QR codes, static and dynamic

A static QR code encodes your content directly. The URL, the text, the Wi-Fi credentials - whatever you put in - live inside the black-and-white pattern itself. When someone scans it, their phone reads the pattern and acts on it. No server sits in the middle. That’s the source of its best property and its one limit: because the content is the code, a static QR is yours forever and can never expire, but it also can’t be changed after you’ve printed it. To point somewhere new, you make a new code.

A dynamic QR code encodes a short Kilo link instead of your final destination. The pattern points at something like qr2r.com/aA3k9, and that link forwards to wherever you’ve set it. The pattern on the poster never changes, but the place it leads can - as often as you like, from the dashboard, without reprinting. That’s the trade: a dynamic code depends on Kilo staying up and the link staying live, and in return, it’s editable and it reports every scan.

Kilo makes dynamic links never-404 on purpose, precisely so that dependency is safe: a paused or over-quota link resolves to a branded page that explains what happened, rather than a browser error. But if you want a code that answers to no one and outlives everything, a static QR is the honest choice - and it’s free forever.

The Kilo QR designer runs entirely in your browser. Your content doesn’t leave the page until you download the result - the design is rendered on your own machine. You can encode many kinds of content: a web link, plain text, a vCard contact, Wi-Fi credentials, and more.

From there, it’s a design tool. You can change the module shapes, recolor with solid or gradient fills, drop a logo into the middle, and add a frame or a caption. PNG and SVG exports are free; animated GIF and MP4 exports - for codes that need to move on a screen - are part of every paid Kilo QR plan. There’s no watermark on the free exports and no signup wall in front of the designer.

A QR code can look sharp in design software and still fail on a wall, because the things that make it pretty are the same things that make it hard to decode: low contrast between the pattern and its background, a logo that covers too much of the data area, or intricate module shapes laid over a busy photo. A code has to survive bad light, a phone held at an angle, and a cheap camera.

That’s what the scan-safety score is for. As you design, Kilo decodes your work-in-progress on the spot and tells you whether it will read in the wild. When something is risky - the contrast is too low, the logo is nibbling at the data - it says so, and each warning comes with a one-click fix. The rule of the house is that beauty and decodability ship together: the designer never lets you make a gorgeous code without telling you whether it scans.

Before you commit to a run, test the worst case. Export the code and print a single copy at the smallest size it will ever appear - for most uses, that’s around credit-card size, roughly 2 by 2 centimeters. Then scan it with an ordinary phone, from a normal reading distance, in unremarkable light. If it reads there, it will read on a larger poster too. The reverse is not true: a code that scans at A2 poster size can easily fail on a business card.

A few habits that pay off: keep a clear margin of quiet space around the pattern so the camera can find its edges, prefer a dark pattern on a light background over the reverse, and keep any logo well inside the safe coverage the score allows. For a dynamic code, decide where the link points before you print - and remember you can always change it later without touching the paper.

With a QR code in hand, the next thing worth understanding is the link sitting behind it: how it’s created, paused, archived, and how anyone can check where it leads before they trust it.