Markdown Preview / HTML ↔ Markdown

Case Converter

Convert text or an identifier into every common naming style at once — camelCase, snake_case, kebab-case, and more. Recognizes word boundaries in camelCase/PascalCase, acronyms (XMLParser → XML + Parser), and around digits.

Text Diff

Compare two texts line by line — what was added, removed, or changed, with word-level highlighting inside changed lines.

Regex Tester / Find & Replace

Test regular expressions against real text: highlighted matches with parsed capture groups, or replace matches with new text.

Sort & Dedupe Lines

Sort lines of text alphabetically, remove duplicates, empty lines, and extra whitespace.

String Escape

Escape text into a string literal (quotes, backslash, control characters) for pasting into code, or unescape it back.

CRLF ↔ LF Converter

Convert line endings between Windows (CRLF), Unix/macOS (LF), and classic Mac (CR), with mixed-ending detection.

Age Calculator

Exact age from a birth date — years/months/days, total time lived, and the next birthday.

TOTP Generator/Verifier

Time-based one-time passwords (TOTP, RFC 6238) — generate the current code from a secret and verify an entered code with clock-drift tolerance.

Query String ↔ JSON

Parse a URL query string into a JSON object, or build a query string back from JSON.

Argon2 Hash + Verify

Hash passwords with Argon2 (winner of the Password Hashing Competition, RFC 9106) — d/i/id variants, with verification against an existing hash.

Unicode Escape

Encode and decode Unicode escape sequences — characters as \uXXXX and back.

Cookie Parser

Parse a Set-Cookie header or a Cookie/document.cookie string into name, value, attributes, and a check for common security mistakes.