word by hand after converting.
- Capital letter after "e.g." or "Dr.": the abbreviation's period looks like a sentence end. Correct it manually.
- German ß became "SS": that is the correct uppercase mapping for the character; use "ß" in lowercase contexts if your style requires it.
- Hyphenated words look wrong: styles differ on whether the second half is capitalised ("State-Of-The-Art" vs "State-of-the-Art"). Pick one and be consistent.
- Numbers or symbols changed unexpectedly: they should not — case conversion only affects letters.
FAQ
Can it handle text in other languages?
Yes for Unicode-aware case mapping, including accented Latin, Greek and Cyrillic. Scripts without case (Chinese, Japanese, Arabic) pass through unchanged, which is the correct behaviour.
Is there a size limit?
No practical one — tens of thousands of characters convert instantly.
Can it convert camelCase or snake_case?
Not directly. Paste into lower case first, then reformat; a dedicated identifier tool would handle those conventions better.