Transform case.

A meticulous case converter for writers, editors, and developers — with explain mode, eight style guides, and every programming convention you'll ever need.

prose code play
Input mode:
Input
Output
0 words 0 chars 0 sentences 0 min read
Why transformcase

Built for people who care what the words look like.

Most case converters are buttons over a textarea. This one knows the difference between an AP-style headline and an APA paper, capitalizes "iPhone" and "GraphQL" correctly, and shows you why every word was changed.

i.

Eight title-case styles, done correctly

AP, Chicago, APA, MLA, NY Times, Wikipedia, Bluebook, AMA — each with the right rules for articles, conjunctions, prepositions of every length, hyphenated compounds, and post-colon capitalization.

ii.

Explain mode

Hover any word in the output to see exactly why it was capitalized or lowercased. "Capitalized as major word." "AP rule: keep lowercase (article)." No more guessing.

iii.

A proper-noun dictionary that learns

5,000+ brands, places, programming languages, and scientific terms baked in. iPhone, GraphQL, NASA, PostgreSQL — all kept in their canonical form even mid-sentence.

iv.

Diff view + bulk + file upload

See exactly what changed with red strikethrough deletions and green insertions. Convert line-by-line in bulk mode. Upload .txt, .md, .csv, or .json files and download the result.

v.

Every programming case

camelCase, PascalCase, snake_case, kebab-case, CONSTANT_CASE, dot.case, path/case, URL slugs. Smart tokenizer handles ALLCAPS runs (HTMLParser → html_parser correctly).

vi.

Runs entirely in your browser

No upload, no server round-trip, no tracking of your text. The whole conversion engine is ~20 KB of JavaScript and runs at full keyboard speed.

Text tools

More than just case.

A growing toolkit for the small, finicky text problems you run into every day — find and replace with regex, clean whitespace, strip HTML, generate Markdown tables, sort lists, hunt down invisible characters, and reflow text pasted from PDFs. All free, all browser-based, no signup.

Style guides at a glance

Same sentence, eight rule sets.

A title-cased headline looks different in The New York Times than in an APA paper. Here's the same input under each style — try them yourself by switching pills above.

AP

Associated Press. Lowercase articles, coordinating conjunctions, and prepositions of three letters or fewer. The newsroom standard.

"the quick brown fox jumps over the lazy dog" The Quick Brown Fox Jumps Over the Lazy Dog
Chicago

Chicago Manual of Style. Lowercase articles, conjunctions, and prepositions regardless of length. The book-publishing default.

"the way through the woods" The Way through the Woods
APA

APA 7th edition. Capitalize words of four letters or more — even prepositions. Academic social-science papers.

"with great power comes responsibility" With Great Power Comes Responsibility
MLA

MLA Handbook. Lowercase all prepositions regardless of length; capitalize first and last word always. Humanities writing.

"the man with the golden gun" The Man with the Golden Gun
NY Times

New York Times manual. Similar to AP but with editorial nuance for headlines, captions, and standing heads.

"a study of pangrams in english" A Study of Pangrams in English
Wikipedia

Wikipedia manual of style. Lowercase articles, conjunctions, and prepositions up to four letters. For article titles and section headings.

"how to make a pot of tea" How to Make a Pot of Tea
Bluebook

Legal-citation standard. Lowercase articles, conjunctions, and prepositions of four or fewer letters. For case names and law reviews.

"a treatise on the law of contracts" A Treatise on the Law of Contracts
AMA

AMA Manual of Style. Lowercase articles, conjunctions, and prepositions of three or fewer letters. Medical and scientific publication.

"a randomized trial of new therapies" A Randomized Trial of New Therapies
For developers

Every naming convention you've ever needed.

A smart tokenizer that respects camelCase humps, ALLCAPS acronym runs, and Unicode letters — so HTMLParser becomes html_parser not h_t_m_l_parser.