Make a QR code that looks like yours — and still scans.

No. QR Nook is a static page: the payload is assembled, the code is drawn, decoded for the scan check and exported by JavaScript in your browser. Nothing you type and no file you drop is sent to a server — there is no server-side part at all. After the page has loaded once, it keeps working without a network connection.

No. A dynamic code points at a short link on someone's server, which then redirects to your real address and counts the visit; the code can be re-pointed later, but it stops working if that service closes or your subscription ends. QR Nook makes static codes: the data itself is in the modules, nobody sits in between, and nothing is counted. If you need to change the destination later, encode an address you control — a page on your own domain or your own short link — and change where that points.

Error correction decides that. Level H can restore about 30 % of the modules, Q about 25 %, M 15 % and L 7 %. A logo covers modules, so at level H keep it under roughly 30 % of the code's width (which is about 9 % of its area, leaving a safety margin for print defects); the studio raises the level to H automatically when you add a logo. Never cover the three large corner squares — the scanner needs them to find the code. The scan check under the preview tells you when you have gone too far.

SVG whenever the design goes into a vector tool or to a print shop: it scales to any size without blur and stays crisp on a banner as well as a sticker. PNG is the right choice for web pages, documents, presentations and messaging apps; export it at 2× or 4× so it still looks sharp when scaled. Both exports include the frame and caption if you turned them on.

A practical rule: the code's width should be at least one tenth of the distance it will be scanned from. A code on a table card read from 25 cm can be 2.5 cm wide; a poster read from 2 m needs about 20 cm. Codes with more modules (long vCards, level H) need to be larger because each module must stay clearly printed — aim for at least 0.4 mm per module on a normal printer. Keep the quiet zone: four modules of empty background around the code.

Dark modules on a light background with strong contrast — the studio warns you when the contrast ratio drops below 3:1. Light modules on a dark background (an inverted code) are read by most modern phones but not by every older scanner, so avoid them for anything critical. Gradients are fine as long as every colour in them stays dark enough against the background; red and orange modules can fade for scanners that use a red light, which matters for barcode guns more than for phones.

Yes. The WIFI: format stores the network name and password in plain text; a phone shows a "join network" prompt, but any QR reader app will display the password itself. Treat a printed Wi-Fi code like a password written on the wall: use it for a guest network, and reprint the code when you rotate the password.

Never. A static QR code is just data drawn as modules — it has no account, no server and no subscription behind it. A code you print today will decode in twenty years exactly as it does now. The only thing that can stop working is what the data points to, for example a web page you later take down.

In this order: raise the error-correction level, make the logo smaller or turn on clearing of the modules behind it, increase the contrast between modules and background, and widen the quiet zone to at least four modules. Very ornate module shapes on a long payload can also confuse decoders — try rounded or square modules. The check uses the jsQR decoder at 600 px on white paper, which is close to a phone camera but not identical, so a real scan of the printed result is still the final test.