Units, colors, timestamps

    Convert in one step, no formulas needed.

    Metres to miles, HEX to OKLCH, epoch seconds to your local time zone. Enter a value once and read it in every format you need.

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    Unit Converter

    Convert length, weight and temperature measurements with instant live calculations.

    Color Converter

    Convert colors instantly between HEX, RGB, RGBA, HSL, HSLA and OKLCH formats with an interactive color palette.

    Unix Time Converter

    Convert Unix timestamps to readable dates and epoch time instantly.

    How It Works

    Three converters for the translations that trip people up: metric and imperial, one color format to another, and an epoch number to a date you can actually read.

    When the number is right but the format is wrong

    Most conversion mistakes are not maths mistakes. They come from mixing up seconds and milliseconds, assuming a color format a design tool does not use, or forgetting that temperature has an offset. These three converters take care of the translation and let you copy the result straight into your work.

    The three converters

    • Unit Converter covers length (metres, kilometres, centimetres, millimetres, miles, yards, feet, inches), weight (kilograms, grams, milligrams, metric tons, pounds, ounces) and temperature (Celsius, Fahrenheit, Kelvin). Type in any field and the others update as you go. It uses exact international definitions, such as 0.0254 metres per inch.
    • Color Converter accepts HEX, RGB, RGBA, HSL, HSLA and OKLCH, detects the format you paste and shows all six outputs. A built-in picker and an 11-step palette generator (Tailwind scale, shades, tints and tones) help you explore variations.
    • Unix Time Converter turns timestamps into dates and dates back into timestamps, in any time zone, with ISO 8601 or local formatting. It reads seconds and milliseconds automatically and shows the current Unix time live.

    Mistakes worth avoiding

    Seconds versus milliseconds. A 10-digit timestamp is in seconds and a 13-digit one is in milliseconds. JavaScript's Date.now() returns milliseconds while many backends expect seconds, which is how dates end up in 1970 or thousands of years away.

    Color spaces. OKLCH is designed so that equal changes in lightness look equally different to the eye, which HSL does not guarantee. That makes it a good fit for modern design tokens, while HEX and RGBA remain the safe choice for older tools.

    Temperature. Celsius, Fahrenheit and Kelvin do not share a zero point, so a simple multiplication gives the wrong answer. Let the converter apply the offset.

    Frequently Asked Questions

    Common questions about our free converters tools and calculations.

    Conversions use standard international definitions, for example exactly 0.0254 metres per inch and 0.45359237 kilograms per pound, so results stay consistent to many decimal places. The Unit Converter covers length, weight and mass, and temperature. It does not cover volume, area or currency.

    HEX, RGB, RGBA, HSL, HSLA and OKLCH. Paste any one of them and the tool detects it and fills in the rest, with copy buttons for CSS-ready values. HEX output is six characters, so transparency is carried by the RGBA and HSLA values instead.

    OKLCH describes a color by lightness, chroma and hue in a way that matches human perception more closely than HSL. Changing lightness gives an even visual step, which is useful for building accessible palettes and design tokens. Use HEX or RGBA when you need maximum compatibility with older tools.

    Count the digits. Ten digits means seconds and thirteen means milliseconds. The Unix Time Converter detects which one you pasted and converts correctly, then shows the date in the time zone you choose, in ISO 8601 or local format. You can also convert a date back into both seconds and milliseconds.

    No. Every conversion is calculated in your browser, so the numbers, colors and timestamps you enter are not uploaded or stored. The Reset button on each tool clears the fields.