What is First-Touch Attribution? Complete Guide for 2026

What First-Touch Attribution Is

First-touch attribution is a single-touch attribution model that credits a conversion entirely to the first marketing interaction a user had. Every later touch, the search ad, the retargeting email, the final install click, gets nothing.

It is the mirror image of last-touch attribution. Last touch asks which channel closed the conversion. First touch asks which channel started the journey.

How It Works

To use first touch, you need a record of each user's earliest known interaction. On the web this is usually captured on the first page view: the referrer, UTM parameters, and any ad click ID in the URL, stored in a first-party cookie or local storage. When the user later converts, the conversion is credited to that stored first touch.

For example:

1. A user taps a creator's Instagram story and lands on your website. First touch: Instagram, creator campaign.
2. Three days later they search your brand on Google and click a search ad.
3. They install the app from the Play Store link on your site.

First touch credits Instagram. Last touch credits the Google search ad. A multi-touch model would share credit between them.

Where First Touch Helps

Finding the channels that start demand. Video, creators, podcasts, content and broad social campaigns often introduce users who convert later through search or direct visits. Last touch hides that work, and first touch brings it back into view.

Judging top-of-funnel spend. If brand search installs rise every time a video campaign runs, first-touch reports make the link visible in a way last-touch reports do not.

Web-heavy journeys. Products where users research on the web before installing, such as fintech, health or high-ticket shopping apps, often have long gaps between the first visit and the install. First-touch UTMs on the web capture where those journeys began.

Where It Misleads

• It ignores what closed the deal. A channel that brings curious visitors who never install still looks good under first touch if a few of them convert later through other channels.
• It depends on memory. Cookies expire, browsers clear storage, and users switch devices. When the real first touch is lost, the next recorded touch takes its place without any sign that it was not first.
• It does not match networks. Ad networks optimize and bill on their own models, usually last touch or their own self-attribution. First-touch numbers will not reconcile with network dashboards.

First Touch in Mobile Measurement

In app install attribution, last touch is the standard because each install needs one closing source for billing and postbacks. First-touch data is more common on the web side of the journey and in multi-touch views.

Linkrunner's Web SDK, in beta, captures first-touch and last-touch UTMs, ad click IDs, and traffic classes for AI assistants, search, social and referral, so a team can see where a web journey began as well as how it ended. For installs, Linkrunner credits one source with last-touch rules, and offers multi-touch views per project on request, with a data-driven model, assists and journeys. See web-to-app and mobile attribution.

Using First Touch Well

• Read first touch next to last touch, never alone. Channels that rank high on first touch but low on last touch are likely starting journeys that others finish.
• Keep the same UTM conventions everywhere, so first-touch sources group cleanly.
• Treat it as a planning view for budget mix, and use incrementality testing when you need proof that a channel causes installs.