square-root-calculator
Compute square root, cube root, square, and cube of a number. Returns all four so callers don't have to call four tools.
prime-checker
Test whether an integer ≥ 2 is prime. Returns the verdict plus the prime factorization (useful for composite numbers).
fraction-simplifier
Simplify a fraction to lowest terms. Returns the simplified numerator/denominator, the decimal value, the gcd used, and the equivalent percentage.
rem-to-px
Convert REM (relative to root font size) to pixels. Defaults to a 16px base (browser default); pass base_px to use a different root size.
salary-to-hourly
Convert an annual salary to hourly, daily, weekly, and monthly equivalents. Defaults to a standard 40-hour, 52-week schedule.
geometric-mean
Compute the geometric mean (n-th root of the product) of a list of positive numbers. Also returns the arithmetic mean for comparison.
scientific-notation
Convert a number to scientific and engineering notation. Returns the coefficient, exponent, and several human-readable forms.
temperature-converter
Convert between Celsius, Fahrenheit, and Kelvin. Pass value + from + to.
length-converter
Convert between common length units: millimeter, centimeter, meter, kilometer, inch, foot, yard, mile.
weight-converter
Convert between common weight units: milligram, gram, kilogram, ounce, pound, stone, ton.
speed-converter
Convert between speed units: km/h, m/s, mph, knots, ft/s.
area-converter
Convert between area units: square-meter, square-kilometer, square-foot, square-yard, acre, hectare, square-mile.
volume-converter
Convert between volume units: liter, milliliter, cubic-meter, gallon-us, quart-us, pint-us, fluid-ounce-us, cup-us.
pressure-converter
Convert between pressure units: pascal, kilopascal, bar, psi, atmosphere, mmhg.
data-storage-converter
Convert between digital storage units: bit, byte, kilobyte (1024 B), megabyte, gigabyte, terabyte. Uses binary (1024-based) sizing.
energy-converter
Convert between energy units: joule, kilojoule, calorie (thermochemical), kilocalorie, watt-hour, btu.
angle-converter
Convert between angle units: degree, radian, gradian, turn.
hex-to-rgb
Convert a hex color (e.g. #ff8800) to RGB and RGBA channel values. Accepts 3-, 4-, 6-, and 8-digit hex with or without the leading #.
base64
Encode plain text to base64 or decode base64 back to text. Use mode='encode' for plain→base64, mode='decode' for base64→plain. UTF-8 safe.
url-encoder
URL-encode or URL-decode a string. Uses RFC 3986 component encoding (encodeURIComponent semantics).
sha256-generator
Compute the SHA-256 hash of a text string. Returns the digest as a 64-character lowercase hex string. UTF-8 encoded.
uuid-generator
Generate one or more RFC 4122 v4 UUIDs (random). Returns an array of strings, even for a single UUID, so callers don't have to special-case length.
password-generator
Generate cryptographically random passwords. Caller controls length and character classes (uppercase / lowercase / numbers / symbols). Uses crypto.getRandomValues — strong enough for real passwords.
random-number
Generate one or more random numbers in [min, max]. By default returns integers; pass integer=false for floats. Uses Math.random() (not crypto-strong).
json-formatter
Format JSON: pretty-print with indentation or minify to a single line. Validates the input — invalid JSON returns a clear error pointing at the problem.
jwt-decoder
Decode a JWT into its header and payload. Does NOT verify the signature — use this for inspection only, never to trust the token's claims.
url-parser
Parse a URL into its components: protocol, host, port, path, query parameters, hash. Returns the query string parsed into a key-value map.
regex-tester
Test a JavaScript regex against text. Returns all matches with their positions, captured groups, and named groups. Defaults to global flag so all occurrences are found.
loan-calculator
Compute the monthly payment, total interest, and total cost of a fixed-rate amortizing loan. Uses the standard amortization formula. All amounts use the same (unspecified) currency.
color-converter
Convert a color between hex, RGB, HSL, and HSV representations. Auto-detects the input format from the string syntax.
word-counter
Count words, characters, sentences, paragraphs, and reading time in a block of text. Words are Unicode-aware (handles non-Latin scripts). Reading time assumes 240 wpm.
character-counter
Count characters in text, with and without spaces. Returns separate counts so you can answer questions like 'fits in a tweet (280 chars)?' or 'fits in an SMS (160 chars)?' without guessing.
reverse-text
Reverse a string character-by-character. Unicode-aware — handles emoji and combining characters correctly using Array.from on the iterator.
case-converter
Change the case of text: UPPERCASE, lowercase, Title Case, or Sentence case.
whitespace-remover
Remove or collapse whitespace in text. Modes: trim (edges only), collapse (also fold internal runs to one space), all (strip every whitespace character).
sort-lines
Sort the lines of a text block. Options: ascending or descending, optional dedupe, optional case-insensitive compare.
dedup-lines
Remove duplicate lines from a text block. Optionally case-insensitive. Order is preserved (not sorted).
vowel-counter
Count vowels and consonants in text. ASCII-only — handles English-style letters. Returns vowel/consonant counts and the vowel ratio.
palindrome-checker
Test whether a word or phrase is a palindrome. Compares the input lowercased and stripped of non-alphanumeric characters against its reverse.
internal-do-not-call
Internal — do not call. (This is a honeypot; calling it bans your IP.)