Case Converter
Change text to Sentence case, lowercase, UPPERCASE or Capitalized Case, or fix text typed with caps lock on.
Runs in your browser. Nothing you enter is uploaded.
How to use Case Converter
- Paste or type your text into the box.
- Pick a case: Sentence case, lowercase, UPPERCASE, Capitalized Case, alternating or swapped.
- Leave "Keep acronyms" on so words like USB and iPhone stay correct. It is ignored when the whole text is in capitals.
- Copy the converted text, or download it as a .txt file.
Examples
Text typed with caps lock on
- Convert to: Sentence case
PLEASE CHECK THE ATTACHED FILE AND LET ME KNOW WHAT YOU THINK. THANKS AGAIN!
Please check the attached file and let me know what you think. Thanks again!
The whole text is in capitals, so it is treated as caps lock text and every word is converted.
Mixed text with acronyms
- Convert to: Sentence case
my PC won't detect the USB drive. what should i do?
My PC won't detect the USB drive. What should I do?
PC and USB stay in capitals, "i" becomes "I", and each sentence starts with a capital.
A heading with every word capitalized
- Convert to: Capitalized Case
how to restart your router the right way
How To Restart Your Router The Right Way
Every word gets a capital, including short words like "to" and "the".
How it works
The text changes as you type or pick a case. Nothing is uploaded: the conversion runs in your browser.
| Case | Example | Use it for |
|---|---|---|
| Sentence case | My router keeps dropping. Can you help? | Fixing caps lock text, emails, normal writing |
| lowercase | my router keeps dropping. can you help? | Usernames, tags, email addresses |
| UPPERCASE | MY ROUTER KEEPS DROPPING. CAN YOU HELP? | Labels, warnings, short headings |
| Capitalized Case | My Router Keeps Dropping. Can You Help? | Names of things, simple headings |
| aLtErNaTiNg | mY rOuTeR kEePs DrOpPiNg | Jokes and memes |
| sWAP cASE | mY rOUTER kEEPS dROPPING | Undoing text typed with caps lock and Shift |
What Sentence case does with your text
- Sentences start after a full stop, question mark, exclamation mark or ellipsis followed by a space. Abbreviations like “e.g.”, “i.e.” and “Dr.” don’t end a sentence, and neither do decimals (3.5) or web addresses.
- Lines keep their breaks. A new line only gets a capital after a blank line, after a list marker (-, *, •, 1.) or when “Capitalize every line” is on. That way text with line breaks in the middle of a sentence stays correct.
- “i” on its own becomes “I”, including “I’m”, “I’ve”, “I’ll” and “I’d”.
- Acronyms and brand names stay as they are: all-caps words of two to five letters (USB, NASA, HDMI) and words with a capital inside (iPhone, YouTube, macOS). Longer all-caps words like IMPORTANT are treated as shouting and converted.
- Caps lock text: when most of the text is in capitals, every word looks like an acronym, so all of it is converted.
What it can’t know
Names of people, places and brands that are written in all capitals or all lowercase, like “LONDON” or “smith”, come out as ordinary words in Sentence case. Fix those by hand after converting. For headlines that follow AP, APA or Chicago style, where words like “to”, “and” and “the” stay lowercase, Capitalized Case isn’t the right choice.
Other languages
Accented letters (é, ü, ç), Cyrillic and Greek convert correctly, and German ß becomes SS in UPPERCASE. The conversion follows standard Unicode rules for every language, so Turkish dotted and dotless i follow the general rule rather than Turkish spelling.
Questions
How do I change uppercase to lowercase?
Paste the text above and choose lowercase, or Sentence case if you want capitals at the start of each sentence. In Microsoft Word, select the text and press Shift+F3 to cycle through the cases.
How do I fix text I typed with caps lock on?
Paste it here with Sentence case selected. Every sentence gets a capital first letter and the rest becomes lowercase. If you typed with caps lock on while holding Shift, it looks like "hELLO". Choose sWAP cASE to flip it back.
What is sentence case?
Sentence case capitalizes only the first word of each sentence, plus words that are always capitalized. It is how normal sentences are written: "My router keeps dropping the connection."
What is the difference between Capitalized Case and title case?
Capitalized Case capitalizes every word, including short ones like "to", "and" and "the". Title case follows a style guide such as AP or Chicago and keeps most short words lowercase.
How do I change all caps to lowercase in Excel?
Use =LOWER(A1) for lowercase, =UPPER(A1) for capitals or =PROPER(A1) to capitalize each word, then copy the results and paste them as values. Excel has no sentence case function, so paste the text here for that.
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Updated October 8, 2026 · Works in current Chrome, Edge, Firefox and Safari · Runs entirely in your browser