URL shortener with QR code: why the short link makes a better code

Any shortener can hand you a QR code. The reason to care which one is that the length of the link decides how good the code is.

The module arithmetic

A QR code stores a fixed number of characters per version, and each version is a grid of a fixed size. Fewer characters means a lower version, which means fewer modules across the same printed square, which means each module is physically larger.

Larger modules are what survive a cheap printer, a curved surface, poor light and a phone held two metres away. This is the one place where the difference between a 10-character link and a 40-character one is visible to the naked eye.

Where to get the code

Every link has one at its own URL. The .qr suffix returns a PNG sized for screens; the .svg suffix returns vector output for print. Size and colours are query parameters, which means a campaign with two hundred links can fetch two hundred codes from a script rather than from a download button.

Images are cached at the edge for a day, so a code printed on fifty thousand flyers costs nothing to serve when they all get scanned in the same week.

Editable after printing

This is the part a static QR generator cannot do. Encoding a destination directly into a QR freezes it in ink. Encoding a short link instead means the destination can be edited afterwards and every printed copy follows.

That is worth spelling out because it is the entire reason to combine a shortener and a QR generator rather than using a standalone generator: the code stays valid while the thing behind it moves.

The trap is expiry. A QR pointing at an anonymous 30-day link is a dead QR a month later. Anything going to a printer needs a link that does not expire, bought before the file is sent.

Scans against clicks

A visit through the QR endpoint is recorded as a scan rather than a plain click. That single distinction is what makes print measurable: put a different link on each poster location and the report tells you which wall works.

Print checklist

1. 1

   Use the SVG

   A resized bitmap is where most unscannable codes come from.
2. 2

   Two centimetres minimum

   More for anything read from further than arm's length. Roughly one tenth of the scanning distance is a reasonable rule.
3. 3

   Keep the quiet zone

   Four modules of clear space on every side. Bleeding artwork into the code kills it.
4. 4

   Keep the contrast dark on light

   Inverted codes fail on a lot of scanners. Dark modules on a light ground is the safe choice.
5. 5

   Test the proof, not the screen

   Two different phones, on the actual printed piece, before the run.

Related: QR codes for print, QR code size and scan distance, and the QR product page.