Case Converter

How it works

This tool converts text between casing styles directly inside your browser tab — no server, no upload, no waiting. Type or paste into the box and click a style: the text is transformed in place, and if you select a fragment first, only the selection is converted — handy for fixing one word or one heading inside a larger text. Every action can be undone. Whatever style you paste in, the text is first split into individual words using boundary detection that understands spaces, underscores, hyphens, and camelCase/PascalCase capitalization changes (including acronym runs like "XML" or "URL"), then rejoined in whichever style you pick.

Title Case follows the conventional "smart" rule used in book and article titles: short connector words stay lowercase in the middle of a title but are always capitalized at the start and end — and you can switch it to the exact rules of the AP, APA, Chicago, or MLA style guides. Sentence case capitalizes the first letter after every period, question mark, or exclamation point. The programming-identifier styles — camelCase, PascalCase, snake_case, kebab-case, CONSTANT_CASE, dot.case, path/case, and Header-Case — are the ones you'll recognize from variable, class, file, and HTTP-header naming conventions. Multi-line input is converted line by line, so a pasted list of headlines or identifiers converts in one go, with changed words highlighted in the result.

Unicode text styling: bold, italic, strikethrough, underline and more

Beyond case conversion, the Styling group generates decorated text you can paste anywhere plain text is allowed: 𝗯𝗼𝗹𝗱 and 𝘪𝘵𝘢𝘭𝘪𝘤 (mathematical sans-serif letters), s̶t̶r̶i̶k̶e̶t̶h̶r̶o̶u̶g̶h̶ and u̲n̲d̲e̲r̲l̲i̲n̲e̲ (combining marks added after every character), ˢᵘᵖᵉʳˢᶜʳⁱᵖᵗ and subscript, ꜱᴍᴀʟʟ ᴄᴀᴘꜱ, ｆｕｌｌｗｉｄｔｈ "wide" text, Ⓑⓤⓑⓑⓛⓔ letters, and upside-down text. None of it is formatting — every result is an ordinary Unicode string, which is exactly why it survives pasting into Instagram bios and captions, X/Twitter posts and names, Discord and WhatsApp messages, YouTube comments, or a plain-text email, where real bold/italic formatting is stripped.

Being upfront about the trade-offs: these are lookalike characters, not styled letters. Screen readers may announce them awkwardly (often letter-by-letter), search inside a page won't match them against regular words, and a handful of platforms with older fonts can render individual characters as boxes. Unicode also doesn't define a complete alphabet for every style — missing superscript/subscript letters are deliberately left unchanged rather than faked. For decorating a name, a bio line, or a short post they're perfect; for long body text, stick to real formatting.

Limitations

Word-boundary detection is a heuristic, not a dictionary lookup — an unusual mix of capitalization can occasionally split or join words differently than you'd expect, particularly with numbers embedded in identifiers. Casing operations always use fixed, locale-independent rules rather than your browser's language setting, specifically to avoid locale quirks like Turkish's dotted/dotless "I" silently changing results.

FAQ

Is this case converter really free?

Yes — completely free, with no size limits and no account required. Everything runs in your browser, so there's no server cost to recoup.

Does Title Case capitalize every word?

No — it uses the conventional "smart" title case rule: short connecting words like "a", "the", "of", and "and" stay lowercase unless they're the first or last word, matching how book and article titles are actually styled (e.g. "The Lord of the Rings", not "The Lord Of The Rings").

Can I convert FROM camelCase or snake_case, not just to it?

Yes — the input is analyzed for word boundaries regardless of its original style, so "myVariableName", "my_variable_name", and "My Variable Name" all convert identically to any target case, including correctly splitting acronym runs like "XMLHttpRequest" into "XML", "Http", "Request".

Why does uppercasing "i" sometimes behave unexpectedly in other tools?

Some case converters use locale-aware casing, which under a Turkish system locale turns "i" into "İ" (with a dot) instead of the expected plain "I" — a classic bug that can silently corrupt code identifiers. This tool always uses fixed, locale-independent casing so results are consistent everywhere.

What is the difference between the AP, APA, Chicago and MLA title case styles?

They disagree about which small words stay lowercase. AP and APA lowercase articles, conjunctions and prepositions of three letters or fewer, so longer prepositions like "With" and "Between" are capitalized. Chicago and MLA lowercase prepositions regardless of length ("through", "between"), and MLA additionally lowercases "so" and "yet". First and last words are always capitalized in every style.

Can I convert several headlines at once?

Yes — each line of the input is converted independently, so you can paste a whole list of titles (or identifiers) and convert them in one go.

How do bold, strikethrough and the other styled texts work — is it a font?

No font is involved. The styling buttons replace each letter with a Unicode character that already looks bold, struck through, circled, and so on (mathematical alphanumeric symbols and combining marks). Because the result is plain text, it survives copy-paste into places that strip formatting — Instagram bios, X/Twitter posts, Discord, WhatsApp, YouTube comments.

Will styled text work everywhere?

Almost everywhere modern fonts are used, but with two honest caveats: a few platforms or older fonts may show some characters as boxes, and screen readers often spell styled text letter-by-letter, so it's best for decoration rather than long passages.

Why are some superscript or subscript letters left unchanged?

Unicode simply does not define superscript/subscript forms for every letter (there is no superscript "q", and no subscript "b", "c" or "d", for example). Characters without a defined form are kept as-is instead of being replaced with a wrong lookalike.