Gratis online tools
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
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 times•Updated 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 times•Updated 47 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 times•Updated 29 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 times•Updated 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 times•Updated 58 minutes ago
Cell Division Calculator
Calculate cell count after binary fission — solve for N, N₀, divisions, generation time, or elapsed time with step-by-step growth table. Free, browser-based.
Used 1 times•Updated 38 minutes ago
Derivative Calculator
Compute symbolic derivatives of functions with step-by-step rules. Supports polynomials, trig, ln, exp, and more.
Used 1 times•Updated 46 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 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 times•Updated 4 minutes ago
Probability Calculator
Calculate basic, complement, union, intersection, conditional, and binomial probabilities with formulas and step-by-step work.
Used 1 times•Updated 29 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 times•Updated 5 minutes ago
Standard Deviation Calculator
Calculate sample and population standard deviation and variance from any data set with squared-deviation steps.
Used 1 times•Updated 4 minutes ago