JFDI Blog

Category: QR codes

  • Why your free QR code stopped working, and how to make one that won’t

    If a QR code that used to work now shows an error, an advert or a “subscription expired” page, it’s almost certainly a dynamic code. Dynamic codes don’t contain your link: they contain a short link to the QR company’s server, which forwards people to you, for as long as the company keeps doing it. A static code contains your link itself and keeps working forever. The JFDI QR code maker only makes static codes.

    Make a QR code that never expires

    Static and dynamic codes

    Static codeDynamic code
    What’s inside the codeYour actual link, Wi-Fi details or textA short link to the QR company’s server
    Works if the company closes or you stop payingYes, foreverNo
    Can be tracked (how many scans, where, when)NoYes
    Can show adverts or a landing page firstNoYes
    Can change the destination after printingNoYes

    Dynamic codes are a real product with real uses, such as campaign tracking. The problem is that many sites offering “free QR codes” make dynamic ones by default, without making the catch clear.

    What QR companies say themselves

    You don’t have to take our word for it. One vendor, Uniqode, writes that dynamic codes “can expire when a subscription lapses, a monthly scan limit is reached”, and that free dynamic codes “expire when the free trial ends or when a monthly scan limit is reached” (Uniqode). Another, QRStuff, says that when a paid subscription expires, “a 50 scans/month limit is automatically applied to each code” (QRStuff).

    The printed code looks exactly the same either way. You only find out when a customer tells you the code on your menu, poster or packaging doesn’t work.

    How to tell which kind you have

    Point your phone’s camera at the code and look at the link it shows before you open it:

    • Your own website’s address, such as yourcafe.co.uk/menu: it’s static. It will work as long as that page exists.
    • Someone else’s short address, often a QR company’s domain or an unfamiliar short link: it’s dynamic, and it depends on that company.

    How to fix a dead code

    You can’t revive a dynamic code without paying the company that controls its redirect. Your options:

    1. Pay to reactivate it, if reprinting would cost more.
    2. Replace it with a static code pointing straight at your page, and reprint.
    3. Cover it with a sticker of a new static code, as a quick fix for menus and posters.

    Making a code that won’t expire

    1. Open the QR code maker and choose what the code opens: a link, Wi-Fi, a contact card, an email, a phone call or a text message.
    2. Enter the details. The code updates as you type.
    3. Style it if you like, with colours, rounded dots and a logo. The notes under the preview warn you about anything that could stop it scanning.
    4. Download a PNG, SVG or PDF. Use SVG or PDF for print.
    5. Test it with two or three phones before you print lots.

    There’s no sign-up, no watermark and no limit, and the codes are yours to use commercially. Because the code holds only what you typed, nobody, including us, can see when or where it’s scanned.

    The one thing to plan for

    A static code can’t be changed after it’s printed. If the destination might change, such as a menu, a price list or an event page, point the code at a page on your own website that you can update, such as yourcafe.co.uk/menu, rather than at a PDF file whose address may change. You get the flexibility of a dynamic code without depending on anyone else.

    Related

  • How to make a Wi-Fi QR code

    To make a Wi-Fi QR code, enter your network name, password and security type into a QR code maker that has a Wi-Fi option, then print the code. In the JFDI QR code maker, choose Wi-Fi, fill in the three boxes and download. Guests point their phone’s camera at it and tap to join. iPhones running iOS 11 or later and Android phones running Android 10 or later can join straight from the camera app.

    Make a Wi-Fi QR code

    Step by step

    1. Open the QR code maker and choose Wi-Fi.
    2. Network name: type it exactly as it appears in your phone’s Wi-Fi list. It’s case sensitive, so Cafe_Guest and cafe_guest are different networks.
    3. Password: type it exactly, including capitals, spaces and symbols.
    4. Security: WPA / WPA2 / WPA3 for almost every modern router. Choose WEP only for very old equipment, or None for an open network.
    5. Hidden network: tick this if your network doesn’t broadcast its name.
    6. Add a caption such as “Scan to join our Wi-Fi”, so people know what the code is for.
    7. Download a PNG to print at home, or SVG or PDF for a print shop. Test it with two different phones before laminating.

