Capital letters sound like a small thing until you’ve typed a whole paragraph with caps lock on, or been handed a spreadsheet of names in ALL CAPS. The case converter fixes that in a click. Paste your text and every common style appears at once, so you can pick the one you want and copy it.
The styles, explained
UPPERCASE turns every letter into a capital. Useful for acronyms, warnings and some forms.
lowercase does the opposite. It’s the first step when you want to clean up text before applying another style, and it’s how many email addresses and usernames are normalised.
Title Case capitalises the main words of a heading and leaves small connecting words in lowercase, except at the start and end. “the quick brown fox jumps over the lazy dog” becomes “The Quick Brown Fox Jumps Over the Lazy Dog”. Styles differ on which words count as small, so treat the result as a very good starting point and adjust if your style guide is strict. We cover the differences in title case vs sentence case.
Sentence case capitalises the first letter of each sentence and leaves everything else lowercase. It’s the natural style for body text, and many modern interfaces and news sites use it for headlines too. Note that it doesn’t know which words are proper nouns, so names like London or Maria will be lowercased. Check those after converting.
camelCase joins words with no spaces and capitalises each word after the first: myVariableName. It’s common in JavaScript, Java and many other programming languages.
PascalCase is the same, but with the first letter capitalised too: MyVariableName. It’s widely used for class and component names.
snake_case puts underscores between lowercase words: my_variable_name. It’s popular in Python, Ruby and database column names.
kebab-case uses hyphens: my-variable-name. You’ll see it in URLs, CSS class names and file names. If you need a clean web address from a title, the slug generator goes a step further and strips punctuation and accents.
CONSTANT_CASE is upper-case snake case: MY_VARIABLE_NAME. It’s the convention for constants in many languages and for environment variables.
aLtErNaTiNg cAsE and iNVERSE cASE are mostly for fun, or for memes and playful posts. Inverse swaps the case of every letter, which also rescues text that was typed with caps lock on by mistake.
Converting lists of names
The programming styles are calculated one line at a time. Paste a column of names, one per line, and each is converted separately. The converter also understands existing camel humps, so userAccountId is split into user, account and id before being rejoined in the new style. That makes it handy for renaming columns and variables in bulk.
Practical tips
- If text is shouting at you because it’s all in capitals, convert to lowercase first and then to sentence case.
- For headlines, convert to title case, then read it once. Check acronyms like NASA or USB, which should stay capitalised, and check small words after a colon, which many guides capitalise.
- When you copy a list from a spreadsheet, remove accidental repeats first with remove duplicate lines.
- Need to change one word throughout? Find and replace is quicker than retyping.
- To check the length of a headline before you publish, paste it into the word counter.
Limits and edge cases
Automatic case conversion is quick but not mind-reading. It can’t know that “iPhone” should keep its odd capitalisation, or that “McDonald” has a capital in the middle. Sentence case will lowercase proper nouns, and title case may capitalise a word your style guide would leave small. Always scan the result before it goes into something important.
Different languages follow different rules for capitalisation, and a few letters change length when their case changes. Turkish has dotted and dotless i. German has the ß. The converter follows standard Unicode behaviour, which is right for most text.
One style at a time
This page shows every style together so you can compare them. If you only need one and want the result to be tidy, there are dedicated pages for uppercase, lowercase, title case, sentence case, camelCase, snake_case, kebab-case, PascalCase, CONSTANT_CASE and alternating case. Each one explains where its style is used and where the conversion can go wrong, for example with acronyms and apostrophes.