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Công cụ trực tuyến miễn phí

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
Periodic Table Explorer
Interactive periodic table with element details, atomic mass, and electron configuration for all 118 elements.
Used 1 timesUpdated 5 minutes ago
DNA Reverse Complement
Get the reverse complement of a DNA or RNA sequence — A↔T/U, G↔C with GC content and FASTA support. Free, instant, browser-based.
Used 1 timesUpdated 27 minutes ago
Codon Finder
Find codons in RNA or DNA — search AUG, stop codons, scan reading frames, and view codon frequencies. Free, instant, browser-based.
Used 1 timesUpdated 48 minutes ago
Genetic Probability Calculator
Calculate offspring genotype and phenotype probabilities from Punnett squares — monohybrid and dihybrid crosses with instant results. Free, browser-based.
Used 1 timesUpdated 30 minutes ago
Punnett Square Generator
Generate Punnett squares for monohybrid and dihybrid crosses with custom trait names, parent labels, and genotype or phenotype ratios. Free, instant, browser-based.
Used 1 timesUpdated 47 minutes ago
Population Growth Calculator
Calculate population growth with exponential and logistic models — solve for N, growth rate r, time, or N₀ with projections and doubling time. Free, browser-based.
Used 1 timesUpdated 59 minutes ago
Derivative Calculator
Compute symbolic derivatives of functions with step-by-step rules. Supports polynomials, trig, ln, exp, and more.
Used 1 timesUpdated 47 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 timesUpdated 34 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 timesUpdated 5 minutes ago
Probability Calculator
Calculate basic, complement, union, intersection, conditional, and binomial probabilities with formulas and step-by-step work.
Used 1 timesUpdated 30 minutes ago
Regression Calculator
Fit a linear regression line to (x, y) data — slope, intercept, equation, correlation r, R², and predictions with step-by-step work.
Used 1 timesUpdated 6 minutes ago
Standard Deviation Calculator
Calculate sample and population standard deviation and variance from any data set with squared-deviation steps.
Used 1 timesUpdated 5 minutes ago