--- title: "QR Code Guide: How to Make, Size and Scan One (2026)" description: "Make a QR code that scans: pick the right size and error correction, keep the quiet zone clear, and store the QR images that hold private data in a vault." url: https://www.vaultforyou.app/en-gb/blog/qr-code-guide lang: en-gb published: 2026-10-29 updated: 2026-10-29 author: "VaultForYou Editorial Team" publisher: VaultForYou --- # How to make a QR code, choose its size, and keep what it contains private > A QR code is a picture of data, and the data is readable by anyone who scans it. Here is how to make one that scans reliably, what size to print it, and how to keep a copy of the private ones out of your camera roll. Published 2026-10-29 - Updated 2026-10-29 - By VaultForYou Editorial Team ## Quick answer To make a QR code that scans, use dark modules on a light background, keep a quiet zone of four modules around it, print it at least 2 cm wide, and raise error correction only if you add a logo. Anyone who scans a code can read its data, so keep codes with private information in a VaultForYou vault. - **Colours:** Dark modules on a light background. Inverted codes often fail to scan. - **Quiet zone:** Keep a blank margin of four modules around the code. - **Minimum size:** At least 2 cm wide for a card, larger for a poster. - **Private codes:** Store the image in a vault, outside your Photos library. A QR code is a square of black and white modules that stores data. Phone cameras read it and act on it: open a link, join a network, save a contact. It is simple to make and easy to get wrong, usually in ways that only show up when someone tries to scan it. This guide covers how to make a QR code that scans reliably, the size and colour rules that matter, and how to keep the codes that carry private information from ending up somewhere public. ## What a QR code holds A QR code encodes text, usually a link, a short message, a contact, or a network record. The data is inside the image itself, so nothing needs to be sent to a server to read it. That is why QR codes work offline, and why anyone who scans one gets the data. It also means a QR code is not a picture you can share the way you share a photo. A photo of a face or a place is pixels. A QR code of a photo is only a link to where the photo is stored, so the photo is exposed to anyone who follows it. ## How to make one 1. **Choose the content.** A link, plain text, a Wi-Fi network, a phone number or a contact card. Each type has its own format, so pick the right one. 2. **Type the content exactly.** One wrong character in a link breaks the code, and you often will not notice until someone scans it. 3. **Pick the output.** Use SVG for print, since it stays sharp at any size. Use PNG for a phone or a screen. 4. **Test before you share.** Scan the code with two phones, from the distance people will actually use. ## Colour and contrast Dark modules on a light background scan most reliably. Inverted codes, with light modules on a dark background, often fail, because many scanners expect dark on light. If you want a coloured code, keep the contrast high and test it. Avoid printing on glossy or curved surfaces. Glare and curvature distort the modules, and that is a common cause of codes that fail to scan. ## Size and the quiet zone The quiet zone is the blank margin around the code. The standard calls for four modules of clear space on every side. Designers often crop it to fit a layout, and that breaks scanning more often than any other mistake. For size, make the code at least 2 cm wide for a table card, and larger for anything read from further away. As a rough guide, the code should be about one tenth of the scanning distance. A card read from 30 cm needs about 3 cm. A poster read from 2 m needs about 20 cm. ## Error correction and logos Error correction adds redundant data, so a damaged or partly covered code can still be read. The four levels recover roughly 7, 15, 25 and 30 percent of the code. Higher levels make the code denser, which means it needs more printed space to scan. Use the lowest level that works. Raise it only when you add a logo in the middle, or when the code will be exposed to wear. Error correction does not rescue a code printed too small, and it does not make a code with a blank quiet zone scan any better. ## QR code or barcode? A barcode stores data in one direction, in a row of lines, and usually holds a short number. A QR code stores data in two directions, in a square, and can hold text, links and much longer records. The practical result is that a QR code can carry far more data in the same space, and it can be read from any angle. ## Keep