Free QR code generator

How big should a QR code be?

Almost every QR code that “does not work” is simply too small for the distance it is scanned from, or printed so small that the individual squares blur together. Two numbers settle it.

The smallest square matters more than the total size

A QR code is a grid of modules. The more you encode, the more modules the code needs, and the smaller each one becomes at the same printed width. Keep every module at 0.4 mm or larger for offset and digital printing; ask for 0.6 mm or more on cardboard, textile, thermal receipt paper and anything printed on a curved surface.

So the cheapest way to make a code easier to scan is to shorten the data. example.com/x7 needs far fewer modules than a URL carrying three tracking parameters. Two more free wins: drop the https:// only if you must (most scanners need it for links), and note that a URL typed in capitals — EXAMPLE.COM/MENU — encodes more compactly than lower case, because upper case fits the alphanumeric mode. Domains are case insensitive, so it still works.

Colour and contrast

A scanner does not see colours, it sees light and dark. The rules that follow from that are short:

• Dark code on a light background. Inverted codes (light on dark) are read by many phones but rejected by plenty of older scanners, kiosks and access-control readers. If you must invert, test the exact devices that will be used.
• Aim for a contrast ratio of at least 4:1, treat 3:1 as the hard floor. The panel next to your code shows the live ratio. Pale pastel on white and dark grey on black both fail here.
• Red, orange and yellow read as “light” to many older infrared and red-laser scanners. Dark blue, dark green, deep purple, near-black and brown are safe choices for the modules.
• No photographs or gradients behind the code. A flat panel behind the modules costs you nothing and prevents a whole class of failures.
• Matte, not glossy. Glossy laminate and glass throw back the phone’s own light; varnish a window around the code instead.
• Keep the quiet zone. Four empty modules on all sides. Text, a border or a photo edge inside that margin makes the code hard to find, even though the data is intact.

Watch out for one more thing in print: ink spread. On absorbent stock the dark modules grow and swallow the light ones. If a supplier tells you the code came out “muddy”, print the modules slightly smaller rather than pushing the whole code up in size.

Logos and error correction

Every QR code carries redundant data, so it survives damage. That is what makes a logo in the middle possible, and it is also the budget you spend when you add one.

• Cover no more than about 15% of the area with your logo, and raise the level to Q or H when you do.
• Keep the three corner squares and the timing lines between them completely clear. They are how a scanner finds and aligns the code; no amount of error correction repairs those.
• Put the logo in the centre and leave a small padded gap around it, so the scanner does not read the edge of your artwork as a module.
• Error correction is a safety margin, not a feature to spend. A code that only just scans on your new phone will fail on a five-year-old one in a dim restaurant.

Print and test checklist

1. Scan the final artwork at final size, not the file on your monitor.
2. Test with at least two phones, one of them a few years old, and once in dim light.
3. Check the whole journey: does the page the code opens work on a phone, and does the Wi-Fi password still match?
4. Send vector files (SVG or EPS) to a printer. Ask them not to scale non-proportionally and not to apply a spot varnish over the code.
5. Tell people what they get. A caption such as “Menu” or “Free Wi-Fi” is worth more than any design trick.
6. Put the code where a phone can reach it: not above a shop window, not behind a counter, not on a moving vehicle.
7. Keep a text alternative nearby — a short URL, a phone number — for anyone who cannot or will not scan.

Which download do you need?

Click a format above the download button to see that exact file in the preview, then download it. PDF and EPS are documents rather than images, so browsers cannot show them inline — for those two the preview keeps showing the PNG while the download stays fully vector.

PNG

The safe default for screens, e-mail, slides and web pages. Sharp edges, no compression artefacts. Choose 2048 px or more if it will also be printed small.

PNG with a transparent background

Tick Transparent background under Shape & colour. For placing the code on a coloured or textured surface — keep that surface light and flat, or you lose the contrast you need.

JPG

Only when a system insists on JPG. It cannot store transparency and its compression softens the edges of the modules, which is exactly the detail a scanner needs.

WebP

The same picture as PNG at roughly a third of the file size, with transparency. Ideal for your own website; less welcome in print shops and older software.

SVG

Vector, infinitely scalable, editable in Illustrator, Inkscape, Figma and Affinity. The best choice for print and large formats. Your logo travels inside the file.

PDF

Vector too, and the file most print shops actually ask for. It keeps the caption as real text in Helvetica and embeds your logo, so one file is enough to hand over.

EPS

Vector for older print and packaging workflows that still specify EPS. The caption uses Helvetica; a bitmap logo cannot be stored in it, so send the SVG or PDF when your design has one.

The list of bitmap formats depends on your browser: this page asks it what it can encode and only offers what really works. AVIF appears once your browser can write it — today most cannot, and a browser that is asked anyway quietly returns a PNG inside a file named .avif. GIF, BMP and TIFF are not offered: no browser encodes them, and none of them would beat PNG for a QR code.

Frequently asked questions

Open source, and why that matters here

This whole site is a static page: one HTML file, one stylesheet and five small JavaScript files, with no dependencies and no build step. The QR encoder was written for this project and verified against an independent reference implementation across all 40 symbol versions and all four error correction levels.

You can read, audit, self-host, fork and re-use all of it:

github.com/spidfire/qr-code-free-org

Licence

The source code is licensed under the Apache License 2.0 — use it commercially, modify it, ship it inside your own product, as long as you keep the notice and the licence text. The page text and documentation are offered under the same licence. QR Code is a registered trademark of Denso Wave Incorporated, which is not affiliated with this project; the symbol format itself is standardised as ISO/IEC 18004 and free to use. The QR codes you generate carry no licence from us at all.