Free tracking tools
Two small tools you can use without an account. Neither one proves a purchase fired. They show what a store loads and what a purchase event contains, so you know where to look first.
Shopify pixel checker
Enter any Shopify store and see every tracking pixel it runs, how each one is installed, and which of them can see checkout. It reads one public page, so it needs no login and no access.
GA4 purchase event checker
Paste a GA4 purchase event and see what Google's own reference says is wrong, such as a missing transaction_id, a value sent as text, no currency or an empty items list. It runs in your browser, and nothing you paste is sent to AuditTag.
Want the whole site read?
The free audit reads up to 25 pages and shows which tags are installed and where, plus the on-page problems underneath. What it checks, and what it cannot see is written out in full.