Generating QR codes that actually scan
Most unscannable QR codes are either printed too small or encode a URL that is far too long.
QR codes are straightforward to generate and easy to make unusable. The two failure modes are almost always the same: the code is printed too small, or the data encoded is too long, which forces a dense pattern that phone cameras struggle to resolve.
Practical numbers: a printed QR code should be at least 2 by 2 centimetres for close scanning, and considerably larger for anything scanned from a distance. Shorten long URLs before encoding rather than after printing. Also set error correction to at least medium, which lets the code still scan when part of it is scuffed, covered or poorly printed. The generator is in ToolHub.
QR Code Generator: the facts that matter
| Data types | URL, plain text, WiFi credentials, contact card |
| Minimum print size | 2 by 2 cm for close scanning |
| Error correction | Medium or high for print |
| Best print format | SVG, which scales cleanly |
| Contrast | Dark code on a light background. Do not invert |
How to do it, step by step
- 1Shorten your URL first if it is long. Fewer characters means a less dense, more reliable code.
- 2Open the QR generator in ToolHub and enter your data.
- 3Set error correction to medium or high, especially for anything printed.
- 4Export as PNG or SVG. Use SVG for print, since it scales without blurring.
- 5Test by scanning the final printed or on-screen version with more than one phone.
Three things worth knowing
- Test with at least two different phones before printing a thousand copies.
- SVG for print, PNG for screen. A stretched PNG is the most common printing mistake.
- For anything customer-facing, a QR code should point at a page that works properly on a phone. CodeAiMan's mobile app and web team builds for that constraint first.
Common problems, solved
Where to run it
This tool is part of the ToolHub tool library, a library of over 1,000 browser-based tools covering PDF, image, video, audio, text and developer work. Everything runs in the browser and none of it needs an account.
ToolHub is built by codaiman.com, an AI-first software company in Ahmedabad. Related to this page: Mobile app development android, ios and cross-platform apps in react native and flutter.
QR Code Generator, in the browser: no install, no sign-up, no upload queue. Part of the ToolHub library from CodeAiMan.
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