Free Text Case Converter
Convert text to any case format instantly — UPPER, lower, Title, camelCase, and more.
What is a text case converter?
A text case converter is a free online tool that instantly transforms text between different capitalization formats — UPPERCASE, lowercase, Title Case, camelCase, snake_case, kebab-case, and more. You paste your text, click a format button, and the converted output is ready to copy.
Ever get text pasted in ALL CAPS and need to fix it? Or need to turn a blog post title into a URL slug, or a variable name from snake_case to camelCase? I use this constantly when copying content between Notion and my code editor — the ALL CAPS problem alone saves me a minute per document.
How text case conversion works
Each case format has a specific rule. UPPERCASE replaces every letter with its capital equivalent using Unicode character mappings — this handles international characters like ä → Ä correctly. lowercase does the reverse. Title Case splits on word boundaries and capitalizes the first letter of major words while leaving articles (the, a, an) and short prepositions lowercase, following the APA style guide.
camelCase and PascalCase split text at spaces and punctuation, strip separators, and join words together with capital letters marking word boundaries. snake_case replaces spaces with underscores and lowercases everything. kebab-case does the same with hyphens. The 'Stripped' mode applies Unicode normalization to remove diacritics, converting é → e and ü → u — useful for generating ASCII-safe file names or URL slugs.
Common mistakes and limitations
The most common mistake is using the wrong case for the context. snake_case is the convention for Python variables and database columns; camelCase is standard in JavaScript; PascalCase is used for class names in most object-oriented languages. Using Title Case for blog post URLs is also wrong — URLs should use kebab-case. Another limitation: the tool cannot reliably handle acronyms like 'HTML' or 'NASA' in camelCase — it will produce 'html' instead of 'HTML' unless you handle them manually.
Title Case also has an edge case problem with hyphenated words: 'state-of-the-art' should become 'State-of-the-Art' in formal Title Case, but many converters get this wrong. Our tool capitalizes the first word of hyphenated compounds and leaves the rest lowercase — the most widely accepted convention for most style guides.
When to use a text case converter
I reach for a text case converter in four everyday situations. Writing blog posts and articles — I write in sentence case but need to convert headings to Title Case consistently. The difference between 'The Quick Brown Fox' and 'The quick brown fox' matters for readability, and doing it manually guarantees errors. Second, programming — I frequently copy variable names between the codebase and documentation, going from snake_case (Python conventions) to camelCase (JavaScript conventions) or Title Case for UI labels. Third, cleaning up imported data — CSV exports often arrive in inconsistent cases, and a quick uppercase or lowercase conversion normalizes everything. Fourth, creating URL slugs — converting 'My Amazing Blog Post Title' to 'my-amazing-blog-post-title' via lowercase then kebab-case saves manual hyphen-typing. The stripped mode is especially useful when dealing with multilingual content where accented characters need to become ASCII-safe for database keys or file names.
How to use this calculator
- Paste or type your text — Enter any text in the input box.
- Click a case button — Click any of the case buttons to instantly convert the text.
- Copy the result — Click the Copy button below the output to copy the converted text.
Frequently asked questions
How do I convert text to all uppercase or lowercase online?
Paste your text into the box above and click UPPERCASE to make every character capital, or lowercase to make every character small. The conversion happens instantly — no submit button needed.
What is the difference between Title Case and Sentence case?
Title Case capitalizes the first letter of every major word: 'The Quick Brown Fox Jumps.' Sentence case only capitalizes the first letter of the sentence: 'The quick brown fox jumps.' Title Case is used for headings; Sentence case is used for body text and blog posts.
What is the difference between camelCase, PascalCase, and snake_case?
camelCase starts lowercase and capitalizes each word: myVariableName. PascalCase capitalizes every word including the first: MyClassName. snake_case uses underscores: my_variable_name. kebab-case uses hyphens: my-url-slug. The right choice depends on your programming language's conventions.
Does the converter keep punctuation and special characters?
Yes — punctuation, numbers, and symbols are preserved in all case modes except snake_case and kebab-case, which replace spaces and some punctuation with underscores or hyphens respectively. The 'Stripped' mode removes diacritics (accents) to make text ASCII-safe for URLs.
Why does Title Case not capitalize words like 'the', 'and', and 'of'?
Proper Title Case follows the APA and Chicago Manual of Style rules: articles (a, an, the), short prepositions (of, in, on), and conjunctions (and, but, or) are not capitalized unless they are the first or last word of the title. Our tool follows this convention — some simpler tools capitalize every word, which is technically wrong for formal titles.
Can I convert text from snake_case back to readable English?
Yes — paste snake_case or kebab-case text and click 'Title Case' or 'Sentence case.' The tool splits on underscores and hyphens and capitalizes accordingly, making it useful for converting programming variable names back to human-readable labels.