免費線上工具
268+ free online tools for PDF, images, SEO, developers, color, and productivity. Fast, browser-based, and private — no signup, no installs, no limits. Search above or browse by category below.
Total tools26810.8K total uses
Categories13Active categories
Most usedJSON Formatter4.1K uses
Recently addedExperiment RandomizerNewest tool
Mole Calculator
Mole calculator free — convert between grams, moles, and particles using molar mass. Instant chemistry stoichiometry in your browser, no signup.
Used 1 times•Updated 45 minutes ago
Solution Concentration Calculator
Solution concentration calculator free — molarity, mass/volume, and dilution (C1V1=C2V2). Chemistry lab prep in your browser, no signup.
Used 1 times•Updated 29 minutes ago
pH Calculator
pH calculator free — find pH, pOH, and ion concentrations from [H⁺], [OH⁻], or strong acid/base molarity. Instant, no signup.
Used 1 times•Updated 28 minutes ago
Percent Yield Calculator
Percent yield calculator free — find % yield, actual yield, or theoretical yield in grams or moles. Stoichiometry lab prep, no signup.
Used 1 times•Updated 34 minutes ago
Periodic Table Explorer
Interactive periodic table with element details, atomic mass, and electron configuration for all 118 elements.
Used 1 times•Updated 35 minutes ago
Oxidation Number Calculator
Find oxidation numbers in chemical formulas using standard rules — H2SO4, KMnO4, NH3, and polyatomic ions. Free, instant, browser-based.
Used 1 times•Updated 22 minutes ago
DNA to RNA Converter
Convert DNA to RNA — replace T with U on the coding strand, or transcribe from the template strand. FASTA support. Free, instant, browser-based.
Used 1 times•Updated 34 minutes ago
RNA to Protein Translator
Translate RNA to protein with the standard genetic code — reading frames, AUG start, stop codons, and codon table. Free, instant, browser-based.
Used 1 times•Updated 16 minutes ago
Integral Calculator
Compute symbolic indefinite integrals with step-by-step rules. Supports polynomials, trig, exp, and 1/x.
Used 1 times•Updated 37 minutes ago
Vector Calculator
Compute 2D and 3D vector operations — add, subtract, dot product, cross product, magnitude, unit vector, angle, and projection — with steps.
Used 1 times•Updated 38 minutes ago
Prime Number Generator
Generate prime numbers in a range or list the first N primes using the Sieve of Eratosthenes with copy-ready output.
Used 1 times•Updated 5 minutes ago