Text Case Converter at a glance
- What it does
- Convert text between uppercase, lowercase, sentence case, title case, camelCase, snake_case, kebab-case and URL slugs instantly in your browser.
- Where it runs
- Entirely in your browser — no data is uploaded
- Works offline
- Yes, once the page has loaded
- Cost
- Free, with no account and no usage limit
- Category
- Text Utilities
How to use the case converter
- Paste your text - a word, a heading, or a long list with one item per line.
- Choose a case. Each button transforms the whole input at once.
- Copy the result, or convert again from the original if it was not what you wanted.
The cases, and where each belongs
| Case | Example | Used for |
|---|---|---|
| UPPERCASE | ANNUAL REPORT | Acronyms and constants. Avoid for body text - it is measurably slower to read and reads as shouting. |
| lowercase | annual report | Normalising input before comparison. Email addresses, tags, search keys. |
| Sentence case | Annual report | Headings and UI labels in most modern style guides, including Google's and Apple's. |
| Title Case | Annual Report | Book and article titles under AP and Chicago style. Still standard in journalism. |
| camelCase | annualReport | Variables and functions in JavaScript, Java, C# and Swift. |
| PascalCase | AnnualReport | Classes, types and React components. |
| snake_case | annual_report | Python variables, database columns, most SQL schemas. |
| kebab-case | annual-report | URLs, CSS class names, HTML attributes, file names. |
| Slug | annual-report-2026 | URL paths: lowercase, hyphenated, with punctuation and accents stripped. |
Title case is harder than it looks
Naive title case capitalises every word. Real title case does not: style guides keep articles, short prepositions and coordinating conjunctions lowercase unless they begin or end the title. "The Rise of the Machines" - not "The Rise Of The Machines".
The guides disagree on the details. Chicago lowercases prepositions of any length; AP capitalises those of four letters or more, so it writes "Between" but not "with". Neither handles hyphenated compounds or proper nouns automatically. Any automated conversion is a first pass, and a human should read the result.
This is one reason sentence case has won in software interfaces: it is unambiguous, it is faster to read, and it does not require a style ruling on every heading.
Making a good URL slug
A slug is the human-readable part of a URL. Good ones are lowercase, hyphen-separated, short and descriptive, and they never change once published.
- Hyphens, not underscores. Google has treated hyphens as word separators and underscores as joiners for years.
- Strip accents and punctuation.
café-münchenbecomescafe-munchen. Percent-encoded characters in a URL are ugly and break in older systems. - Drop filler words - "a", "the", "and" - unless removing them changes the meaning.
- Leave out dates and IDs unless you need them for uniqueness. A slug with a year in it looks stale the following January.
- Never change a published slug without a 301 redirect from the old one, or you lose every link and every ranking signal pointing at it.
Where case conversion goes wrong
Turkish. The lowercase of "I" in Turkish is "ı", not "i". Locale-insensitive lowercasing has broken real authentication systems, because a username normalised on a Turkish device stopped matching the stored value.
German ß. Uppercasing gives "SS", and lowercasing "SS" does not reliably return "ß". The round trip is lossy.
Acronyms in camelCase. parseHTTPResponse or parseHttpResponse? Most modern style guides prefer the second, treating an acronym as an ordinary word, because it makes automatic conversion between cases reversible.
Proper nouns. No converter knows that "iPhone", "eBay" and "McDonald" are not mistakes. Check names after converting.
Frequently asked questions
Because that is what title case means in every major style guide. Articles, coordinating conjunctions and short prepositions stay lowercase unless they are the first or last word.
Lowercase with hyphens. URLs are case-sensitive on most servers, so mixed case creates duplicate-content problems when someone links to a different capitalisation.
It uses the browser's Unicode-aware case functions, so accented Latin, Cyrillic and Greek convert correctly. Turkish dotted and dotless "i" is a known edge case that generic conversion cannot get right without locale information.
No. The conversion is pure string manipulation in your browser, so unpublished drafts and internal documents stay on your machine.
Nothing you enter here leaves your browser
Text Case Converter does its work in JavaScript running on your own device. The page loads once, and after that there is no upload step and no server involved — which matters here because unpublished drafts, contracts and internal documents stay on your machine.
You can verify this rather than taking our word for it: load the page, disconnect from the internet, and the tool keeps working. Our privacy policy sets out what is and is not collected, and this guide explains why the distinction matters.