Converters
Tools for converting values between formats. All processing happens in your browser, so your data is never uploaded.
- Unix Timestamp ConverterConvert a Unix timestamp to a readable date or the other way round. The unit is detected automatically and every result shows its time zone.
- Case ConverterPaste text to see it in every case at once, from camelCase and snake_case to Title Case and sentence case. Everything runs in your browser.
- Binary ConverterConvert a number between binary, octal, decimal and hexadecimal, or convert text to binary and back. Values stay exact at any size, including well beyond 64 bits.
- Unit ConverterConvert between metric and imperial units for length, weight, temperature, area, volume, speed, data and time. Every conversion uses the exact defined factor, so results are not thrown off by floating-point error.
- Image ConverterConvert an image between PNG, JPG and WebP. The file is decoded and re-encoded inside this page, so it never leaves your device and keeps working with no connection.
- Image ResizerResize an image to exact pixels, a percentage, or a maximum longest edge. The resizing happens in this page, so the file never leaves your device.
Choose a conversion tool
Use the timestamp converter to read a Unix time as a date in your own zone and in UTC, the base converter for binary, octal, decimal and hexadecimal with exact arithmetic, and the case converter to move an identifier between camelCase, snake_case, kebab-case and the rest.
Use the unit converter for length, mass, volume, temperature, data and time, and the image converter and resizer when the file itself has to change format or dimensions. Images never leave your device: the decoding and re-encoding happen in the browser.
A value, a representation and a unit
Most of the work in this category is one of two things. Either the value stays the same and only its representation changes - 255 written as 0xFF, a name written in snake_case - or the value is genuinely restated in another unit, as when kilometres become miles or a Celsius reading becomes Fahrenheit.
The distinction matters because the first kind is always exactly reversible and the second usually is not. Converting a number to hexadecimal and back gives you the same number; converting an image to JPG and back does not give you the same image.
Lossless, lossy and approximate
Base and case conversion are lossless in principle, with one exception worth knowing: an acronym loses its boundaries when it is lowercased, so HTTPServer becomes http_server and converts back as HttpServer. Most metric-to-imperial factors are exact by definition rather than approximate, so those conversions carry no error at all.
The genuinely lossy ones are the image tools, where every lossy re-encode discards a little more, and anything involving calendar months or years, which have no exact length and are reported as averages. Where a result is rounded rather than exact, it says so.
Check the edges before you trust the middle
Conversions fail at boundaries far more often than in the ordinary range. A Unix timestamp in seconds handed to something expecting milliseconds lands in 1970; a 64-bit identifier converted through an ordinary JavaScript number loses precision above about nine quadrillion; an image enlarged past its source resolution gains pixels that were never photographed.
The tools here are built to be honest at those edges - arbitrary-precision arithmetic for bases, an explicit unit for timestamps, a refusal rather than a silent blank image when a file is too large for the browser's canvas. When you are checking someone else's conversion, the boundary case is where to start.