AI Case Converter
Ten cases, built around the two jobs AI drafts actually create: fixing headlines that arrive over-capitalised, and turning a title into a URL slug. It reads existing identifiers in any convention, so converting a database column into a component name is one step too.
Assistants capitalise headlines like a press release from 1994.
Ask an assistant for a headline and it will hand you “How To Improve Your Email Open Rates In Five Steps”. Every word capitalised, including to, your and in. It is not title case, it is not sentence case, and it is not what any publication uses.
The habit comes from the training data. Headlines appear on the web in every capitalisation convention there is, and capitalising everything is the safest average of them. It reads as slightly wrong to anyone who works with copy, in the same way an em dash every other sentence does, and for the same reason: it is a pattern that does not match how people actually write.
There are two jobs here and they are both tedious by hand. Fixing the capitalisation to something a style guide would accept, and turning that headline into a URL slug without introducing a different inconsistency. Both are one step above.
A note on the slug in particular: a headline generated by an assistant frequently carries characters the writer never typed. Those survive into a slug and produce a URL that looks right and resolves to nothing, which is worth clearing before converting rather than after.
Title case is not capitalising every word.
“The Quick Brown Fox Jumps Over the Lazy Dog” is title case. “The Quick Brown Fox Jumps Over The Lazy Dog” is not. The difference is the second the, and every major style guide — Chicago, AP, MLA — agrees that it stays lowercase.
The rule is that articles, coordinating conjunctions and short prepositions stay lowercase unless they are the first or last word of the title. Everything else is capitalised. It is a small rule, and it is the difference between a headline that reads as edited and one that reads as processed.
What this converter applies is the shared core of those guides, which is what matters for the AI-headline case: the output stops announcing itself. It is worth saying plainly that the guides differ in the details — APA capitalises prepositions of four letters or more, Chicago does not — so if you are writing to one specific guide, a dedicated title-case tool that lets you pick between them will serve you better than this will. For turning an assistant’s over-capitalised headline into something publishable, one sound rule is enough.
Ten conventions, and what each is for.
- Sentence case
The quick brown fox jumpsCapitalises the first letter of each sentence and lowercases the rest. This is the fix for text that arrived in capitals, and it is the default here because it is what most prose actually wants. - lowercase
the quick brown fox jumpsEverything down. Used for normalising data before comparison, for email addresses, and for anything that will be matched against something else, since case differences are the most common reason two identical-looking values fail to match. - UPPERCASE
THE QUICK BROWN FOX JUMPSEverything up. Legitimate for short labels and headings, and genuinely harder to read in quantity, because capitals remove the ascenders and descenders that let you recognise word shapes without reading them. - Title Case
The Quick Brown Fox Jumps Over the Lazy DogCapitalises the significant words and leaves the minor ones lowercase: articles, short conjunctions and short prepositions. Note where the second the sits in that example. Almost every converter capitalises it, and every major style guide says not to unless it opens or closes the title. - aLtErNaTiNg
tHe qUiCk bRoWn fOxAlternates case letter by letter. It exists for one purpose, which is sarcasm on the internet, and it is here because people ask for it. - camelCase
theQuickBrownFoxFirst word lowercase, every subsequent word capitalised, no separators. The convention for variables and functions in JavaScript, Java and Swift. - PascalCase
TheQuickBrownFoxLike camelCase but with the first word capitalised too. Used for class and type names in most languages, and for component names in React. - snake_case
the_quick_brown_foxLowercase words joined with underscores. The convention in Python and Ruby, and the usual choice for database column names because it survives case-insensitive systems intact. - CONSTANT_CASE
THE_QUICK_BROWN_FOXUppercase words joined with underscores. Used for constants and, almost universally, for environment variables. - kebab-case
the-quick-brown-foxLowercase words joined with hyphens. The right form for URL slugs, CSS class names and HTML attributes. Note that it is not valid in most languages as an identifier, because the hyphen reads as subtraction.
Five reasons this comes up.
- Text that arrived in capitalsA form field with caps lock on, a legacy system that stores everything uppercase, a headline pasted from a design. Sentence case restores it in one pass, which is considerably faster than retyping and considerably more accurate than fixing it by eye.
