Tools
Every tool is defined by a spec (inputs, outputs, assumptions) and ships with golden test vectors.
All tools
Average power calculator
Compute average power from energy and time (P = E / t), with unit conversion.
Base64 encode/decode
Encode text as Base64 (or Base64URL) and decode Base64 back to UTF‑8 text.
BMI calculator
Calculate body mass index (BMI) from weight and height, including standard BMI categories.
Board feet calculator
Compute lumber volume from thickness × width × length, and view results in board feet.
Case converter
Convert text between camelCase, PascalCase, snake_case, kebab-case, and Title Case.
Circle area calculator
Compute the area of a circle from its radius, with unit conversion.
Circle circumference calculator
Compute the circumference of a circle (C = 2·π·r), with unit conversion.
Compound interest calculator
Compute compound interest final amount (A = P·(1 + r/n)^(n·t)).
Concrete volume calculator
Estimate concrete volume from slab length, width, and depth, with unit conversion.
Cone volume calculator
Compute the volume of a cone from radius and height (V = 1/3·πr²h), with unit conversion.
CRC32 checksum
Compute CRC32 (IEEE) checksum of text (UTF‑8 bytes) in hex and decimal.
Cylinder surface area calculator
Compute total surface area of a cylinder (A = 2·π·r·(r + h)), with unit conversion.
Cylinder volume calculator
Compute the volume of a cylinder from radius and height (V = πr²h), with unit conversion.
FNV‑1a hash (32‑bit)
Compute a fast, non-cryptographic 32-bit hash (FNV‑1a) in hex and decimal.
IPv4 subnet calculator
Compute network/broadcast addresses, netmask, and host range from an IPv4 address and CIDR prefix.
JSON checker
Validate JSON and show the top-level type (object, array, string, number, boolean, or null).
JSON formatter
Pretty-print and minify JSON. Optionally sort keys for stable, comparable output.
JWT decoder
Decode a JWT’s header and payload JSON (no signature verification).
Kinetic energy calculator
Compute kinetic energy from mass and velocity (E = 1/2·mv²), with unit conversion.
Loan payment calculator
Compute monthly payment, total payment, and total interest for a fixed-rate amortizing loan.
Password generator
Generate random (or seeded, deterministic) passwords with configurable character sets.
Percent change calculator
Compute absolute and percent change between an old value and a new value.
Pythagorean theorem calculator
Compute the hypotenuse length from two perpendicular sides using √(a² + b²).
Rectangle area calculator
Compute the area of a rectangle from length and width, with unit conversion.
Rectangle perimeter calculator
Compute the perimeter of a rectangle (P = 2·(L + W)), with unit conversion.
Regex escape
Escape special characters so text can be used safely inside a regular expression.
Simple interest calculator
Compute simple interest and final amount (A = P·(1 + r·t)).
Slugify text
Convert text into a URL-friendly slug (kebab-case or snake_case).
Sphere surface area calculator
Compute the surface area of a sphere (A = 4·π·r²), with unit conversion.
Sphere volume calculator
Compute the volume of a sphere from its radius (V = 4/3·πr³), with unit conversion.
Text comparer
Compare two texts and get a line-based diff plus an overall similarity score.
Trapezoid area calculator
Compute the area of a trapezoid from both bases and height, with unit conversion.
Triangle area calculator
Compute the area of a triangle from base and height, with unit conversion.
Unix timestamp converter
Convert between Unix epoch timestamps and ISO 8601 date/time (UTC).
URL encode/decode
Encode text for use in URLs (percent-encoding) and decode percent-encoded strings back to text.
URL parser
Parse a URL and extract components like protocol, host, path, query parameters, and fragment.
UUID / GUID generator
Generate UUIDv4 identifiers (aka GUIDs). Optionally use a seed for deterministic, reproducible output.