Split YAML front-matter from a document — returns the parsed metadata object and the remaining content body. Malformed YAML is rejected as a clean 400.

Given an emoji character (or any string), return its code points and — if known — its name, category, shortcodes and tags. An unknown emoji is a successful result with `known:false`, not an error.

Decode HTML entities (named, decimal and hex numeric references) back into plain text.

Encode a word with the classic Soundex algorithm (letter + 3 digits) for phonetic matching of names.

Fletcher checksum over the input payload, in 16-bit (default) or 32-bit width. Returns the checksum as an unsigned integer and hex. Non-cryptographic.

Classify a User-Agent by device form factor and return convenience booleans (isBot, isMobile, isTablet, isDesktop, isTouchCapable) for routing decisions.

Encode a word with the Metaphone algorithm — more accurate than Soundex for English pronunciation.

Expand a fraction to its decimal form by exact long division, detecting a repeating cycle and rendering it in parenthesis notation (e.g. 1/6 → '0.1(6)', 1/7 → '0.(142857)'). maxDigits caps a non-repeating expansion. A zero denominator is a clean 400.

Return the plural form of an English word (handles irregulars — person → people, mouse → mice).

Flatten a nested object/array into a single-level object whose keys are the delimited paths to each leaf (default delimiter `.`). Requires an object or array.

Generate one or more UUIDs. Supports v4 (random), v1/v7 (time), and v3/v5 (namespaced).

Choose the singular or plural form for a given count, e.g. (apple, 3) → "apples", (apple, 1) → "apple". By default the count is prepended ("3 apples"); set includeCount=false to omit it.

Sanitize untrusted HTML to a safe allowlist. Keeps common formatting and links but removes dangerous scripting tags, inline event handlers and unsafe URL schemes. Ideal for rendering user-supplied HTML.

Validate a ULID and extract its embedded timestamp and time/random components.

Validate a UUID and report its version and variant.

Compute a cryptographic digest (SHA-2, SHA-3, BLAKE2, and legacy SHA-1/MD5/RIPEMD-160) of some data. The input may be utf8/hex/base64/base64url and the digest is returned as hex/base64/base64url.

Return the synonyms of an English word, aggregated across all its senses. Optionally filter by part of speech. An unknown word returns found:false with a 200.

Return the singular form of an English word (handles irregulars — people → person, mice → mouse).

CRC-32 (IEEE 802.3 polynomial, as used by zip, gzip and PNG) over the input payload. Returns the checksum as an unsigned integer and 8-digit hex. Non-cryptographic — for error detection only.

Estimate password strength: score, guesses, crack-time and feedback. Never stored.