    Special characters in the name or password, such as ;, : or ", are handled for you; the QR format needs them escaped, which trips up some generators.

    What’s inside the code

    A Wi-Fi QR code is a short line of text in a standard format that phones understand:

    WIFI:T:WPA;S:Cafe_Guest;P:coffee-and-cake;;

    T is the security type, S the network name and P the password. When a phone reads it, it offers to join that network with that password.

    Security: the password is readable

    Anyone who scans the code can see the password, and any QR reader app will display it as text. So:

    • Use a guest network. Most routers can run a separate guest network that has internet access but can’t see your computers, printers or smart devices. Put the guest network in the code, never your main one.
    • Only display it where you’d show the password anyway, such as inside your café, office reception or holiday let.
    • Change the guest password from time to time, and print a new code when you do.

    The JFDI QR code maker builds the code in your browser, so your Wi-Fi password is never sent to us or anyone else. That isn’t true of every generator: some send what you type to a server to make the image.

    Printing tips

    • Size: a Wi-Fi code holds a little more than a short link, so print it at least 3 cm wide. At a distance, a good rule is that the code should be at least a tenth of the scanning distance; see how small a QR code can be printed.
    • Contrast: dark code on a white or light background.
    • Leave the margin clear: don’t let text or a frame run into the blank border.
    • Put the network name and password underneath in text too, for laptops and older phones.

    Troubleshooting

    The phone sees the code but won’t connect

    Check the network name and password character by character, including capitals and spaces, and that the security type matches your router (almost always WPA). If you changed the password, the old code no longer works.

    Older phones don’t react

    Phones older than iOS 11 or Android 10 may need a QR scanner app. Print the network name and password under the code for them.

    Related

  • How to make a QR code for a menu or table

    To make a QR code for a menu, put your menu on a page of your own website, make a static QR code that links to that page, and print it on table cards with a short caption such as “Scan for the menu”. When the menu changes, update the page, not the code. The JFDI QR code maker makes static codes free, with no sign-up and no expiry.

    Make a menu QR code

    Step 1: give the menu a permanent address

    The most common mistake is pointing the code at something that will move:

    • A PDF file, which often gets a new address when you upload a new version.
    • A QR company’s short link, which can stop working when a free trial ends. See why free QR codes stop working.
    • A delivery app’s listing, which you don’t control.

    Instead, use an address you own and will keep, such as yourcafe.co.uk/menu. If you change the menu, change that page, or redirect it to the new PDF. The printed codes keep working.

    No website? Most website builders, and many booking and social platforms, give you a page you can update. Use the shortest address you can: short links make simpler codes that scan more easily.

    Step 2: make the code

    1. Open the QR code maker and choose Link.
    2. Paste your menu page’s address.
    3. Choose colours that match your brand, keeping the code dark and the background light. The notes under the preview warn you if the contrast is too low.
    4. Add your logo if you like, using Add a logo. Error correction switches to its highest level automatically so the code still scans with the logo covering part of it.
    5. Add a caption: “Scan for the menu”, “Menu and allergens” or “Order from your table”.
    6. Download an SVG or PDF for your printer, or a 2,048-pixel PNG for printing at home.

    Step 3: design the table card

    • Size: at least 3 cm wide for a code read from across a table; 4 cm is comfortable.
    • Say what it does in words next to the code, and add the web address underneath for people who prefer to type it.
    • Offer a printed menu on request. Not everyone has a phone, a signal or good eyesight, and a menu should be accessible to all your customers.
    • Use matt card. Glossy lamination reflects overhead lights and makes codes hard to scan.
    • Put the code where a phone can see it flat, not on a curved surface.

