Sentence Case Converter
Sentence case is the capitalization of ordinary prose: the first word of each sentence starts with a capital letter and the other words are lowercase. This sentence case converter finds sentence boundaries, skips decimals and abbreviations such as Dr., and keeps acronyms (NASA) and mixed-case words (iPhone) when the rest of the line is not in capitals.
Sentence Case Converter examples
| Case | Input | Output |
|---|---|---|
| Text typed in all caps | THE QUICK BROWN FOX. IT JUMPS. | The quick brown fox. It jumps. |
| Acronyms and apostrophes | the NASA launch is today. it's delayed? no! | The NASA launch is today. It's delayed? No! |
| Mixed-case words | i bought an iPhone on eBay. iPhone sales rose. | I bought an iPhone on eBay. iPhone sales rose. |
| Title case to sentence case | This Title Was Written In Title Case | This title was written in title case |
| Colon and hyphen | the follow-up: a review of the plan | The follow-up: a review of the plan |
| Decimals and abbreviations | meet at 3.30 p.m. today. bring the report. | Meet at 3.30 p.m. today. Bring the report. |
| Brackets | (see the report.) it is long. | (See the report.) It is long. |
Sentence Case Converter rules
- The first letter of each sentence is capitalized, and the other letters are lowercased.
- A sentence ends at a period, question mark, or exclamation point. Decimals (3.14) and known abbreviations (Dr., e.g., p.m.) do not end a sentence.
- On a line that also has lowercase letters, words written entirely in capitals (NASA, FBI) keep their capitals.
- On such a line, words with a capital after their first letter (iPhone, eBay, McDonald) keep their casing, even at the start of a sentence (iPhone sales rose).
- A line written entirely in capitals is lowercased first, then each sentence start is capitalized.
- Opening quotation marks and brackets are skipped, so the first letter inside them is capitalized.
- A line break without end punctuation continues the sentence; a blank line always ends it.
- Proper nouns and the pronoun "I" are not detected, so names such as smith and words such as i'm stay lowercase. Fix those by hand.
How sentence case differs from title case
Sentence case capitalizes only the first word of each sentence. Title case capitalizes every major word of a title and keeps only short articles, conjunctions, and prepositions lowercase, so "A review of the plan" in sentence case is "A Review of the Plan" in title case. Try the same text in the Title Case Converter.
Full comparison with examples: Title Case vs Sentence Case: Which Should You Use?
How to use
Type or paste your text into the editor.
Press Sentence case to convert the text in place. Pasted text converts at once.
Check names and the word "I", then copy the result.
When to use Sentence Case Converter
Writers and editors
Fixing paragraphs typed with Caps Lock on, or text pasted in title case.
Product and UX writers
Headings, buttons, and menu labels, when your style guide uses sentence-case headings.
Students and researchers
Article and book titles in an APA reference list, which APA 7 writes in sentence case.
Marketers
Email subject lines and social posts written in a conversational style.
FAQ
Sentence case capitalizes the first word of each sentence and proper nouns, and lowercases everything else, the way ordinary prose is written. This converter capitalizes sentence starts and keeps all-caps acronyms and mixed-case words such as iPhone; it cannot detect proper nouns.
Paste the text into the editor above. A line typed entirely in capitals is lowercased, then the first letter of each sentence is capitalized. Names need to be capitalized by hand.
Yes, when the line also has lowercase letters: words written entirely in capitals keep their capitals. On a line typed entirely in capitals, every word is lowercased first, acronyms included.
The converter does not know which words are names, so it lowercases every word except sentence starts, all-caps words, and words typed with a capital after the first letter (iPhone, McDonald). Capitalize other names and the pronoun "I" yourself.
The conversion runs in your browser, so your text is not uploaded to a server to be converted.