WRITING

Measurements, not opinions

Measurements, failure modes and specifications — not recycled advice. Everything here comes from our own calibration data or from documented standards we can cite.

ORIGINAL RESEARCHIn preparation

We printed 400 QR codes at six sizes and scanned them with six phones

The calibration study behind our scanability engine. Twelve thousand codes generated across the parameter matrix, four independent decoders, 400 stratified samples printed on matte and glossy stock and scanned under three lighting conditions — including on a ₹8,000-class Android, because that is what a lot of people actually hold. Full dataset and methodology published.

Not published — the study has not run yet

What it will measure

Scan rate by printed sizeNot measured yet

Scan rate by phone and decoderNot measured yet

Matte against glossy stockNot measured yet

Three lighting conditionsNot measured yet

Scanability

Why won’t my QR code scan? Five causes, and which of them we can measure

Four of the five have an answer in the specification or in arithmetic you can repeat. The fifth is the one every tool gives you a number for, and it is the one nobody should.

22 Aug 2026 · 11 min readRead Print

How big should a QR code be? The arithmetic, and the part nobody can give you

Payload length sets the module count, the module count divides your print width, and the printer’s resolution decides whether a module prints cleanly. All three are arithmetic. The scan distance is the part that is not.

1 Nov 2026 · 3 min readRead Payments

What a UPI QR code contains, field by field — and the ones that break payments

A UPI QR code is a link that starts upi://pay, followed by a handful of fields. Most failed scans at a counter come from three of them being missing, malformed or wrongly encoded.

1 Nov 2026 · 3 min readRead Dynamic QR

What “expires” really means when a QR code stops working

The code never expires. The redirect behind it gets switched off. A plain-language account of how the category ended up here.

1 Nov 2026 · 3 min readRead Dynamic QR

Static or dynamic: a decision table, not a sales pitch

Six questions that settle it, including the two cases where a static code is genuinely the better engineering choice.

1 Nov 2026 · 3 min readRead Design

How much of a QR code can a logo cover?

Error correction gives you a damage budget. A logo spends it before the code is printed, and the budget is counted in codewords, not in area — which is why “up to 30%” is the wrong way to think about it.

1 Nov 2026 · 3 min readRead Design

Dot styles, rounded eyes and the modules you are quietly shrinking

A round dot inside a square module is 79% of the ink the square would have been. That is the first cost of a dot style, and it is arithmetic. The second is what styling does to the corner patterns a camera looks for first.

1 Nov 2026 · 3 min readRead Security

Quishing: how QR phishing works and what actually stops it

Sticker-over-sticker attacks, redirect chaining and homograph domains — plus why decoding before opening defeats all three.

1 Nov 2026 · 3 min readRead Scanability

CMYK conversion is why your code failed at the printer

A code designed on screen is in RGB; a press prints CMYK. The conversion moves colours — usually toward lower contrast — and a code that passed on screen can arrive under the line on paper.

1 Nov 2026 · 3 min readRead Security

Why we never store a raw IP address

Geo is derived at the edge and the address discarded before the event leaves the worker. What that costs us in analytics, and why it is worth it.

1 Nov 2026 · 3 min readRead Payments

UPI QR codes with a fixed amount: when to use one, and when it costs you payments

Putting the amount in the code saves the customer typing it and stops wrong amounts. It also means the code is wrong the day the price changes — and a payment code cannot be a dynamic redirect.

1 Nov 2026 · 3 min readRead Scanability

Error correction levels L, M, Q and H: what each costs, and when to raise it

A higher level lets a code survive more damage and makes it denser for the same data. Choosing it is a trade between those two, and the numbers for both are in the standard.

1 Nov 2026 · 3 min readRead Print

Curved, glossy, outdoors: where printed QR codes meet the real world

A bottle bends the code away from the camera, a laminate throws the light back at it, and a summer in a shop window takes the black out of it. Each has a cause you can reason about before printing.

1 Nov 2026 · 3 min readRead

Showing all 13 posts. Written in English first — non-English editions are written natively, never machine-translated.

Every article cites the standard it relies on, shows its arithmetic, or describes this site’s own code. None of them reports a measurement of ours until the print-and-scan study has run.

How we write here

Every factual claim is verified against a specification, a circular, or our own measurements — with the date it was checked. Nothing is machine-translated. Competitor comparisons carry the date we read their live pricing page, because it changes.

Every measurement reproducible from the published dataset
Specifications cited, with the clause and the date read
Competitor claims dated, because their pricing changes
No AI-written factual claims — drafting help is fine, verification is manual