QR Code Generator

The QR code that still works in ten years

Most free QR generators online produce a code that does not contain your link. It contains theirs. Scanning it goes to their server, which looks up where you wanted to send people and forwards them on.

Why that matters more than it sounds

Redirection is sold as a feature, usually called a "dynamic" code, and it genuinely allows one useful thing: changing the destination after the code is printed. It also creates three problems that nobody mentions on the way in.

The code dies when the service does. If that company shuts down, changes its pricing, or simply lets a domain lapse, every code ever printed stops working. Not degrades — stops. There is no way to fix a sticker already on ten thousand products.

It usually expires anyway. Free tiers frequently cap scans or expire after a trial, and the code that worked at the launch event is dead by the time the posters are up.

Every scan is logged by a third party. Who scanned, when, roughly where, on what device. That data is the actual business model.

A code made here contains your URL, your network name, your phone number. There is no lookup, no service in the middle and nothing to expire, because after the image is downloaded this page has no further part in it. The trade is real and worth stating: you cannot change where it points afterwards. If that matters, point the code at a page you control and change what is on that page — which gets you the flexibility without handing anybody a switch to your printed material.

Error correction, and the room it buys

Every QR code carries redundancy, so it can be read while partly damaged. The level you choose decides how much:

Higher correction means more modules for the same data, so the code looks denser and needs to be printed larger to stay readable. Medium is right unless you have a reason.

The white border is not decoration

The blank margin around a QR code — the "quiet zone" — is part of the specification. It is how a reader finds where the code begins. The standard asks for four modules, and codes cropped tight to the edge are one of the most common reasons a scan fails on an otherwise perfect image.

If you are placing a code on a busy background, keep that border and keep it in a plain colour. It is not wasted space.

Colours: contrast, and which way round

Two rules, and the second surprises people.

The first is contrast: readers need a clear difference between the code and its background. Pale grey on white fails in poor light even when it looks fine on your screen.

The second is direction. Dark code on a light background reads reliably; light code on dark does not, because many readers assume the darker modules are the data. Inverted codes work on some phones and fail on others, which is the worst possible outcome — it looks fine when you test it and fails for a quarter of your audience. This tool warns you when the colours are inverted or too close, rather than letting you find out from a printed run.

PNG or SVG

PNG is an image of a fixed size: right for a screen, an email, a slide, or anything printed small at a size you already know.

SVG describes the squares mathematically, so it is sharp at any size at all — a business card or the side of a building, from the same file. If the code is going to a printer, send the SVG. It is also far smaller, and it is the format a designer will ask for.

Wi-Fi codes, and the detail most tools get wrong

A Wi-Fi QR code is a small text format listing the network name, the security type and the password. Phones read it natively and join without anybody typing anything.

The detail worth knowing: characters like ; , : " and \ have to be escaped inside that format. A password containing a semicolon, encoded by a tool that skips this, produces a code that scans perfectly and then fails to connect — which is almost impossible to debug from the outside. This one escapes them.

What happens after somebody scans a Wi-Fi code

This is the part that surprises people, so it is worth setting out. A QR code is text and nothing else. It carries the network name, the security type and the password, and hands them to the phone. It cannot open an app, cannot change a setting, and cannot make anything connect — no QR code can, whatever it contains. Everything after the scan is the phone’s decision.

On an iPhone the camera shows a banner. Tapping it asks Join network?, and confirming saves the network and starts trying to associate — while staying in the camera. It does not jump to Settings. There is no way to make it, and a code that claimed to would be lying about what a code can do. Android behaves the same way from its own scanner.

So the join happens quietly in the background and can take a few seconds. If the phone is on a working mobile connection it is in no hurry about it. The status bar switching from 5G to the Wi-Fi symbol is what tells you it finished.

How to tell whether the code actually worked

There is a clean test, and it is worth knowing because the symptom of success looks a lot like the symptom of failure.

Open Settings, find the network in the list, and tap it. If it connects without asking you for the password, the code worked. The phone only has that password because the code gave it, so a password-free join is proof the whole thing went through. What did not happen was the automatic association, which is a separate matter and usually only means the phone had not got round to it.

If it does ask for the password, then the code genuinely failed, and there are three usual reasons:

One thing worth knowing about the 2.4 and 5 GHz bands: if your router publishes them as two separate names, the code carries whichever one you typed. A phone standing somewhere with weak 5 GHz coverage may sit on mobile data rather than take it, which looks like the code failing when it is really the radio choosing.

Nothing you type is sent anywhere

The encoder runs in your browser. Your link, your network password and your phone number are turned into an image on your own machine and never transmitted.

Wi-Fi codes make that concrete: generating one elsewhere means typing your home or office password into somebody else's website. Here it goes into an image and nowhere else.