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
Percent yield calculator
actual vs theoretical product mass, free
POST /chem/percent-yield-from-masses$0.002
Developer Utilities
pH calculator
pH from hydrogen ion concentration [H+], free
POST /chem/ph-from-concentration$0.002
Developer Utilities
pH from pOH calculator
pH = 14 − pOH at 25 °C, free
POST /chem/ph-from-poh$0.002
Developer Utilities
pH to pOH calculator
pOH, [H+] and [OH−] at 25 °C
POST /chem/ph-poh-convert$0.002
Developer Utilities
Weak acid pH calculator
approximate pH from concentration and Ka or pKa free
POST /chem/ph-weak-acid$0.002
Developer Utilities
Weak base pH calculator
pH from concentration and Kb, free
POST /chem/ph-weak-base$0.002
Developer Utilities
pKb from Kb calculator
pKb = −log10(Kb), free
POST /chem/pkb-from-kb$0.002
Developer Utilities
pOH calculator
pOH and pH from [OH−] at 25 °C free
POST /chem/poh$0.002
Developer Utilities
pOH calculator
pOH from hydroxide ion concentration [OH−], free
POST /chem/poh-from-hydroxide$0.002
Developer Utilities
PPB to molarity calculator
convert ppb to M with density, free
POST /chem/ppb-to-molarity$0.002
Developer Utilities
PPM calculator
parts per million from solute mass free
POST /chem/ppm-concentration$0.002
Developer Utilities
PPM to mg/L calculator
concentration from density free
POST /chem/ppm-to-mg-per-liter$0.002
Developer Utilities
PPM to molarity calculator
convert ppm and molar mass to mol/L
POST /chem/ppm-to-molarity$0.002
Developer Utilities
PPM to PPB converter
parts per million to billion and trillion
POST /chem/ppm-to-ppb$0.002
Developer Utilities
Pseudo-first-order rate constant calculator
k' from k and excess, free
POST /chem/pseudo-first-order$0.002
Developer Utilities
Radioactive decay calculator
remaining quantity N(t)=N0·e^(−λt) free
POST /chem/radioactive-decay$0.002
Developer Utilities
Raoult's law vapor pressure calculator
P = x·P° free
POST /chem/raoult-law-vapor-pressure$0.002
Developer Utilities
Raoult's law two-component calculator
P = x₁P₁° + x₂P₂° free
POST /chem/raoult-two-component$0.002
Developer Utilities
Rate constant at new temperature calculator
Arrhenius k2, free
POST /chem/rate-constant-new-temperature$0.002
Developer Utilities
Rate from stoichiometry calculator
reaction rate from species rate and coefficient, free
POST /chem/rate-from-stoichiometry$0.002
Developer Utilities
Rate law calculator
reaction rate from k and concentrations, free
POST /chem/rate-law$0.002
Developer Utilities
Reactant mass needed calculator
grams for a target product, free
POST /chem/reactant-mass-for-product$0.002
Developer Utilities
Reaction quotient Q calculator
Qc from concentrations and coefficients, free
POST /chem/reaction-quotient$0.002
Developer Utilities
Reaction rate calculator
average rate from Δconcentration and time, free
POST /chem/reaction-rate$0.002
Developer Utilities
Reduced properties calculator
Pr, Tr, Vr from critical constants
POST /chem/reduced-state-variables$0.002
Developer Utilities
Relative vapor pressure lowering calculator
ΔP/P° free
POST /chem/relative-vapor-lowering$0.002
Developer Utilities
Reverse osmosis net driving pressure
applied P minus feed osmotic π
POST /chem/reverse-osmosis-pressure$0.002
Developer Utilities
Root-mean-square speed calculator
v_rms from molar mass and T, free
POST /chem/rms-speed$0.002
Developer Utilities
Second-order concentration calculator
remaining [A] from k, A₀, t, free
POST /chem/second-order-concentration$0.002
Developer Utilities
Second-order half-life calculator
t½ = 1/(k·[A]₀), free
POST /chem/second-order-half-life$0.002
Developer Utilities
