other

Reformat a MAC address into the requested notation (colon, hyphen, Cisco dot or bare) and case (lower default or upper).

Bitwise AND across two or more non-negative integers (given as decimal strings, evaluated as arbitrary-precision BigInt). Returns the result in decimal, hex and binary.

Remove all HTML tags, returning the plain text content. Entities are decoded to real characters by default (set decodeEntities=false to keep them encoded).

Summarise a text's difficulty as a single consensus US grade level (averaging the five grade formulas), plus the Flesch Reading Ease, a plain-language difficulty band and an approximate age range.

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.

Test whether an IP address falls within a CIDR block. A well-formed address of a different family (or simply outside the block) returns contains=false — not an error.

Expand an RRULE recurrence rule into its occurrence datetimes, with a human-readable description.

Return the validation regular expression (source and flags) used for a country's postal codes.

Compute the WCAG 2.1 contrast ratio between two colors and whether it passes AA/AAA.

Reverse lookup: resolve a Unicode character name (e.g. 'SNOWMAN', 'CJK UNIFIED IDEOGRAPH-4E2D', 'HANGUL SYLLABLE GA') to its code point. Loose whitespace/case matching. An unknown name is a successful `found:false`.

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.

Format a numeric amount as currency for a given locale using Intl, honouring the currency's own minor-unit convention (USD→2, JPY→0). display selects the symbol, narrow symbol, ISO code or full name. An unknown currency or locale is a clean 400.

Split an amount into parts using integer minor-unit math so the shares always sum back to the exact original — no rounding drift. Pass parts for an even split, or ratios for a weighted one (e.g. [1,1,1] splits $100 into 33.34/33.33/33.33). The leftover minor units go to the largest fractional remainders.

Fuzzy-search emoji by name, shortcode or keyword tag, ranked exact → prefix → substring.

Extract the heading outline from Markdown — depth, text and a unique GitHub-style anchor slug for each heading. Optionally limit to a maximum heading depth.

Bitwise OR across two or more non-negative integers (given as decimal strings, evaluated as arbitrary-precision BigInt). Returns the result in decimal, hex and binary.

Look up the definitions of an English word. Returns one entry per sense with its part of speech, definition, example sentences and synonyms. Optionally filter by part of speech. An unknown word returns found:false with a 200.

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.

Report the properties of a MAC address encoded in its first octet: unicast vs multicast (I/G bit), universal vs locally-administered (U/L bit), the broadcast address, and — for EUI-48 — the OUI and NIC portions.

Build a scale from a root note and type (major, natural-minor, harmonic-minor, melodic-minor, dorian, phrygian, lydian, mixolydian, locrian, major-pentatonic, minor-pentatonic, blues, chromatic). Heptatonic scales and modes are spelled diatonically (F major → F G A Bb C D E). Returns the note names, MIDI numbers and semitone intervals.

Mask a card number for display, keeping the first six and last four digits (the PCI-permitted maximum) and replacing the rest with a mask character (default `*`).

Build the flag emoji for an ISO 3166-1 alpha-2 country code from its regional-indicator symbols (e.g. "US" → 🇺🇸). Non two-letter codes are clean 400s.

Normalise a postal code's casing and whitespace (uppercase, collapse runs of spaces) and report whether the normalised form is valid for the country.

Decode a base64, base64url, hex, base32, or URL percent-encoded string back into UTF-8 text. Malformed input for the chosen encoding is rejected as a clean 400.