About WiFi QR Codes
Typing a WiFi password on a phone's on-screen keyboard is a small, specific kind of annoyance - long random strings of mixed-case letters, numbers, and symbols, entered on glass with autocorrect fighting you the whole way. A WiFi QR code exists entirely to eliminate that moment. It works by encoding your network's credentials into a specially formatted string, something like WIFI:T:WPA;S:YourNetworkName;P:YourPassword;;, that both iOS and Android recognize natively as a request to join a network rather than a link to open in a browser. Instead of launching a browser, the phone surfaces a "Join Network" prompt with the network name and password already filled in, and the person just taps to confirm. No app, no typing, no risk of mishearing a password shouted across a noisy cafe.
The "T" field in that string specifies the security type, and getting it right matters more than any other part of the code. WPA and WPA2 - the encryption standards used by the overwhelming majority of routers sold over the last decade or more - share the same "WPA" designation in this format. Older networks still running the considerably weaker WEP standard use "WEP" instead, and a fully open network with no password at all uses "nopass," with the password field left empty. Selecting the wrong security type here is one of the single most common reasons a generated WiFi code fails silently - the code scans fine, the prompt appears, and the connection attempt simply fails, with most phones giving no clearer explanation than "incorrect password" even when the password itself was typed correctly.
One real limitation worth knowing before you rely on this for a business network: the standard WIFI: string format was designed around the personal, password-based version of WPA/WPA2, the kind of single shared password most home and small-business routers use. It doesn't cleanly support WPA2-Enterprise or WPA3-Enterprise setups, the kind larger organizations use with individual per-user logins issued through a RADIUS server rather than one shared password - if your office network is configured that way, a simple WiFi QR code generally won't be able to join it on its own, and IT-managed enrollment is usually still required for that kind of setup.
This type has become a quiet fixture of hospitality and shared spaces precisely because "what's the WiFi password" is one of the most universally asked questions in any space that offers it. A cafe might tuck a small table tent with the code next to the sugar packets. An Airbnb host might laminate a card for the welcome folder. A co-working space might post a sticker at the front desk. A wedding venue might print a card at each table so guests can post photos throughout the night without burning through their own mobile data. A guesthouse owner might frame the code directly above the router itself, which is usually the exact spot a frustrated guest ends up standing in front of once their phone refuses to connect on its own.
Getting the network name and password exactly right is worth double and triple-checking, since both fields are case-sensitive and a single wrong character - a lowercase "l" typed for an uppercase "I," a missed underscore - produces a code that looks completely ordinary and scans without any error, but silently fails to connect every single time. It's a common enough mistake that testing the generated code yourself, on an actual device, before printing or laminating anything is worth the thirty seconds it takes.
Security is worth thinking about deliberately rather than as an afterthought, because a printed WiFi code contains your literal password in a form that anyone who points a camera at it, not just your intended guests, can read back out or reuse. For a home network shared with a handful of trusted visitors, that's rarely a meaningful risk. For a business - a cafe, an office, a retail store - it's worth setting up a separate guest network, isolated from internal devices, point-of-sale systems, and shared drives, before handing this code out to every customer who walks in; that way a compromised or widely-shared guest password never puts anything more sensitive at risk.
Finally, remember that the credentials are baked permanently into whatever you print - if the password or router ever changes, whether because of a routine security rotation or a new router entirely, every old printed code stops working immediately and silently, with no visible sign of the failure until a guest tries and fails to connect. Building a password change into your routine for updating printed signage, the same way you'd update a printed phone number, avoids the awkward moment of watching a guest's connection attempt fail on a code you forgot was already out of date.
One more field worth understanding: a "Hidden Network" option, which corresponds to networks that don't broadcast their name publicly and normally require a device to already know the exact SSID before it can even attempt to connect. Marking this correctly when generating the code tells the joining phone to actively search for a network it wouldn't otherwise see listed, rather than simply selecting one from a visible list - skip this setting for a hidden network and the join attempt can fail even with a perfectly correct name and password.