What is a QR code?

A quick response (QR) code is a type of two-dimensional barcode that stores data in a square grid of black and white modules. It can contain various types of data, such as URLs, text, contact information, app store links, or deep links to specific screens within a mobile app.

When scanned with a smartphone camera or QR code reader, a QR code is decoded and the embedded data is retrieved. The scan triggers an action based on the data type, such as opening a website, launching an app, or navigating to a specific in-app location. QR codes include error correction, allowing them to work even when partially obscured or damaged.

There are two types of QR codes:

• Static QR codes contain fixed data that cannot be changed after creation.
• Dynamic QR codes contain a redirect URL that can be updated, supporting tracking, A/B testing, and routing logic such as device- or location-based redirection.

QR codes serve four main functions in mobile marketing:

Offline-to-online (O2O) and cross-platform tracking

Codes placed on packaging, print ads,  in-store signage or on connected (TV) ads can be tracked when scanned. Metadata such as timestamp and device type can be logged, linking offline interactions to app activity.

App install and engagement

QR codes give users a fast way to install an app or open in-app content. They remove friction by linking directly to the app store, onboarding flows, or specific features, without requiring search or manual input.

Attribution and ROI measurement

When integrated with mobile measurement partners (MMPs) like Adjust, dynamic QR codes can include campaign parameters that enable attribution of scans to installs, sessions, or in-app events.

Contextual routing

Dynamic QR codes can adjust the destination based on device type, app install state, or location. This supports deep linking, deferred deep linking, or platform-specific routing without generating multiple codes.

QR codes are used across app categories to support user acquisition, engagement, and retention. Below are examples from three key app categories:

Gaming

Codes printed on physical items or displayed digitally can unlock in-game bonuses when scanned. During livestreams or events, developers display QR codes that direct viewers to app downloads or time-limited offers. Games may also support shareable referral codes, where scanning installs the app and grants rewards to both users.

Subscription apps

QR codes simplify trial activation and re-engagement. Ads may include codes that open a landing page or app store link with a free trial applied. Codes on physical products can prompt sign-up, while those sent via email or mail can apply discounts or reopen access when scanned.

Retail and e-commerce

Codes on packaging or displays link in-store interactions to app actions, such as product lookup or app installs. Retailers also use QR codes in loyalty campaigns to re-engage users with targeted promotions or to drive app-exclusive offers through media placements.

With Adjust, you can measure how QR code campaigns perform across channels. Each scan is logged as a campaign interaction and linked to installs, in-app events, and revenue, providing insight into user behavior from scan to app engagement.

With Adjust’s deep linking solution, TrueLink, QR codes can route users to the appropriate destination based on context such as device type, location, or install state. This ensures users reach the right app store page or in-app content seamlessly and without extra steps.

All scan data is processed through Adjust’s attribution, giving marketers a unified view of performance and helping connect offline and multi-platform interactions with app engagement.

Request a demo now and learn how Adjust can help you track QR codes across the entire user journey.