    Step 4: test it

    Scan the printed card with two or three different phones, at the table, in your restaurant’s actual lighting. Check the page loads quickly on mobile data, not just your Wi-Fi: a large PDF menu can take a long time to open on a weak signal, so a web page is better.

    Can I see how many people scan it?

    Not from the code itself: a static code just contains your link, so scans can’t be tracked by us or anyone else. If you want numbers, look at the visits to your menu page in your website’s statistics. That counts real visits without involving a QR company.

    Bonus: Wi-Fi codes for the same table card

    Many cafés put a second code on the card for guest Wi-Fi. See how to make a Wi-Fi QR code, and use a guest network, never your main one.

    Related

  • How small can a QR code be printed?

    A QR code with a short link can be printed as small as about 2 cm (0.8 in) wide, including its blank border, if it’s read from close up. Two things push the size up: how much the code holds, because more data means more, smaller squares, and how far away people scan it from. A good rule is that a code should be at least a tenth of the scanning distance: a poster read from 2 metres needs a code at least 20 cm wide.

    Make a QR code

    Why content changes the size

    A QR code is a grid of black and white squares (called modules). The more you put in it, the more squares it needs: the smallest code, version 1, is 21 × 21 squares, and each version up adds 4 more per side, up to version 40 at 177 × 177. Phones need each square to be big enough to see, so a denser code needs printing larger to keep its squares the same size.

    I ran some typical contents through the QR encoder the JFDI QR code maker uses, at its two most common error-correction levels:

    What the code holdsCharactersSquares across (Medium)Squares across (Highest, for logos)
    Short link: https://jfdi.pro/blog/menu212529
    Typical page link543341
    Wi-Fi network and password433337
    Long link with tracking parameters1124557
    Contact card (name, company, phone, email, website)1695369

    The long tracking link needs almost twice as many squares across as the short link, and with a logo it needs more than twice.

    Minimum sizes for close-up scanning

    Working from the 2 cm guideline for a short link, each square is about 0.6 mm. Keeping squares that size, and adding the standard blank border of 4 squares on each side, gives these minimum widths for codes read from close up (a table card, a business card, a product label):

    What the code holdsMinimum width (Medium)With a logo (Highest)
    Short link2.0 cm2.2 cm
    Typical page link or Wi-Fi2.5 cm3.0 cm
    Long link with tracking3.2 cm3.9 cm
    Contact card3.7 cm4.7 cm

    These are minimums for good conditions: sharp printing, a dark code on a light background, and a modern phone. Add a margin of safety for anything that matters, and test with an older phone.

    Minimum sizes for scanning from a distance

    For posters, shop windows and signs, distance matters more than content. Use the 10:1 rule as a starting point:

    Scanning distanceMinimum code width
    30 cm (in your hand)3 cm
    1 m (a poster on a wall)10 cm
    2 m (across a room)20 cm
    5 m (a shop window from the pavement)50 cm

    Dense codes need more than this; short links can manage a little less.

    How to make a code smaller

    • Shorten the link. Link to yoursite.com/menu, not a long page address with tracking parameters. This is the biggest win. (Avoid third-party link shorteners for print: if the service closes, the code dies. See why free QR codes stop working.)
    • Put fewer fields in a contact card. A name, phone and email are often enough.
    • Leave out the logo, or keep it small. A logo hides part of the code, so it needs the highest error correction, which adds squares.
    • Use square dots. Rounded and dot styles look nice but leave less margin for error at small sizes.

    The maker’s notes under the preview show the code’s version, its squares across and its error correction, and warn when a code holds enough data that it needs printing at least 4 cm wide.

    Printing checklist

    1. Download SVG or PDF for print, so the edges stay sharp at any size.
    2. Keep the blank border (4 squares is the standard; never less than 2).
    3. Dark on light, with contrast of at least 4:1, on a matt surface.
    4. Don’t print on curves or creases.
    5. Test the printed proof with two or three phones, from the real distance.

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