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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
Dilution Calculator
Dilution calculator free — solve C1V1=C2V2 for stock concentration, volumes, or final strength. Lab prep in your browser, no signup.
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pOH Calculator
pOH calculator free — find pOH, pH, and [OH⁻] from hydroxide concentration or strong base molarity. Instant, no signup.
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Buffer Calculator
Buffer calculator free — Henderson-Hasselbalch pH for acid and base buffers. Solve pH, pKa, or concentrations. Instant, no signup.
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Empirical Formula Calculator
Empirical formula calculator free — find simplest formula from mass % or element masses. Mole ratios in your browser, no signup.
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Molecular Formula Calculator
Molecular formula calculator free — find true formula from empirical formula and molar mass, or composition plus experimental M. No signup.
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Ideal Gas Law Calculator
Ideal gas law calculator free — solve PV=nRT for pressure, volume, moles, or temperature. atm, kPa, L, K, °C. No signup.
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Charles' Law Calculator
Charles' law calculator free — solve V1/T1=V2/T2 for volume or temperature at constant pressure. K, °C, L, mL. No signup.
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Combined Gas Law Calculator
Combined gas law calculator free — solve P1V1/T1=P2V2/T2 for any unknown. Pressure, volume, temperature units. No signup.
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Reaction Stoichiometry Calculator
Reaction stoichiometry calculator free — moles and grams from a balanced equation and known amount. Auto-balance, no signup.
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Atomic Mass Calculator
Atomic mass calculator free — IUPAC element lookup or weighted isotope average. Atomic number and u/g/mol. No signup.
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Electron Configuration Generator
Electron configuration generator free — full and noble-gas notation for any element. Aufbau rules + exceptions. No signup.
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