QR Code Generator
Anything a scanner should receive, a link, some text, a phone number.
4 is the specified minimum.
- 18
- Characters
- M
- Correction level
- 320px
- Output size
Enter some text to encode.
The generator produces a QR code as a PNG you can download, encoding a URL, plain text, a Wi-Fi network or a contact card. The code is built in your browser and points directly at what you entered. There is no redirect through a tracking domain, which means it cannot expire or start charging.
How it works
A QR code is a grid of modules encoding bytes, plus Reed-Solomon error correction so a damaged code still reads. The version, from 1 to 40, sets the grid size and is chosen automatically from how much data you have and how much correction you asked for.
- Level L recovers about 7% damage, M about 15%, Q about 25% and H about 30%.
- Higher correction means more modules for the same data, so the pattern gets denser and needs to be printed larger.
- Wi-Fi codes use the WIFI:T:WPA;S:name;P:password;; format that phone cameras recognise natively.
- Contact codes use vCard 3.0, which both iOS and Android offer to add to contacts.
The quiet zone, the blank margin, is part of the specification, not decoration. Four modules of white space on every side is the minimum; a code cropped tight to its edge frequently fails to scan.
Examples
A short URL
Content
https://example.com
Correction
M
Result
Version 2 · 25 × 25 modules
Nineteen characters fits a small, sparse grid that scans reliably from a distance and prints legibly at 2 cm.
The same URL at level H
Content
https://example.com
Correction
H
Result
Version 3 · 29 × 29 modules
The correction data itself takes space, so the grid grows. That is the trade: more resilience, smaller modules at the same printed size.
A Wi-Fi network
SSID
CafeGuest
Security
WPA
Result
WIFI:T:WPA;S:CafeGuest;P:••••;;
Scanning it prompts the phone to join the network. The password is in the code in plain text, so anyone who photographs the sign has it.
Frequently asked questions
Will this QR code ever expire?
No. It encodes your content directly, so there is no service in the middle that can shut down or start charging. Many free generators produce a code pointing at their own redirect domain, which stops working the moment that service does. Check any code you did not make here.
Which error correction level should I use?
M for anything on a screen or a clean printed page. Go to Q or H only when the code will be printed small, on a curved surface, somewhere it will be scuffed, or with a logo covering part of it. Higher levels make the pattern denser, which is counterproductive at small sizes.
How small can I print a QR code?
About 2 cm square for a short URL at normal scanning distance, and the rule of thumb is that the code should be at least a tenth of the distance it is scanned from. Long content needs more modules and therefore a larger print for the same reliability.
Is the Wi-Fi password secure in a QR code?
No. It is stored as plain text and anyone who scans or photographs the code has it. That is fine for a guest network on a café table and wrong for your main network. Use a separate guest SSID.
Why does my code fail to scan?
Most often the quiet zone has been cropped away, or contrast is too low. Keep four modules of blank margin on every side, keep the pattern dark on a light background rather than the reverse, and avoid printing on a reflective surface.
Can I put a logo in the middle?
Yes, if you generate at level H and cover no more than roughly 20% of the area, dead centre. The error correction reconstructs what the logo hides. Test the result on more than one phone before printing a thousand of them.