The usual causes
The tag is installed twice
Once in the theme or site code, and once through a tag manager or a platform plugin. Each copy sends its own Purchase. This is by far the most common cause.
GA4 is configured twice
A hard-coded gtag('config') snippet and a GA4 tag inside Tag Manager, both pointed at the same Measurement ID.
No order ID to deduplicate on
The order ID is what lets a platform drop a repeat of the same order, from a refreshed thank-you page or from a server-side event reporting the same sale. Without it, duplicates cannot be removed. For Meta, the browser event and the Conversions API event also need the same event ID.
How to find the second install
Search the page source and the tag manager for the Pixel ID or Measurement ID. Two places means two installs. Keep one.
In the browser's Network panel, place a test order and count the purchase requests on the confirmation page. One order should be one request per platform.
What TagZ checks, and what it cannot
The scan flags the same once-per-page event (page_view, begin_checkout, purchase, sign-up, lead) sent more than once to the same account, for the same page, in the same consent state. It deliberately does not count single-page-app navigation, a re-send after consent changed, or a site that sends each hit to its own server container and to the vendor.
A scan cannot place an order, so it does not see your Purchase event. But a tag installed twice usually doubles PageView on every page too, and that the scan does see.
What the report says
This is the finding TagZ writes when it sees this fault, word for word.
Meta Pixel sent Purchase 2 times for one page view
Every order is being reported more than once, so revenue and conversion counts are inflated and bidding is learning from numbers that are not real.
Suggested fix
The tag is being initialised or triggered twice — commonly once in the site's code and once through a tag manager or a plugin. Search the page and the tag manager for the ID and remove the second install.
A scan is one look. Tags break later.
A theme update, a plugin, a new cookie banner, someone tidying up an old account: tracking rarely breaks loudly. TagZ monitoring runs this same check every six hours in a real browser and emails you when a tag that was working stops sending, after a second scan has confirmed it.
$7.99 a month for one website, billed yearly ($95.88 a year), or $2.63 a site per month on the Agency plan for 25 sites, billed yearly. See all plans.