Page views and attribution

The web SDK records which pages visitors see and which campaign or ad brought them to your site. Combined with your Stripe payments, this tells you the trials, conversions, revenue and refunds each campaign, ad set and ad produced.

Page views

The SDK records a $pageview event when the page loads and after every client-side navigation that changes the path, through history.pushState, history.replaceState or the back and forward buttons. Changes to the hash do not count, and a navigation that only changes the query string is not a new page view.

This covers single-page apps without any router code: Next.js (App Router and Pages Router), React Router, TanStack Router, Vue Router, SvelteKit, and any router built on the History API. A router that keeps the route in the hash, such as Vue Router's hash mode or React Router's createHashRouter, records only the first page view, and the hash is not recorded; call page() with the route's name on its route changes.

Every event carries the page's origin, path and title, the referrer's origin and path, and the screen and viewport size. The query string is not recorded, except for the campaign parameters below.

To record page views yourself, turn the automatic ones off and call page():

const voidhash = createVoidhashClient({
  analytics: { capturePageViews: false },
  publishableKey: "vh_pk_…",
});

await voidhash.page("Pricing", { experiment: "annual-first" });

Campaign attribution is recorded either way.

page() sends the same $pageview event the SDK records automatically. If your app calls page() on every route change, set capturePageViews: false, or every navigation is counted twice.

Create one client per project on a page. Two clients for the same project each record their own page views, so every page would be counted twice.

Keep pages out

To keep pages out of page views and out of every event's context, for example because their address carries personal data, return null for them from analytics.sanitizeUrl. It can also rewrite an address, for example to replace a token in an invitation link. See Keep private pages out of analytics.

Sessions

Every event carries a session id. A session ends after 30 minutes without events, the same as on iOS, Android and React Native. All tabs of your site share the session, and reset() starts a new one.

Campaign attribution

A visit whose URL has any of these parameters is a campaign touch:

The SDK writes each touch to the visitor's person profile:

• The first touch is kept forever, as the $initial_… traits.
• Every new touch replaces the $latest_… traits.

For example, $initial_ad_campaign_id is the campaign of the visitor's first ad click and $latest_utm_source the source of their most recent campaign visit. The page view of the touch carries the same values as $utm_source, $ad_campaign_id and so on.

The SDK reads the campaign from the page's address when it initializes and after each client-side navigation. If your app removes the campaign parameters from the address, for example to tidy the URL, initialize the SDK first. A page that analytics.sanitizeUrl keeps out records no campaign; for an address it rewrites, the SDK reads the campaign and the landing path from the rewritten one.

Reloading the page or navigating within your site with the same campaign parameters does not count as a new touch. Each touch writes every trait, with null for the values it does not have, so the first-touch and latest-touch traits always describe a single visit and never mix values from two. The page view of a touch carries only the values it has.

When a visitor signs in, identify() links their anonymous profile, including its campaign traits, to the user.

Voidhash also keeps each touch's campaign values and time, so Ads reports can credit a signup to the visitor's last touch before it, within your project's attribution window. See Ad measurement.

Meta ads

Add these URL parameters to your ads. In Ads Manager, set them under Tracking > URL parameters at the ad level:

utm_source=facebook&utm_medium=paid_social&utm_campaign={{campaign.name}}&utm_term={{adset.name}}&utm_content={{ad.name}}&campaign_id={{campaign.id}}&adset_id={{adset.id}}&ad_id={{ad.id}}

Meta fills in the {{…}} values when the ad is clicked, and adds fbclid itself. The ids give exact attribution to a campaign, ad set and ad even after you rename them.

If your ads already have URL parameters of their own, you can keep them as long as one of them carries {{ad.id}}, such as utm_id={{ad.id}}. With your Meta ad account connected, Voidhash finds the ad set and campaign of that ID among the synced ads.

The SDK also stores Meta's click and browser ids on the person, as $fbc and $fbp:

• $fbc comes from the Meta pixel's _fbc cookie when it is present and less than 90 days old. Otherwise the SDK builds it from the fbclid of the visit, in Meta's fb.1.<timestamp>.<fbclid> format.
• $fbp comes from the Meta pixel's _fbp cookie, when your site uses the pixel.

The SDK reads these cookies but never sets any.

Attribute Stripe payments

To credit revenue, renewals, and refunds to the campaign that brought the visitor, pass the visitor's Voidhash ID to Stripe when your server creates the Checkout Session or customer. See Stripe revenue.

Bots and crawlers

Events from well-known crawlers, link-preview fetchers, uptime monitors and headless browsers are discarded when they arrive, so they do not count as page views, sessions or campaign touches.