Serial dilution calculator
concentration at each step free
POST /chem/serial-dilution$0.002
Developer Utilities
First-order shelf-life calculator
t90 for 10% decomposition, free
POST /chem/shelf-life-first-order$0.002
Developer Utilities
Solution density from mass percent
ideal mixture estimate, free
POST /chem/solution-density-from-percent$0.002
Developer Utilities
Solution freezing point calculator
Tf from solvent, molality, Kf and van't Hoff
POST /chem/solution-freezing-point$0.002
Developer Utilities
Standard cell potential calculator
E° from cathode & anode, free
POST /chem/standard-cell-potential$0.002
Developer Utilities
Stoichiometric air-fuel ratio calculator
AFR from C and H, free
POST /chem/stoichiometric-air-fuel-ratio$0.002
Developer Utilities
Mole ratio calculator
product moles from stoichiometric coefficients free
POST /chem/stoichiometry-mole-ratio$0.002
Developer Utilities
Theoretical yield calculator
moles × stoichiometric ratio, free
POST /chem/theoretical-yield$0.002
Developer Utilities
Titration equivalence point volume calculator
Veq from C and V
POST /chem/titration-equivalence-volume$0.002
Developer Utilities
Titration pH at equivalence calculator
salt C and Kb, free
POST /chem/titration-ph-at-equivalence$0.002
Developer Utilities
Van der Waals molar volume calculator
real gas Vm from P, T, a, b
POST /chem/van-der-waals-volume$0.002
Developer Utilities
Van't Hoff factor calculator
i from ions and dissociation, free
POST /chem/vant-hoff-factor$0.002
Developer Utilities
Vapor phase composition calculator
Raoult y_i from x_i and P_i^sat, free
POST /chem/vapor-phase-composition$0.002
Developer Utilities
Vapor pressure lowering calculator
ΔP = x·P° from mole fraction and pure solvent pressure
POST /chem/vapor-pressure-lowering$0.002
Developer Utilities
Volume for target molarity calculator
V = n/M from moles, free
POST /chem/volume-for-target-molarity$0.002
Developer Utilities
Volume percent to molarity calculator
M from % v/v free
POST /chem/volume-percent-to-molarity$0.002
Developer Utilities
Gas volume to moles calculator
convert STP gas volume to moles free
POST /chem/volume-to-moles-gas$0.002
Developer Utilities
Weight/volume percent calculator
% w/v from grams and mL, free
POST /chem/weight-volume-percent$0.002
Developer Utilities
Weight-volume % to molarity calculator
% w/v to M, free
POST /chem/weight-volume-to-molarity$0.002
Developer Utilities
Precipitation ion product calculator
Q vs Ksp, free
POST /chem/will-precipitate$0.002
Developer Utilities
Analogous color generator
two neighbors by hue shift angle, free palette
POST /color/analogous$0.002
Developer Utilities
CMYK to RGB converter
cyan magenta yellow key free
POST /color/cmyk-rgb$0.002
Developer Utilities
Complementary color finder
opposite hue on the wheel, free
POST /color/complementary$0.002
Developer Utilities
Color to grayscale converter
luminosity hex & gray value, free
POST /color/grayscale$0.002
Developer Utilities
Hex to HSL converter
hue, saturation, lightness free
POST /color/hex-hsl$0.002
Developer Utilities
Hex to color name
nearest CSS named color for any hex code, free
POST /color/hex-name$0.002
Developer Utilities
Hex to RGB converter
#RRGGBB to red, green, blue, free
POST /color/hex-rgb$0.002
Developer Utilities
HSL to HSV converter
convert hue saturation lightness and value both ways, free
POST /color/hsl-hsv$0.002
Developer Utilities
HSL to RGB converter
hue, saturation, lightness to red green blue 0–255, free
POST /color/hsl-rgb$0.002
Developer Utilities
HSV to RGB converter
hue, saturation, value to red, green, blue, free
POST /color/hsv-rgb$0.002