- Headlines and headingsPublications specify title case and mean the style-guide version, not capitalising every word. Getting it wrong is a small thing that reads as carelessness to anyone who works with copy, which is exactly the audience a headline is for.
- Renaming things in codeConverting a name between conventions is a routine and tedious job: a database column in snake_case becomes a property in camelCase becomes a component in PascalCase. The converter handles all three, and reads an existing identifier in any convention as its input.
- URL slugs and CSS nameskebab-case is the correct form for both, and doing it by hand invites inconsistency across a site. Converting a title directly to a slug is one step, though you may want to shorten the result afterwards.
- Normalising dataLowercasing a column before comparison is how you stop the same value appearing three times because three people typed it differently. It is worth doing before deduplicating anything.
Case conversion questions.
Why does AI capitalise every word in a headline?
Because headlines appear on the web in every capitalisation convention there is, and capitalising everything is the safest average across them. The result is a headline that reads as slightly off to anyone who works with copy, in the same way that a heavy em dash habit does.
How do I fix an AI-generated headline?
Paste it and choose title case, which keeps articles, short conjunctions and short prepositions lowercase unless they open or close the title. That is the shared core of Chicago, AP and MLA, and it is what turns an over-capitalised headline into a publishable one.
How do I turn a headline into a URL slug?
Choose kebab-case. The words are lowercased and joined with hyphens, which is the correct form for a slug. Clean the headline of hidden characters first if it came from an assistant, since those survive into the slug and produce a URL that looks right and resolves to nothing.
Which style guide does the title case follow?
The shared core of Chicago, AP and MLA: minor words stay lowercase unless first or last. The guides differ in the details, most notably on how long a preposition has to be before it is capitalised, so if you are writing to one specific guide a dedicated title-case tool with selectable styles will suit you better.
How do I change text from uppercase to lowercase?
Paste it and choose lowercase, or sentence case if you want it to read as prose rather than as a run of lowercase words. Sentence case is the usual answer for text that arrived in capitals by accident, since it restores the capital at the start of each sentence too.
What is title case?
A convention where the significant words in a title are capitalised and the minor ones are not: articles, short conjunctions and short prepositions stay lowercase unless they are the first or last word. "The Quick Brown Fox Jumps Over the Lazy Dog" is title case. Capitalising every word is not.
Why do some tools capitalise every word in title case?
Because it is simpler to implement and looks approximately right. It is not what any major style guide asks for, and it is noticeable to anyone who works with copy. This converter keeps minor words lowercase by default, and the behaviour can be turned off if your house style differs.
What is the difference between camelCase and PascalCase?
Only the first letter. camelCase starts lowercase and PascalCase starts uppercase; both capitalise every subsequent word and use no separators. Convention is camelCase for variables and functions, PascalCase for classes, types and React components.
What is snake_case used for?
Python and Ruby identifiers, and database column names almost everywhere. The underscore survives case-insensitive systems and case-folding intact, which is why databases prefer it to camelCase.
What is kebab-case used for?
URL slugs, CSS class names and HTML attributes. It is not usable as an identifier in most programming languages, because a hyphen is parsed as the subtraction operator.
Can I convert an existing identifier to a different convention?
Yes. The converter reads camelCase, PascalCase, snake_case, CONSTANT_CASE and kebab-case as input and splits them into their component words, so converting between any two conventions works in one step.
Does converting to camelCase remove my line breaks?
The programming cases build a single identifier, so they collapse everything including line breaks by definition. Leave line by line on if you have a list of names to convert, and each line becomes its own identifier.
Will it handle accented characters?
Yes. Accented letters, Cyrillic and Greek all convert correctly, since case mapping is defined for them in Unicode. Note that the programming cases leave accented characters as they are, which is legal in most modern languages but not in all of them.
How do I change case in Microsoft Word?
Shift+F3 cycles a selection through lowercase, uppercase and capitalise-each-word. The Change Case button on the Home tab offers the same options plus sentence case. Note that Word's capitalise-each-word is not title case, for the reason above.
How do I change case in Excel?
The UPPER, LOWER and PROPER functions, applied in a helper column and then pasted back as values. PROPER capitalises every word, so it has the same limitation as Word's option and is not title case.
Is my text uploaded anywhere?
No. Everything runs in your browser. Nothing is transmitted or stored, and closing the tab discards it.