The Pinterest Conversions API on Shopify, explained

By the HonestTag team · Published October 30, 2026

The Pinterest tag runs in the shopper's browser. The Conversions API runs on a server. Pinterest wants both.

What the tag sees, and what the server sees

Pinterest compares the two methods side by side (Pinterest Developers):

	Pinterest tag	Conversions API
Where it runs	"JavaScript code snippets run in the user's browser when they visit your site."	"Your server sends conversion events directly to the Pinterest server."
What it can carry	It "Automatically collects page URL, referrer, device/browser info, IP address, timestamp, and Pinterest cookies (if present)," and you can add "order value, product ID, and user email/phone in hashed form."	It "Can ingest all the same event data as the tag, and more," such as hashed email, phone and external IDs, and order and product details.
What stops it	"Ad blockers and browser privacy settings can block or limit data collection."	"Not blocked by browsers or ad blockers."
What it needs	Cookies: the tag "relies on cookies for user identification and attribution." Pinterest adds: "User consent (GDPR/CCPA) may restrict what you can collect."	"Requires backend integration and data privacy compliance, such as hashing and user consent."

On Shopify the gap shows up as checkouts Pinterest never hears about: a shopper whose browser blocked the tag still placed a real order. A server that works from the store's orders does not depend on that browser.

Does your store already send it?

Maybe. Pinterest's own App Store listing for its Shopify app says the app helps you "Improve tracking and performance with the Pinterest Tag and API for Conversions" (Shopify App Store). Pinterest does not say on that listing which events the app sends each way, so check your own account rather than assume.

Pinterest grades the tag and Conversions API web events as separate ingestion sources. In Ads Manager, open Conversions, then Event Quality, and "Choose your Event source from the dropdown menu" (Pinterest Business Help). If a Conversions API web source is listed with recent events, something on your store already sends server events. The next question is whether it shares event IDs with your tag.

Counting each checkout once

Pinterest's rule: "Pass the event_id and event_name parameter in all the sources you use, making sure that the event_id is identical for each redundant event." Then "Pinterest retains the first event captured and removes duplicates within 48 hours" (Pinterest Developers). Its help center puts it plainly: "Event_id is the key we use to deduplicate events" (Pinterest Business Help).

A worked example, with made-up numbers. Say your store takes 100 online orders in a week, and the tag reports a checkout for 80 of them because blockers stopped it on the other 20. A server also sends a checkout for all 100.

• Same event name and event ID on both copies. Pinterest keeps the first copy of each of the 80 and drops the second. It counts 100 checkouts: the 80 the tag caught plus the 20 only the server sent. That is the coverage Pinterest is after.
• Different or missing event IDs. Pinterest cannot tell the copies apart. It counts 80 from the tag plus 100 from the server, 180 checkouts for 100 orders, and its cost per checkout looks better than it is.

Pinterest's Deduplication page in Ads Manager (Events Overview) shows your event ID coverage per event type, so you can see which case you are in. Then compare Pinterest's count with your orders; duplicate purchase events shows how to find every purchase source on a store.

What makes a server event match

Pinterest scores how well your events can be matched to its users. Its Event Quality Score counts "Customer Information (User Matching)," with "parameters like IP Address, Email and External ID," and "Event Insights (Product Metadata)," such as "Product ID, Order Value and Currency" (Pinterest Business Help). For a checkout on the web, Pinterest ranks these details:

• High: IP address with user agent, email, external ID, and on the order side page URL, product ID (when a catalog is present), order ID, order value and currency.
• Medium: click ID and phone number, and product price and quantity (when a catalog is present).

Three of Pinterest's rules catch stores out (Pinterest Developers):

• The click ID is epik. Pinterest calls it "a unique identifier that Pinterest uses to help track users across devices and sessions," "typically passed as a query parameter in your URLs, for example, after a click on a Pinterest ad." A server only has it if something on the store saved it when the shopper landed.
• The value leaves tax and shipping out. Pinterest's instruction for the order value is "Use pre-tax, pre-shipping total." See conversion value vs order total.
• Send it promptly. Pinterest asks for event data "in real time or with a maximum lag time of one hour."

What the Conversions API does not fix

• Consent. A server is not a way around a shopper's choice. Pinterest lists "data privacy compliance, such as hashing and user consent" as what the API requires. See cookie banners and conversions.
• Custom events that are never mapped. An event under your own name only counts in Pinterest once it is mapped to a standard event; "Otherwise, those events are untracked and cannot be used for reporting or optimization" (Pinterest Developers).
• Pinterest's count against your orders. More checkouts reaching Pinterest means more for Pinterest to credit. It is not proof that Pinterest drove more sales. Ad platform purchases vs Shopify orders covers how to compare the two fairly.
• The build. Pinterest's own comparison puts a direct integration at "2 to 4 weeks" with a developer, and a tag manager at "1 to 4 hours" for a "Marketer (IT or developer support recommended)"; for other partners, time "depends on the partner" (Pinterest Business Help). If you already run a tag manager, that route may be all you need.

How HonestTag handles this

• The free Mirror plan sends Pinterest no orders. Delivery comes with paid plans.
• On paid plans, each eligible online store order goes to Pinterest from HonestTag's server, built from Shopify's own order data and sent through the Pinterest Conversions API, so a blocked tag does not stop the event from being sent. Consent rules apply first, the same as for every destination.
• Your Pinterest app can stay. By default HonestTag sends its own custom events (every order, new customers, returning customers, and new customers whose first recorded ad click or ad-tagged link was for Pinterest), which do not add to your Pinterest checkout count. Pinterest's standard checkout goes only if you turn it on and confirm no Pinterest app or tag sends checkout for the store.
• Event IDs from the order. Each event HonestTag sends gets its own ID derived from the order, and the same ID on every retry, so a retry never adds a second purchase in Pinterest.
• The details Pinterest ranks, from the order. Of the ones Pinterest ranks High: the hashed email, a hashed HonestTag visitor ID as the external ID, the IP address and user agent Shopify recorded, the page URL, the product IDs, the order ID, the currency, and the order value without tax and shipping. Of the Medium ones: the hashed phone when its country is known, the epik click ID when HonestTag's pixel saw it on a Pinterest ad link, and each product's unit price and quantity. Pinterest needs an email, or the IP address and user agent together, so an order with neither is not sent.
• Proof per order. Each order's page in HonestTag shows whether Pinterest processed it. A failed delivery is retried, and you get an alert if it cannot get through.

What it does not do: HonestTag sends Pinterest no refunds, and it does not map its custom events to a standard event for you, so with the checkout switch off Pinterest's own reports show nothing from HonestTag. The full list of what is sent is on Connect Pinterest and server-side delivery.

Frequently asked questions