private codes out of your photos Many QR codes carry private information. A Wi-Fi card holds the network password. A contact card holds a phone number and an address. A link can open a private document. Anyone who scans the code reads all of it, and anyone who photographs it keeps it. Keep the image of a private code somewhere safer than your camera roll. VaultForYou stores photos and documents in a vault outside the Photos library, so the code does not appear in Photos, search or widgets. The vault opens only with a pattern you draw, and the lock screen shows no vault names, counts or previews. To share a private code, send it as an encrypted vault link you can revoke later, rather than as a plain image in a message. The recipient does not need an account, and you can stop access at any time. Our guide to [Wi-Fi QR codes for guests](/en-gb/blog/wifi-qr-code-for-guests) covers the network case in more detail, and [removing location from photos on iPhone](/en-gb/blog/remove-location-from-photos-iphone) explains how to strip location from a photo of a code before you share it. ## Bottom line A good QR code is dark on light, with a clear quiet zone, printed large enough for the distance it is read from, and tested before it goes out. Treat any code that holds private data as a password: keep its image in a vault and share it only through a link you can revoke. ## QR code FAQ ## Frequently asked questions ### How do I make a QR code? Choose the kind of data you want to encode, such as a link, plain text, a Wi-Fi network or a contact. Type the content exactly, generate the code and download it as SVG for print or PNG for screens. Scan the result with two different phones before you use it. ### What size should a QR code be? As a rough rule, the code should be about one tenth of the distance it is scanned from. A card read from 30 cm needs about 3 cm, and a poster read from 2 m needs about 20 cm. Print it larger rather than smaller, and always test the printed copy. ### What does the error correction level do? It adds redundant data so a damaged or partly covered code can still be read. The four levels recover roughly 7, 15, 25 and 30 percent of the code. Higher levels make the code denser and larger, so use the lowest level that works, and raise it only when you add a logo or expect wear. ### Why won't my QR code scan? The usual causes are an inverted colour scheme, a missing quiet zone, a code printed too small, low contrast, or too much data for the chosen size. Print the code at a larger size, keep the margin clear and test it again. ### Does a QR code expire? A QR code that holds text or contact details does not expire, because the data is inside the image. A QR code that points to a link works only as long as that link does. The code itself can be scanned as long as it is printed clearly. ### Should I keep QR codes that contain private information in my photos? No. A QR code can hold a Wi-Fi password, a contact card or a link to a private document, and anyone who scans it reads that data. Keep the image in a VaultForYou vault, which stores files outside the Photos library and opens only with a pattern you draw. Moving a file into a vault creates a copy, so delete the original from Photos and empty Recently Deleted afterwards. ## Keep reading - [Wi-Fi QR Code for Guests: How to Make One Safely (2026)](https://www.vaultforyou.app/en-gb/blog/wifi-qr-code-for-guests): Make a Wi-Fi QR code for guests in minutes. Use a guest network, understand what the code reveals, and keep photos of the printed card out of your camera roll. - [How to Remove Location From Photos on iPhone (2026)](https://www.vaultforyou.app/en-gb/blog/remove-location-from-photos-iphone): Remove location from photos on iPhone in a few taps: turn off Location in the share sheet, strip it from a photo with Adjust Location and stop Camera saving it. - [How to Hide Photos on iPhone: Hidden Album Guide (2026)](https://www.vaultforyou.app/en-gb/blog/hide-photos-on-iphone): Hide photos on iPhone in seconds, find your hidden photos in the Hidden album, and see who can still open them, what syncs to iCloud and when a vault is better. - [How to Lock Photos on iPhone: 4 Ways That Actually Work (2026)](https://www.vaultforyou.app/en-gb/blog/lock-photos-on-iphone): Lock photos on iPhone with the Hidden album, a Face ID lock on the Photos app, a locked note or an encrypted vault, and see who can still open each one. --- Our guides are written and fact-checked by the VaultForYou team against Apple's own documentation. We make VaultForYou, a private vault app for iPhone. Download on the App Store: https://apps.apple.com/app/vaultforyou/id0000000000