The browser pixel
Your ad platform’s own pixel sends events from the visitor’s browser. When Whence runs it instead, the browser and the server send each event with the same ID, and the platform counts it once. You then remove the platform’s own app or pixel code.
This is optional on Shopify, and needed on other platforms for purchases (see below). Whence can run the browser pixel of Meta, TikTok, Snapchat, Pinterest, Reddit and Microsoft Advertising. Google Ads, Taboola and Klaviyo are sent from the server only.
Turn it on for a pixel
Two places do the same thing:
- In the pixel’s form (Set up, then More options, or Details then Edit settings): check Whence also runs the Meta pixel in the browser (the name follows your platform).
- On the Conversions screen, open the folded card Browser pixel (optional). Each pixel you set up for these platforms has a checkbox. Checked, it reads Whence runs this pixel in the browser. Unchecked, Your own pixel or app runs in the browser.
For Pinterest, also fill in Pinterest tag ID (optional): Ads Manager > Conversions > Tag manager, the number of your tag. It is different from your ad account ID. Without it, Pinterest is left out of the browser code.
If no pixel is set up yet, the card says: “Set up Meta, TikTok, Snapchat, Pinterest, Reddit or Microsoft first.” If none has the browser pixel turned on, it says: “Turn on the browser pixel for at least one platform above to get the code.”
On Shopify: add the custom pixel
The Whence app already adds its own pixel to your store when you install it. That pixel reports the steps to Whence’s server, but Shopify runs it in a closed space where ad platform scripts cannot load. So the browser pixels go in a custom pixel that you paste once.
Step 1: Open Customer events
In Shopify admin, open Settings > Customer events > Add custom pixel, and name it “Whence”.
Step 2: Set the permission
Under Customer privacy, set Permission to “Required” and choose Marketing.
Step 3: Paste the code
On the Whence Conversions screen, open Browser pixel (optional), click Copy code under Custom pixel code, paste it in Shopify, then click Save and Connect.
Step 4: Remove the other pixels
Remove the other pixels for the same platforms (apps or theme code), or each event is counted twice. See Deduplication with native pixels.
The code contains only the public IDs of the pixels you gave Whence, never a key or token. It also lists the steps checked for each pixel. So it changes when you turn the browser pixel on or off, turn a pixel off, or change its steps: copy it again and replace the old code in Shopify.
On other platforms: add the tag
On WooCommerce, BigCommerce or your own site, the card gives a Tag to add to every page of your site, just before </body>. Page views are sent on their own. At each other step, your site calls the tracking function, for example:
window.whencePixels.track('add_to_cart', { value: 24, currency: 'USD',
items: [{ id: 'MUG-01', quantity: 1, price: 24, name: 'Ceramic mug' }] });The steps are view_content, add_to_cart, initiate_checkout, add_payment_info and purchase. For a purchase, also pass order_id.
On a store that is not on Shopify, Whence cannot yet tie an order to its visit from the server in a way nobody can fake. Purchases reach your ad platforms through the browser pixel only. With the tag on your site, product views, carts and checkouts also go out from the server.
What the browser pixel does not send
- Nothing loads or leaves without the visitor’s marketing consent. A consent withdrawn later stops the next events. On Shopify, consent comes from Shopify’s customer privacy settings. Elsewhere, from your consent tool (Google Consent Mode, Cookiebot, OneTrust) or from your banner through
whence.consent(). - The Pinterest tag has no product view, checkout started or payment info event: those steps go out from the server only.
- The Microsoft UET tag sends page loads itself, so Whence does not send them from the browser.
Related: The funnel Whence sends, Which cookie banner Whence reads.