Free Online Calculators, Converters & Developer Tools
Explore 5,154 free online calculators, converters, and developer tools for math, unit conversions, text, and everyday tasks. Use them in your browser with no registration required.
Explore Tools by Category
Find the right tool for the task, from unit conversions and calculations to text, development, generators, and everyday essentials.
- 📏 Unit Converters Convert everyday and specialist measurements across metric, imperial, and engineering units. 4,998 tools →
- ➗ Math Tools Solve arithmetic and trigonometry problems, convert number bases, and check data integrity. 91 tools →
- 🔤 Text & Encoding Tools Format, analyse, count, and encode text with quick tools for common text and data tasks. 27 tools →
- 💻 Developer & Design Tools Convert colors, work with timestamps, and check browser or device information. 27 tools →
- 🎲 Generators Create passwords, random values, colors, codes, and dice rolls for work or play. 7 tools →
- 🛠️ Everyday Tools Handle daily tasks like calculating discounts, keeping tallies, and making simple decisions. 4 tools →
Popular Unit Converters
- Celsius To Fahrenheit Converter Convert Celsius (°C) to Fahrenheit (°F) or Fahrenheit to Celsius with offset formulas and absolute-zero validation.
- Fahrenheit To Celsius Converter Convert Fahrenheit (°F) to Celsius (°C) or Celsius to Fahrenheit with offset formulas and absolute-zero validation.
- Kilometers To Miles Converter Convert kilometers to miles or miles to kilometers using the exact international mile definition.
- Miles To Kilometers Converter Convert miles to kilometers or kilometers to miles using the exact international mile definition.
- Kilograms To Pounds Converter Convert kilograms to pounds or pounds to kilograms using the exact international avoirdupois pound definition.
- Pounds To Kilograms Converter Convert pounds to kilograms or kilograms to pounds using the exact international avoirdupois pound definition.
- Centimeters To Inches Converter Free online Centimeters To Inches Converter. Convert lengths between centimeters and inches by selecting a direction, with a conversion formula, reference table, and real-time calculation.
- Inches To Centimeters Converter Free online Inches To Centimeters Converter. Convert lengths between inches and centimeters by selecting a direction, with a conversion formula, reference table, and real-time calculation.
- Feet To Meters Converter Convert feet to meters or meters to feet using the exact international foot definition.
- Liters To US Gallons Converter Convert liters to US liquid gallons or US gallons to liters using the exact US gallon definition.
- US Gallons To Liters Converter Convert US liquid gallons to liters or liters to US gallons using the exact US gallon definition.
- Unix Timestamp To Time Converter Free online Unix timestamp converter. Convert Epoch timestamps into human-readable date and time formats instantly.
Number Base & Color
- Decimal To Binary Convert a signed decimal integer to binary (base 2). Spaces and underscores are ignored; a leading plus or minus sign is allowed.
- Binary To Decimal Convert an unsigned binary integer to decimal (base 10). Spaces and underscores are ignored; the binary digit count is shown.
- Decimal To Hexadecimal Convert a signed decimal integer to uppercase hexadecimal (base 16). Spaces and underscores are ignored; a leading plus or minus sign is allowed.
- Hexadecimal To Decimal Convert an unsigned hexadecimal integer to decimal (base 10). Hex digits are case-insensitive; spaces and underscores are ignored.
- RGB To HEX Free online RGB to HEX converter. Convert RGB color values into hexadecimal color codes with instant visual color preview.
- HEX To RGB Free online HEX to RGB converter. Convert hexadecimal color codes into RGB/RGBA values with alpha transparency support.
Text & Encoding
- Word Counter Free online word counter tool. Count words, characters, sentences, and paragraphs in your text with instant statistics.
- Uppercase Converter Free online uppercase converter. Transform any text into all uppercase capital letters instantly with one click.
- Lowercase Converter Free online lowercase converter. Convert capitalized text into lowercase letters instantly with real-time text processing.
- Base64 Encoder Encode UTF-8 text to standard Base64 in your browser.
- Base64 Decoder Decode standard Base64 as UTF-8 text in your browser. Unambiguous inputs without terminal padding are accepted.
- URL Encoder Free online URL encoder tool. Percent-encode special characters in URLs and query strings for web safe transmission.
Generators & Math
- Password Generator Free online secure password generator. Create strong, customizable passwords with letters, numbers, and symbols.
- Random Number Generator Free online random number generator. Generate true pseudo-random numbers within any custom minimum and maximum range.
- Current Unix Timestamp Live Unix timestamp checker. View current Epoch time in seconds and milliseconds with real-time countdown updates.
- Square Root Calculator Free online square root calculator. Calculate the square root of any positive number instantly with high precision.
- Prime Number Checker Free online prime number checker and calculator. Test if any positive integer is a prime or composite number instantly.
- Random Color Generator Free online random color generator. Generate random HEX, RGB, and HSL colors with visual preview and one-click copy.