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Sentence Case Converter
Convert any text to sentence case — capitals only where a sentence starts, with acronyms kept.
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Sentence Case Converter works on your text locally in your browser.
Turn shouting or title-style text into normal sentences
Text often arrives with the wrong capitals: an email typed with caps lock on, a spreadsheet export in all capitals, or headings written in Title Case that need to become ordinary sentences. This converter capitalizes the first word of each sentence and the word “I”, lowercases everything else, and keeps acronyms such as NASA — so the result reads like normal writing.
How to convert text to sentence case
- Type or paste your text, or choose Upload Document to open a .txt, .md, .docx, or .pdf file.
- The result appears immediately below.
- Choose Copy Result to use it elsewhere, or Replace Input with Result to keep working here — Undo Replace brings the original back.
How sentences are detected
- A sentence starts at the beginning of the text, at every new line, and after . ! ? or … followed by a space.
- Common abbreviations such as Dr., Mr., e.g., and i.e., and single initials like “J.”, do not start a new sentence.
- The pronoun “I” and its contractions (I’m, I’ve, I’ll) are always capitalized.
- Acronyms and words with inner capitals (NASA, iPhone) are kept; a sentence typed entirely in capitals is converted like ordinary words.
| You enter | You get |
|---|---|
| THE MEETING IS AT NOON. PLEASE BE ON TIME! | The meeting is at noon. Please be on time! |
| dr. smith said we should use NASA data. i agree. | Dr. smith said we should use NASA data. I agree. |
| this Is A Title-Style Line | This is a title-style line |
These are the same rules the Looty Tools Sentence Counter uses, so the two tools always agree on where sentences begin.
Your text stays on your device
- Text is processed by JavaScript running in your browser.
- Your text is never uploaded to Looty Tools or any other server.
- Uploaded documents are opened and read in your browser; the file itself is never sent to Looty Tools.
- Nothing is stored — refreshing or closing the page clears both boxes.
Limitations
- Uploads accept .txt and .md files up to 5 MB, Word .docx files up to 15 MB, and PDFs up to 25 MB and 50 pages. Older .doc files are not supported, and scanned or image-only PDFs have no text to use.
- Names, places, and brands written in normal case cannot be recognized, so “Paris” becomes “paris” — review proper nouns after converting.
- Abbreviations outside the built-in list (such as “etc.”) followed by more text are treated as the end of a sentence.
- Acronyms inside a sentence typed entirely in capitals are lowercased along with the rest of that sentence.
Related text tools
- Sentence CounterCount the sentences in a piece of writing.
- Case ConverterSwitch text between upper, lower, title, and sentence case.
- Title Case ConverterCapitalize the main words in a title.
Guides
- Capitalization After Colons and QuotesWhen to capitalize the first word after a colon, inside quotation marks, and in parentheses — including how APA and Chicago’s 17th and 18th editions differ.
- Proper vs. Common NounsThe difference between proper and common nouns, and how to capitalize job titles, seasons, directions, family words, and brand names.
- Fixing Text Typed in All CapsWhere all-caps text comes from, which capitalization to convert it to, what a converter cannot recover, and a safe workflow for restoring names and acronyms.
Sentence Case Converter FAQ
- What does sentence case do to my text?
- It capitalizes the first word of every sentence and the pronoun “I”, and makes every other letter lowercase — except acronyms and brand names with inner capitals, such as NASA or iPhone, which are kept.
- Why did a name become lowercase?
- Sentence case works by rules, not a dictionary of names, so it cannot tell that “paris” or “smith” should be capitalized. Check names, places, and brands after converting and fix them by hand.
- How does it know where a sentence starts?
- It uses the same rules as the Looty Tools Sentence Counter: a sentence ends at . ! ? or … followed by a space or line break, common abbreviations like “Dr.” and “e.g.” do not end a sentence, and every new line starts a sentence.
- Is this the same as the Case Converter’s Sentence case option?
- Yes. It runs exactly the same conversion — this page simply does that one job without choosing a style.
- Does it work on text typed in all caps?
- Yes. A sentence written entirely in capitals is treated as ordinary words, so “MEETING MOVED TO FRIDAY.” becomes “Meeting moved to friday.” — remember to re-capitalize names like Friday.
- Can I upload a Word document or PDF instead of pasting?
- Yes. Upload Document accepts .txt, .md, Word .docx, and text-based .pdf files, or you can drop a file onto the text box. The file is read in your browser — it is not sent to Looty Tools — and its text replaces whatever is in the box. Scanned PDFs without a text layer and older .doc files are not supported.
- Is my text uploaded?
- No. The conversion runs in your browser, and your text is never sent to Looty Tools or saved. Refreshing the page clears it.
