Unit Lens — Auto Unit Converter

Automatically converts measurements on any web page (length, mass, temperature, volume, speed, area) into the units you prefer.

Unit Lens automatically converts the measurements on any web page into the units you actually think in — instantly, as the page loads. Reading a US recipe but you think in metric? Browsing a hiking blog in miles when you want kilometers? Checking a product spec in pounds when you'd rather see kilograms? Unit Lens rewrites those values in place so you never have to stop and do the math. WHAT IT CONVERTS • Length / distance — mm, cm, m, km, in, ft, yd, mi • Mass / weight — mg, g, kg, t, oz, lb, st • Temperature — °C, °F, K • Volume — ml, l, fl oz, cup, pt, qt, gal • Speed — m/s, km/h, mph, knots • Area — cm², m², km², ha, sq ft, acre, sq mi HOW IT WORKS Pick your preferred unit for each measurement type from the toolbar popup. Unit Lens scans each page you open and converts matching measurements automatically. Converted values get a subtle dotted underline — hover over one any time to see the original. You're always in control: • Turn any measurement type on or off individually. • Flip the master switch to pause all conversions. • Your preferences sync across your signed-in Chrome devices. PRIVATE BY DESIGN Everything happens locally in your browser. Unit Lens does not collect, store, or transmit any personal data, does not track your browsing, and contains no remote code or analytics — it only ever stores your unit preferences. SMART DETECTION Unit Lens is careful about what it converts. It won't mistake "5G", "4K", or "$20K" for measurements, and it leaves text fields, code blocks, and editable areas untouched. Install Unit Lens and read the web in the units that make sense to you.