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Kostenlose 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
Sample Size Calculator
Calculate sample size for surveys, mean estimates, A/B tests, and two-group comparisons. Set confidence level, power, margin of error, and effect size. Step-by-step formulas. Free, browser-based.
Used 0 timesUpdated never
Lab Timer
Countdown and stopwatch timer for lab work. Presets for 1, 5, 10, 15, 30, and 60 minute incubations. Lap times, audio alert on completion. Free, runs in your browser.
Used 0 timesUpdated never
Serial Dilution Calculator
Plan serial dilutions with fold factors, transfer volumes, and concentration at each step. Find how many steps to reach a target, or set up CFU plate-count dilutions. Full table with log₁₀ values and lab procedure. Free, browser-based.
Used 0 timesUpdated never
Experiment Randomizer
Randomize experiment run order, assign samples to treatment groups, or shuffle replicate blocks. Fisher–Yates shuffle with optional seed for reproducible lab randomization. Free, browser-based.
Used 0 timesUpdated never