Metric Converter is a free online toolkit for two related jobs: converting measurement units and converting file formats. On the unit side it covers 188 units grouped into 15 categories, from everyday length and mass conversions like centimetres to inches or kilograms to pounds through to temperature, volume, area, time, speed, energy, pressure, power, angle and digital storage, plus practical extras such as fuel economy and fabric weight. That adds up to 1,162 selected unit conversion pairs.
The file side publishes 93 conversion tools, converting between common image and document formats such as JPEG to PNG or WebP and PNG to PDF. What sets the site apart is how it processes them: unit maths is handled with plain JavaScript factors, while file conversions run entirely in the browser with client-side JavaScript, browser APIs and WebAssembly. Your files never leave the device, and the data is discarded when the tab closes.
There is no account, no watermark and no payment. Each tool page shows the exact conversion factor and formula used, alongside reference tables for the units involved, and the site also offers specialist collections for areas like sewing measurements, fabric yardage and button ligne conversions.
