GET STARTED
Install the tracker
Add the Attrifast snippet to your site — one script tag, ~2.4 KB over the wire, no cookies by default — and see your first pageview, usually within a minute.
Attrifast tracks your site with a single script tag. The tracker is about 5 KB (~2.4 KB over the wire), uses no cookies by default (it keeps a first-party identifier in localStorage), and skips known bots automatically.
Event collection requires an active subscription or trial — start the 7-day free trial during onboarding (no charge today, cancel anytime). The Pro plan includes 100,000 events per month; pageviews and custom events count toward the quota, engagement heartbeats don't.
Add the snippet
Paste this in the <head> of your site, replacing the tracking ID with the one shown in your onboarding or Dashboard → Settings:
<script defer data-tracking-id="YOUR_TRACKING_ID" src="https://api.attrifast.com/af.js"></script>
Platform notes:
- Shopify — skip the snippet entirely: connect your store and the tracker is injected automatically.
- WordPress — paste the same snippet via the WPCode plugin or your theme's header; the WordPress guide walks through both routes.
- Single-page apps — route changes are tracked automatically; no extra setup for Next.js, React, Vue, or SvelteKit routers.
Events are only accepted from your website's registered domain — the one you entered when adding the site — including its subdomains (Shopify domains are added automatically on connect). If you serve the same site from a different domain, contact us and we'll add it to your allow-list.
Cross-subdomain tracking
By default the visitor ID lives in localStorage, which browsers scope per subdomain — a visitor who reads your blog on example.com and signs up on app.example.com would count as two visitors, breaking attribution across the boundary. To share one identity across all subdomains, opt in:
<script defer data-tracking-id="YOUR_TRACKING_ID" data-cross-subdomain="true" src="https://api.attrifast.com/af.js"></script>
With this flag the tracker keeps the visitor ID in a first-party cookie on your root domain instead (this is the one case where Attrifast sets a cookie — a random ID, no personal data). Install the same snippet on every subdomain; an existing visitor's ID is migrated to the cookie, not reset. Events from subdomains of your registered domain are accepted automatically.
One honest caveat: Safari caps script-set cookies at about 7 days, so cross-subdomain identity for returning Safari visitors can reset weekly — an inherent limit of client-set cookies that affects every analytics tool using them.
Verify it works
Open your site in a normal browser tab, then either:
- use Verify installation in onboarding — it flips to "Script verified! Events are being received." once the first pageview lands, or
- check your dashboard: the visit usually appears within a minute.
In DevTools you should see af.js load and a request to /api/collect.
What gets tracked
- Pageviews — automatic, including SPA route changes.
- Sessions and channels — every session is classified from its referrer and UTM parameters into a channel: Organic Search, Paid Search, Social, Paid Social, Email, AI, Referral, Affiliate, Display, or Direct. AI visits are additionally tagged with the engine (ChatGPT, Perplexity, Claude, Gemini, and more).
- Engagement — time-engaged heartbeats, so you get real dwell time instead of bounce guesses.
- UTM parameters — captured on landing and used for channel and campaign attribution.
Custom events
Track anything beyond pageviews with the global API:
window.attrifast.track('signup', { plan: 'pro' });
See custom events for the full API, and turn event names into goals to measure conversion rate per event.