免费在线工具
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
BMR Calculator
Calculate basal metabolic rate (BMR) with Mifflin-St Jeor, Harris-Benedict, or Katch-McArdle — compare formulas and TDEE estimates. Free, instant, browser-based.
Used 0 times•Updated never
Blood Type Inheritance Calculator
Predict child blood types from parent ABO and Rh types — Punnett squares, probabilities, and combined outcomes like A+ or O−. Free, instant, browser-based.
Used 0 times•Updated never
Phylogenetic Tree Generator
Build phylogenetic trees from distance matrices, aligned DNA sequences (UPGMA), or Newick strings — SVG diagram, ASCII tree, and export. Free, browser-based.
Used 0 times•Updated never
Mutation Simulator
Simulate DNA/RNA mutations — substitutions, insertions, deletions, and seeded random SNPs with highlighted output and mutation log. Free, browser-based.
Used 0 times•Updated never
Microscope Magnification Calculator
Calculate microscope total magnification, field of view from FN, and actual specimen size from image measurements — eyepiece × objective. Free, browser-based.
Used 0 times•Updated never
Equation Solver
Solve linear and quadratic equations step by step. Enter expressions like 2x + 3 = 7 or x^2 - 5x + 6 = 0.
Used 0 times•Updated never
Quadratic Equation Solver
Solve ax² + bx + c = 0 with the quadratic formula. Get roots, discriminant, vertex, and step-by-step work.
Used 0 times•Updated never
Polynomial Solver
Find roots of polynomials up to degree 6. Enter coefficients or an equation like x³ − 6x² + 11x − 6 = 0.
Used 0 times•Updated never
Derivative Calculator
Compute symbolic derivatives of functions with step-by-step rules. Supports polynomials, trig, ln, exp, and more.
Used 0 times•Updated never
Integral Calculator
Compute symbolic indefinite integrals with step-by-step rules. Supports polynomials, trig, exp, and 1/x.
Used 0 times•Updated never
Limit Calculator
Evaluate limits numerically with one- and two-sided approaches. Supports finite points and ±∞.
Used 0 times•Updated never