UTM QR code generator for offline events

A QR code on a flyer or a booth brings people to your site with no referrer: without tags, analytics records the visit as direct and mixes it with everyone who typed the address. UTM parameters in the link inside the code say where the visitor came from. The default convention:

• Placement in utm_content when you compare events with each other and placements within an event. Reports keep one source, and an event does not break into a dozen sources.
• Placement in utm_source when the same formats (flyers, badges, posters) repeat across many events and you compare the formats themselves.
• Normalisation. Values are lowercased, non-Latin letters transliterated and spaces replaced with underscores: GA4 is case-sensitive, so “Booth” and “booth” would become two rows. These are the same rules — and the same code — as in the UTM builder.
• Keep the medium. Pick one utm_medium value — offline, print or qr — and use it for every offline campaign.

Google Analytics 4. Go to Reports → Acquisition → Traffic acquisition. Switch the primary dimension to “Session source / medium” and find the rows with medium offline; add the secondary dimension “Session campaign” or “Session manual ad content” (that is where utm_content goes). In the default channel grouping these sessions land in Unassigned: GA4’s rules do not know an offline medium. If you want a separate row, create a custom channel group with the condition “medium exactly matches offline”.

Yandex Metrica. Reports → Standard reports → Sources → UTM tags. Expand utm_medium = offline, then utm_campaign (the event) and utm_content (the placements). Add your goals to the report to see conversions, not just visits, for each placement.

• Look at the period from the start of the event to 1–2 weeks after: people scan flyers at home too.
• Visits without conversions are a signal as well: many visits from the booth but no sign-ups point at the page, not the code.
• If your site drops query parameters on a redirect (http to https, or to a mobile version), the tags are lost — check by scanning the code.

The popular rule says the side of a QR code should be at least a tenth of the scanning distance. We checked where it comes from: a phone camera with a field of view of about 70° sees a strip about 1.4 × d wide at distance d, and a decoder needs 3–4 camera pixels per module. That gives a module of at least d/250:

• A tagged link is longer, so its code is denser than a bare URL’s. The d/10 rule fits a short link; the tool computes the minimum for each of your codes.
• A logo on top only with error correction H (30 %), centred and covering no more than a fifth of the code.
• Margin — 4 modules of light background; do not put the code against the edge of the sheet or a dark panel.
• Dark code on a light background, matte paper without glare; for posters and print shops use SVG — it stays sharp at any size.
• Test a proof of every code from the real distance with two or three phones before the print run.

1. Google Analytics Help: Default channel group — channel rules and Unassigned — support.google.com/analytics.
2. Yandex Metrica Help: UTM tags report — yandex.com/support/metrica.
3. ISO/IEC 18004:2015 — QR Code bar code symbology specification (error correction levels, 4-module quiet zone).
4. PKWARE. APPNOTE.TXT — .ZIP File Format Specification 6.3 (the archive format built in your browser).