About QR Cat
QR Cat is a small team making free online QR code tools. We believe a tool should be honest — no expiry traps, no quietly harvesting your data, no ads stamped on your code.
Four promises
- Free forever — no trial window, no “your code expired, pay to keep it,” every feature open.
- Never expires — we make static codes; the content lives in the pattern itself, so your code scans even if we go offline.
- Local-first — the QR is built in your browser; your content is never uploaded, never tracked.
- No watermark, no sign-up — download and go, no logo on your code, no email wall.
How it works (the honest version)
A lot of “free” QR sites hand you a dynamic code: the code is just a short redirect link, and the real content lives on their server. Stop paying and the link dies — the code you printed on a flyer, menu or business card becomes a dead square.
QR Cat does the opposite. We use open-source libraries to encode your content into a static code, right in your browser. The black-and-white modules are your URL / WiFi / contact card — no server hop in between, and decoding happens locally too. Because there's no server cost, “free forever, never expires” isn't a marketing line — it's just what the architecture allows.
Static vs dynamic QR codes explained: why static never expires
A static QR code encodes the content (a URL, text, WiFi or contact card) directly into the black-and-white pattern itself — scanning returns it instantly, with no server redirect in between. That's why a static code is permanent and never expires: it keeps working even if the site that made it shuts down. A dynamic QR code instead encodes only a short redirect link, with the real content stored on a provider's server — which lets you edit it later and track scans, but means the code dies the moment you stop paying or the provider goes away. Choose static for “make once, works forever”; choose dynamic only if you need to change the content later or track scan analytics. QR Cat makes static codes only, because they're the most honest choice and right for most people.
Engines & standards we build on
We don't reinvent the maths — we stand on well-tested, open libraries so the codes follow the spec exactly. Codes are generated with qr-code-styling and conform to the ISO/IEC 18004 QR Code standard (the same one your phone camera expects), including its error-correction levels L/M/Q/H. Decoding and our scannability test use ZXing (via zxing-wasm) — the open-source decoder lineage that countless phone cameras and apps rely on — so a code that passes our test is being read by the same kind of engine that'll read it in the wild. Barcodes use JsBarcode for EAN/UPC/Code 128 and friends. All of it runs in your browser via WebAssembly and JavaScript; you can open your browser's network tab and confirm nothing leaves your device.
Methodology and facts on this page last reviewed .
Who writes and checks this
Ziyao Wang· Builder & editor, QR Cat
I build QR Cat's tools and write these guides, then verify every claim against the ISO/IEC 18004 QR standard and by decoding real codes with the same ZXing engine phone cameras use.
Frequently asked questions
Is QR Cat really free forever?
Yes. Your QR codes are generated locally in your browser, so our server cost is essentially zero — there's no trial to expire. Generating, recoloring, adding a logo, exporting PNG / SVG and decoding from an image are all free, with no sign-up.
Is my content (URLs, WiFi passwords, contact details) uploaded?
No. The QR code is computed on your device. Whatever you type never touches our servers, and we don't track or store it. Decoding an image happens locally too.
Will the QR codes I make stop working later?
No. We generate static codes — your content is encoded directly into the black-and-white pattern, with no server redirect in between. Even if QR Cat shut down tomorrow, the codes you printed would still scan.
Can I use QR Cat for commercial use?
Yes. The QR codes you make with QR Cat are yours to use commercially — on product packaging, menus, posters, business cards and ads. No attribution, no licensing, no fees.
Does QR Cat work offline?
Yes. After the page loads once, generating and decoding QR codes happens entirely in your browser with no server dependency — so you can keep making and reading codes even if you go offline afterwards.
Is QR Cat open source?
QR Cat itself isn't open source yet, but it's built on well-established open-source libraries (qr-code-styling to generate, ZXing to decode) and runs entirely in your browser — you can confirm in your browser's dev tools that nothing is uploaded.
Updated · QR Cat team