Color Picker
Pick a colour and read off its HEX, RGB and HSL values.
Generate CODE128, EAN-13, CODE39 and more, as SVG or PNG.
Nine formats including CODE128, EAN-13 and CODE39, with check digits computed to spec (EAN-13 takes 12 digits and computes the 13th). The input rules for each format are stated in the UI.
Nine formats, each with its content requirement shown in the UI: EAN-13 / UPC-A / ITF-14 take only the first 12 / 11 / 13 digits (**the check digit is computed**), Code39 accepts uppercase letters and a few symbols, and Pharmacode is an integer from 3 to 131070.
Two outputs: **copy the SVG** (vector — stays crisp when printed or scaled) or **download a PNG** (pixel size equals the preview, so raise bar width and height before printing).
Colours and the quiet zone are fixed (dark bars on white with 10 units of margin): both decide whether a scanner can read the code, so they are not exposed as options.
Pick a format and type the content
The UI lists the characters that format allows and reports a mismatch instead of drawing an unreadable code.
Adjust bar width and height
Bar width defaults to 2 and height to 80; use 3 or more for print, the defaults are fine on screen.
Copy the SVG or download the PNG
SVG for design and web work, PNG when you need a bitmap (Word, chat apps).
The 13th is a check digit: multiply the odd positions by 1 and the even ones by 3, sum, then subtract the units digit from 10 (if the sum ends in 0 the check digit is 0). Computing it by hand invites errors that the scanner would reject anyway — the tool and the reader use the same algorithm.
Check three things in order. (1) Is the bar width and height large enough? A PNG is the preview size, so scaling it up only blurs it — use the SVG or set bar width to 3+. (2) Is the quiet zone intact? Scanners need the margin to find the edges. (3) Is the print contrast high enough? Avoid coloured paper and ink-saving modes.
Pick a colour and read off its HEX, RGB and HSL values.
Check foreground and background contrast against accessibility thresholds.
Build CSS linear and radial gradients visually, then copy the code.
Tune a box shadow visually and copy the CSS.
Convert physical units across length, weight, volume and more.
Convert between bytes, KB, MB, GB and TB.