Calculate subnet details (network, broadcast, usable hosts, mask) from a CIDR like 192.168.1.0/24

Check if an IPv4 address is private/reserved and identify which range it falls in

Pretty-print or minify a JSON string

Decode a JWT (header + payload + expiry check) without verifying the signature

Encode text as base64

Decode a base64 string to text

Compute a hash digest of text (md5, sha1, sha256, sha384, sha512)

Parse a 5-field cron expression and compute the next N run times

Generate one or more random UUID v4 values

Convert a Unix timestamp (seconds or ms) to ISO 8601, or get the current time if omitted

Parse a human/ISO date string into ISO 8601 and Unix timestamp forms

Convert a color between hex, rgb(), and hsl() formats

Line-by-line diff of two text blocks, returning added/removed/unchanged lines

Convert config data between JSON, YAML, and TOML

Evaluate an arbitrary-precision math expression exactly (fixes LLM multi-digit arithmetic errors). Supports +,-,*,/,^,sqrt(),sin(),log(), etc.

Count tokens in text using the GPT-3.5/4 (cl100k_base) tokenizer. Useful for managing context budget before sending a large prompt

Add or subtract days/weeks/months/years/businessDays from a date, handling leap years and month boundaries correctly

Compute the exact difference between two dates in days, business days, and hours

Convert a UTC/ISO date into a formatted date+time string for any IANA time zone

Compute mean, median, stdev, variance, min/max, and percentiles (25/75/90) for a list of numbers

Convert a value between units of length, weight, volume, or temperature (fixes LLM unit-math errors)

Compute exact great-circle distance in km/miles between two lat/long coordinates

Compute n! exactly using arbitrary-precision integer math (avoids float64 overflow past ~18)

Compute nPr (permutations) exactly using arbitrary-precision integer math

Compute nCr (combinations) exactly using arbitrary-precision integer math

Convert a number between decimal, hex, binary, and octal

Compute exact edit distance and similarity ratio between two strings (deterministic fuzzy matching)