What is a Case Converter?
A case converter is a free online text utility that rewrites the capitalization of letters in any string without altering the words themselves. Whether you need a screaming headline in UPPERCASE, a tidy kebab-case URL slug, a Python-friendly snake_case variable name, or a polished Title Case blog title, this tool handles all 13 common formats instantly — and your text never leaves the browser.
Pro tip: Bookmark this page — every conversion runs offline once cached, perfect for sensitive drafts and on-the-go editing.
How to Use the Case Converter
- 1
Paste or type your text
Drop any paragraph, headline, or single word into the input box at the top. Use the Paste button to pull from your clipboard.
- 2
Pick a case format
Choose UPPERCASE, lowercase, Title Case, camelCase, snake_case, kebab-case, or any of the 12 supported formats from the toggle group.
- 3
Tune slugify (optional)
If you picked Slug, choose your separator, lowercase, max length, and whether to strip accented characters.
- 4
Copy, download, or share
Use Copy to put the result on your clipboard, Download to save as .txt, or Share via the native Web Share sheet on mobile.
Supported Cases & Formats
Below is the full set of formats this converter supports, with an example transformation of "The Quick Brown Fox".
| Format | Example output |
|---|---|
UPPERCASE | THE QUICK BROWN FOX |
lowercase | the quick brown fox |
Title Case | The Quick Brown Fox |
Sentence case | The quick brown fox |
camelCase | theQuickBrownFox |
PascalCase | TheQuickBrownFox |
snake_case | the_quick_brown_fox |
kebab-case | the-quick-brown-fox |
CONSTANT_CASE | THE_QUICK_BROWN_FOX |
dot.case | the.quick.brown.fox |
aLtErNaTiNg | tHe qUiCk bRoWn fOx |
iNVERSE | tHE qUICK bROWN fOX |
Slugify (URL) | the-quick-brown-fox |
What is Slugify? URL-Friendly Strings Explained
A slug is the human-readable, lowercase portion of a URL that identifies a page: in /blog/case-converter-online, the slug is case-converter-online. Search engines treat clean slugs as a ranking signal — they're crawlable, shareable, and convey topic instantly. Slugify applies four rules:
Normalize Unicode
Accented characters like é, ñ, ü are decomposed to ASCII (e, n, u) for full browser & CDN compatibility.
Replace non-alphanumerics
Spaces, punctuation, and symbols collapse into a single hyphen (or underscore). Consecutive separators squash so you never get --.
Lowercase everything
URLs are case-insensitive in spec but case-sensitive in practice across many servers. Lowercasing avoids duplicate-content issues.
Trim length
Google typically displays only the first ~75 characters. Slugs under 60 characters look cleanest in search results.
Common Use Cases
Writers & editors
Convert headlines to Title Case or Sentence case to match your house style guide.
Developers
Turn descriptions into camelCase, PascalCase, snake_case, or CONSTANT_CASE.
SEO specialists
Generate clean URL slugs for blog posts, landing pages, and product pages.
Data analysts
Normalize messy spreadsheet headers into a single consistent case.
Social media managers
Emphasize posts with UPPERCASE or playful aLtErNaTiNg case without manual typing.
Students
Reformat copy-pasted research into Sentence case for essays.
Title Case vs Sentence Case
Title Case
The Quick Brown Fox Jumps
Capitalizes every major word. Default for blog headlines, book titles, and YouTube videos in AP & Chicago style guides.
Sentence case
The quick brown fox jumps
Capitalizes only the first word (and proper nouns). The modern, calmer choice — used by Apple, the BBC, and most product UIs.
Rule of thumb: pick one and stick with it across your site for a cohesive brand voice.
Privacy & Performance
Every conversion runs locally in your browser using plain JavaScript — no server round-trip, no logging, no analytics on your text content. The tool ships as a single lightweight bundle with zero third-party scripts in the calculator itself, so it loads fast even on slow connections and works offline once the page is cached.