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.
Override how a specific word is capitalized — useful for brand names, usernames, or terms our dictionary doesn't recognize. Saved in this browser only; nothing is sent anywhere.
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.
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.
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.
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.
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.
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).
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.
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.
Find and Replace
Multi-pattern, regex, whole-word matching. Replace one string or a hundred in a single pass.
HTML Tag Stripper
Remove tags from HTML and keep clean text. Preserve line breaks or allowlist specific tags.
Whitespace Cleaner
Collapse multiple spaces, trim lines, remove blank lines, normalize line endings.
Markdown Table Generator
Paste CSV or TSV, get an aligned Markdown table ready for GitHub, Reddit, or any editor.
List Clean & Sort
Dedupe, sort A–Z or numerically, reverse, shuffle, strip prefixes. Lists made tidy.
Invisible Characters
Find zero-width spaces, BOMs, smart quotes, and other hidden Unicode in your text.
PDF Paste Cleanup
Joins broken lines, de-hyphenates, removes page numbers and repeating headers.
All text tools
Browse the full toolkit. More tools added regularly.
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.
Associated Press. Lowercase articles, coordinating conjunctions, and prepositions of three letters or fewer. The newsroom standard.
Chicago Manual of Style. Lowercase articles, conjunctions, and prepositions regardless of length. The book-publishing default.
APA 7th edition. Capitalize words of four letters or more — even prepositions. Academic social-science papers.
MLA Handbook. Lowercase all prepositions regardless of length; capitalize first and last word always. Humanities writing.
New York Times manual. Similar to AP but with editorial nuance for headlines, captions, and standing heads.
Wikipedia manual of style, for titles of works cited in articles. (Wikipedia's own article titles use plain sentence case, not this.)
Legal-citation standard. Lowercase articles, conjunctions, and prepositions of four or fewer letters. For case names and law reviews.
AMA Manual of Style. Lowercase articles, conjunctions, and prepositions of three or fewer letters. Medical and scientific publication.
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.
Lowercase first word, capitalize the rest. JavaScript variables, JSON keys, most modern language conventions.
PascalCaseCapitalize every word, no separators. Classes in most languages, .NET conventions, React components.
snake_caseLowercase with underscores. Python, Ruby, Rust functions and variables; SQL columns; YAML keys.
kebab-caseLowercase with hyphens. CSS class names, HTML attributes, CLI flags, URL paths.
CONSTANT_CASEUppercase with underscores. Constants in most languages, environment variables, configuration keys.
dot.caseLowercase with periods. i18n keys, configuration namespaces, file extensions in dotted form.
Frequently asked questions.
What is an online case converter tool?
A tool that changes the capitalization of text — upper, lower, sentence, title, or a programming case like camelCase — without you retyping it by hand. This one runs entirely in your browser, supports 8 title-case style guides and 6 programming cases, and never sends your text anywhere.
How do I change uppercase text to lowercase automatically?
Paste the text into the box above, select "lower" from the mode tabs, and the output updates instantly. Works on a single word, a sentence, or a full document.
Why did my text copy entirely in capital letters, and how do I fix it?
This usually happens when Caps Lock was on while typing, or text was copied from a source that used all-caps styling (some PDFs and legacy documents do this at the formatting level, not the text level). Paste it into the lowercase converter to normalize it, then re-capitalize properly with sentence case or title case as needed.
What is an inverse case converter, and what is random case used for?
Inverse case flips every letter's case — uppercase becomes lowercase and vice versa. Random case assigns each letter a random case. Both are mostly used for stylistic text (informal social posts, "mocking" text memes) rather than professional writing.
Can I convert multiple lines of text at once?
Yes — bulk/line-by-line mode is built in, and you can upload a .txt, .md, .csv, or .json file directly rather than pasting. See the bulk & files page for details.
Is this converter safe to use with sensitive or confidential text?
Yes — everything runs client-side in your browser using JavaScript. Your text is never uploaded to a server, logged, or stored anywhere outside your own browser's local storage (used only for your style preference and any custom terms you add).
What is explain mode, and how do I check why a word was capitalized?
Hovering any converted word shows a tooltip explaining exactly why it was capitalized that way — a dictionary match, a custom override, or a style-guide rule.
What is diff view, and how do I see exactly what changed in my text?
Diff view shows your original and converted text side by side with the specific changes highlighted, so you can verify exactly what the converter altered rather than re-reading the whole passage. Toggle it next to explain mode.
Why do text converters mess up brand names like iPhone or NASA?
Most naive converters lowercase or re-capitalize every word mechanically, which breaks names that don't follow normal capitalization rules. This tool ships with a 5,000+ term proper-noun dictionary specifically to keep brand names, tech terms, and acronyms correct through any conversion.
How do I add custom words to the converter so my brand name capitalizes correctly?
Click "Custom terms" near the output panel, add the word and its correct capitalization (e.g. "acmewidgets" → "AcmeWidgets"), and it takes precedence over the built-in dictionary from then on — saved in your browser, no account needed.
Where is my custom word list saved, and is it sent to a server?
It's saved only in your browser's local storage. It's never transmitted anywhere — not to this site's servers, not to any third party. Clearing your browser's site data for transformcase.com will also clear your custom terms.
Can I use this converter completely offline?
Once the page has loaded, the conversion logic runs entirely in your browser and doesn't need an internet connection to keep working — though you'd need connectivity to load the page itself the first time, or to reload it later.