Developer Utilities
Small developer utilities that save a trip to a random website. Encode and decode Base64, explain a regex, build UTM links, generate QR codes and vCards, and more — the everyday helpers. Free in your browser, and available by API when you need them in a script.
Developer Utilities
Unicode strikethrough text
cross out plain messages, free
POST /enc/strikethrough-unicode$0.002Developer Utilities
Unicode subscript text
letters & digits ↔ ₀₁₂ style for formulas, free
POST /enc/subscript-unicode$0.002Developer Utilities
Unicode superscript text
letters and digits to superscript
POST /enc/superscript-unicode$0.002Developer Utilities
Swedish spelling alphabet
spell or decode Adam Bertil Cesar, free
POST /enc/swedish-spelling$0.002Developer Utilities
System V sum checksum
sum -s style checksum and block count
POST /enc/sysv-sum$0.002Developer Utilities
T9 predictive text encoder
letters to keypad digits and back
POST /enc/t9$0.002Developer Utilities
Police ten-code translator
10-4 meanings and reverse lookup, free
POST /enc/ten-code$0.002Developer Utilities
Ubbi Dubbi translator
encode and decode Ubbi Dubbi free
POST /enc/ubbi-dubbi$0.002Developer Utilities
UIC wagon number check digit
compute and validate free
POST /enc/uic-wagon$0.002Developer Utilities
Unicode escape sequence converter
text ↔ \uXXXX, free
POST /enc/unicode-escape$0.002Developer Utilities
Unicode NFD normalizer
canonical decomposition, free
POST /enc/unicode-nfd$0.002Developer Utilities
Unicode NFKC normalizer
fold ligatures and compatibility forms, free
POST /enc/unicode-nfkc$0.002Developer Utilities
Unicode NFKD normalizer
compatibility decomposition, free
POST /enc/unicode-nfkd$0.002Developer Utilities
UPC-A check digit
compute from 11 digits or validate a 12-digit code
POST /enc/upc-check$0.002Developer Utilities
UPC-E converter
expand to UPC-A and compress back free
POST /enc/upce$0.002Developer Utilities
Upside down text flip
invert text with Unicode look-alikes
POST /enc/upside-down$0.002Developer Utilities
RFC 3986 percent encoder & decoder
unreserved set, free
POST /enc/url-rfc3986$0.002Developer Utilities
UTF-32 code unit encoder
text to 32-bit hex or decimal, free
POST /enc/utf32$0.002Developer Utilities
UTF-7 encoder and decoder
seven-bit-safe Unicode, free
POST /enc/utf7$0.002Developer Utilities
Modified UTF-7 IMAP encoder
encode or decode mailbox names, free
POST /enc/utf7-imap$0.002Developer Utilities
UK UTR check digit
compute and validate Unique Taxpayer Reference
POST /enc/utr-uk$0.002Developer Utilities
Uuencode encoder & decoder
classic Unix begin/mode rows, free
POST /enc/uuencode$0.002Developer Utilities
VIC cipher
straddling checkerboard encrypt/decrypt, free
POST /enc/vic-cipher$0.002Developer Utilities
Western Union phonetic alphabet
Adams Boston Chicago, free
POST /enc/western-union-phonetic$0.002Developer Utilities
XML entity encoder
escape & < > ' ", free
POST /enc/xml-entities$0.002Developer Utilities
xxencode encoder
encode or decode EBCDIC-safe text, free
POST /enc/xxencode$0.002Developer Utilities
yEnc encoder and decoder
Usenet binary encode/decode, free
POST /enc/yenc$0.002Developer Utilities
Zero-width character encoder
hide & reveal secret text, free
POST /enc/zero-width$0.002Developer Utilities
Angle between two lines calculator
acute angle from two slopes
POST /geom/angle-between-lines$0.002Developer Utilities
Annulus sector area calculator
two radii and angle, free
POST /geom/annulus-sector-area$0.002Developer Utilities
Annulus width from area calculator
outer radius and ring width
POST /geom/annulus-width-area$0.002Developer Utilities
N-antiprism calculator
volume and surface area from sides and edge
POST /geom/antiprism$0.002Developer Utilities
Astroid area and perimeter calculator
A = (3/8)πa², P = 6a
POST /geom/astroid$0.002Developer Utilities
N-gonal bipyramid calculator
volume and surface from n, edge, height
POST /geom/bipyramid$0.002Developer Utilities
Bretschneider formula calculator
area from sides and opposite angles
POST /geom/bretschneider-area$0.002Developer Utilities
Chebyshev distance calculator
chessboard L∞ distance between two points
POST /geom/chebyshev-distance$0.002Developer Utilities
Circle area from radius calculator
A = πr² free online
POST /geom/circle-area-radius$0.002Developer Utilities
Circle circumference calculator
C = 2πr from radius
POST /geom/circle-circumference$0.002Developer Utilities
Circle around a square calculator
enclosing radius from side
POST /geom/circle-circumscribed-square$0.002Developer Utilities
Circle diameter from circumference calculator
d = C/π free online
POST /geom/circle-diameter-circumference$0.002Developer Utilities
Circle from center and point
radius and standard equation
POST /geom/circle-from-center-point$0.002Developer Utilities
Circle radius from area calculator
r = √(A/π), free
POST /geom/circle-radius-area$0.002Developer Utilities
Triangle circumcircle area
circumscribed circle from 3 sides
POST /geom/circumcircle-area$0.002Developer Utilities
Collinear points checker
are three points on a straight line?
POST /geom/collinear-points$0.002Developer Utilities
Cone apex angle calculator
full apex angle from radius and height
POST /geom/cone-apex-angle$0.002Developer Utilities
Cone lateral surface area
A = π r l from radius and slant height
POST /geom/cone-lateral-area$0.002Developer Utilities
Cone slant height calculator
radius and height to generator length
POST /geom/cone-slant-height$0.002Developer Utilities
Conic eccentricity calculator
circle, ellipse, parabola, hyperbola
POST /geom/conic-eccentricity$0.002Developer Utilities
Coplanarity checker
test if four 3D points lie on one plane
POST /geom/coplanar-points$0.002Developer Utilities
Sphere circumscribed about a cube calculator
radius and volume from edge
POST /geom/cube-circumscribed-sphere$0.002Developer Utilities
Cube space diagonal calculator
diagonal from edge length a√3
POST /geom/cube-diagonal$0.002Developer Utilities
Cube surface area from volume calculator
S = 6·V^(2/3)
POST /geom/cube-surface-volume$0.002Developer Utilities
Cuboid space diagonal calculator
d = √(l²+w²+h²) free
POST /geom/cuboid-diagonal$0.002Developer Utilities
Cuboid surface area calculator
total surface from L×W×H free
POST /geom/cuboid-surface$0.002Developer Utilities
Brahmagupta formula calculator
cyclic quadrilateral area from four sides
POST /geom/cyclic-quadrilateral-area$0.002Developer Utilities
Ptolemy theorem calculator
cyclic quadrilateral diagonals
POST /geom/cyclic-quadrilateral-diagonals$0.002Developer Utilities
Cycloid arc length and area calculator
one arch from radius r
POST /geom/cycloid$0.002Developer Utilities
Cylinder height from volume calculator
height from volume and base radius
POST /geom/cylinder-height-volume$0.002Developer Utilities
Cylinder lateral surface area
A = 2π r h from radius and height
POST /geom/cylinder-lateral-area$0.002Developer Utilities
Decagon area calculator
regular 10-gon from side length, free
POST /geom/decagon-area$0.002