QR code generator
Turn text or a URL into a downloadable QR code
Type or paste something above to build a QR code.
How this works, and what it will not do
The encoder is written from ISO/IEC 18004 and runs in this tab: the version tables, Reed–Solomon correction over GF(256), the eight mask patterns and their penalty scoring, and the BCH-protected format and version information. Nothing is uploaded and no image service is called, which is the point — a QR code often carries a URL with a token in it, and that is not a thing to hand to a stranger's server.
All 40 versions and all four correction levels are supported. Deliberately absent: Kanji mode, which would need a Shift-JIS table (Japanese text still encodes correctly, as UTF-8 in byte mode, just less densely); ECI headers, so byte mode carries bare UTF-8, which is what scanners assume in practice; and mixed-mode segmentation, so a payload of mostly letters with a long run of digits in it may take one version more than a commercial encoder would need.
Print it larger than you think you need to, keep the light border, and test the actual artefact with an actual phone before you print a thousand of them.