About the Case Converter
What you are reading describes a tool that is still being written. The converter will move text between UPPERCASE, lowercase, Sentence case and Title Case, and its title casing will follow an actual style guide rather than capitalizing every word it meets — the naive version turns the cat in the hat into The Cat In The Hat, which no guide accepts. Zyff will do the transformation server-side and keep no copy of what you paste.
How to change text case online
Paste your text
Drop in a headline, a column of names, a list of product titles or a whole paragraph. Line breaks are preserved, so a pasted list comes back to you as a list.
Pick the case style
Choose UPPERCASE, lowercase, Sentence case or Title Case. The planned set also covers the identifier styles developers need, such as camelCase, snake_case and kebab-case.
Choose a title case rule
Title case is not one rule. Pick AP or Chicago and the converter applies that guide's treatment of short words, rather than capitalizing everything and hoping for the best.
Review and copy
Scan the output for names, acronyms and brand spellings no rule set can know about, fix the handful that need a human, then copy the result in a single click.
What the Case Converter does
Style-aware title case
AP and Chicago disagree about short words, so you choose the guide instead of accepting one opinion baked into the tool. Same headline, correct output for either house style.
Sentence case that finds sentences
Real sentence case needs boundary detection, because splitting on every period breaks on e.g., Dr. and decimals. Capitalizing the first character of a blob is not the same job.
Acronyms kept intact
Planned protection for all-caps terms and mixed-case names, so NASA does not come back as Nasa and iPhone does not come back as IPhone after a title case pass.
Developer naming styles
Beyond prose casing, the converter will handle camelCase, PascalCase, snake_case, kebab-case and CONSTANT_CASE for variable names, URL slugs and CSS class names.
Cases your editor cannot do
Word's Shift+F3 cycles three options and Google Docs offers four; neither knows AP from Chicago, and neither will hand you snake_case or a URL slug. That gap is the reason this tool exists.
Frequently asked questions
What is title case?
Title case capitalizes the significant words in a heading and leaves the minor ones lowercase. Every major style guide capitalizes nouns, pronouns, verbs, adjectives and adverbs, plus the first and last word of the title. They disagree about which short words stay lowercase, which is why one headline can be correctly capitalized two different ways.
What is the difference between AP and Chicago title case?
The split is prepositions. AP capitalizes words of four letters or more, so Walking Through the Woods keeps Through capitalized. Chicago lowercases prepositions regardless of length, giving Walking through the Woods. Both lowercase articles (a, an, the) and coordinating conjunctions (and, but, or, nor, for) unless one opens or closes the title.
Why does my title case converter capitalize 'in' and 'the'?
Because it is capitalizing the first letter of every word rather than applying a style guide. That naive pass gives you The Cat In The Hat instead of The Cat in the Hat, and it flattens acronyms and brand spellings on the way through. Correct title case needs a lowercase word list plus first-and-last-word handling.
Is 'is' capitalized in a title?
Yes. Is is a verb, and every major style guide capitalizes verbs in a title no matter how short they are, so This Is the Way is correct. Only articles, coordinating conjunctions and, depending on the guide, prepositions get lowercased, and even those are capitalized as the first or last word.
What is sentence case?
Sentence case capitalizes the first word of a sentence and any proper nouns, and leaves the rest lowercase, exactly like ordinary prose. It is standard for interface labels, reference lists in APA style and many publications' headlines. Converting to it properly means finding sentence boundaries and keeping names intact, not lowercasing the whole string.
How do I change uppercase to lowercase without retyping?
Paste the text into a case converter and select lowercase. That is faster than retyping and avoids introducing new typos in text that was already correct. If you need readable prose afterwards, run sentence case rather than lowercase, so the first word of each sentence and any names stay capitalized.
Is Zyff's case converter available yet?
No. This page describes a tool that does not exist yet; the converter is still being written. When it does land there is no fee and no sign-in, and the only thing that happens to your text is the conversion you asked for.