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
Exoplanet Habitability Calculator
Assess exoplanet habitability with habitable zone, equilibrium temperature, and Earth Similarity Index (ESI). Presets for Earth, Proxima b, and Kepler-186f. Free, browser-based.
Used 0 times•Updated never
Constellation Finder
Find constellations by RA/Dec coordinates, search all 88 IAU constellations by name, or list what's visible tonight from your location. Free, browser-based.
Used 0 times•Updated never
Earthquake Magnitude Converter
Convert between earthquake magnitude scales — Mw, Ms, ML (Richter), mb, and Md. Estimates seismic moment, energy in joules, and TNT equivalent. Free, browser-based.
Used 0 times•Updated never
Richter Scale Calculator
Calculate Richter magnitude from seismograph amplitude and distance, explore effects and energy for any ML value, or compare two magnitudes. Free, browser-based.
Used 0 times•Updated never
Wind Chill Calculator
Calculate wind chill (feels-like temperature) from air temperature and wind speed. Uses the official NWS / Environment Canada 2001 formula with frostbite risk guidance. Free, browser-based.
Used 0 times•Updated never
Dew Point Calculator
Calculate dew point from temperature and relative humidity, or find RH from temperature and dew point. Shows vapor pressure, absolute humidity, and comfort level. Free, browser-based.
Used 0 times•Updated never
Humidity Calculator
Calculate relative humidity, dew point, wet-bulb temperature, vapor pressure, absolute humidity, and mixing ratio from dry-bulb readings. Free, browser-based.
Used 0 times•Updated never
Air Density Calculator
Calculate air density from temperature, pressure, and humidity, or from altitude. Shows kg/m³, virtual temperature, speed of sound, and comparison to sea-level standard. Free, browser-based.
Used 0 times•Updated never
Altitude Pressure Calculator
Convert between altitude and atmospheric pressure using the barometric formula or ISA standard atmosphere. Pressure in hPa, inHg, kPa, and more. Free, browser-based.
Used 0 times•Updated never
Soil Density Calculator
Calculate soil bulk density, moisture content, porosity, and void ratio from sample mass and volume. Supports metric (g, cm³) and imperial (lb, ft³). Free, browser-based.
Used 0 times•Updated never
Carbon Footprint Calculator
Estimate your annual carbon footprint from car travel, flights, home electricity, and natural gas. Compare to global averages with regional grid factors. Free, browser-based.
Used 0 times•Updated never
Rainfall Calculator
Calculate rainfall volume from catchment area and depth, estimate storm runoff with a runoff coefficient, or compute rainfall intensity (mm/hr). Metric and imperial units. Free, instant, browser-based.
Used 0 times•Updated never