Why do you need two ways to send the same event?
Because the browser stopped being a reliable messenger. The Pixel runs inside the visitor's browser, and since 2021 a growing share of browsers and phones refuse to run it or strip what it sends. Apple's App Tracking Transparency, introduced with iOS 14.5, asks iPhone users whether an app may track them, and most say no. Safari limits how long a tracking cookie can live. Ad blockers remove the Pixel outright. Each of those turns a real purchase into an event Meta never hears about.
The Conversions API sidesteps the browser. When an order is placed, your website's server sends Meta the event directly, with a hashed email or phone number so Meta can match it to the person who saw the ad. Meta's own guidance (Meta Business Help Centre, "About the Conversions API") is to run both, which it calls a redundant setup: the Pixel for what it can still see, the API for what it cannot, with Meta removing the duplicates.
What does the Pixel actually send?
Events. A standard set has names Meta understands: PageView, ViewContent, AddToCart, InitiateCheckout, Purchase, Lead, Schedule, Contact. Each can carry a value and a currency, which is how Meta works out the revenue behind a ROAS figure. You choose which events count as a result for a campaign, and Meta's bidding then chases that event.
If your site sends only PageView, Meta can see that people arrived and nothing else. A campaign set to "maximise purchases" with no Purchase event has nothing to aim at and spends the budget on the people most likely to visit, which is a different crowd from the people most likely to buy.
What happens when a business has neither? (example figures)
A Hobart homewares shop on Shopify runs Meta ads at $1,800 a month. The Pixel was never connected and the Conversions API setting in Shopify was never switched on.
| Without either | Pixel only | Pixel and Conversions API | |
|---|---|---|---|
| Purchases Meta can see | 0 | Roughly half to two thirds of them, depending on how many customers use iPhones | Nearly all of them |
| What the campaign aims at | Clicks or page views | The purchases it can see | The purchases it can see, which is most of them |
| What the owner sees in Ads Manager | Spend and clicks, no revenue | A ROAS that undercounts | A ROAS close to the shop's own figure, less the attribution gap |
| Retargeting | Impossible | Partial audiences | Full audiences |
In this shop, switching on the Conversions API inside Shopify is one setting on the Facebook and Instagram sales channel page. Meta then matched purchases it had been missing, the campaign's learning phase restarted with real purchases to aim at, and the owner could at last read a ROAS in Ads Manager that was in the same postcode as the Shopify sales report. The $1,800 did not change. What it bought did.
How do you know whether yours is working?
Open Events Manager in Meta Business Suite. Your Pixel is listed with the events it received in the last 28 days, and each event shows whether it arrived from the browser, the server, or both. A healthy shop shows Purchase arriving both ways with a high event match quality score, which Meta rates out of 10 on how well the hashed details match real accounts. A Pixel with only PageView, or a Purchase event received from the browser alone, is the thing to fix before judging any campaign.
What does Cora do with the Pixel?
CoraVision reads your Meta campaigns and ad sets every night once Meta is connected: spend, impressions, clicks, and the results and their value that the Pixel and the Conversions API reported. A Pixel that is missing or half-connected shows up as results that do not match your shop, and your Trust Score, which rates how far the numbers can be trusted, loses points for a paid channel with no conversion tracking. Fixing it is a step in your action plan, and Mira, the Meta Ads specialist, talks you through Events Manager on your own screen while you do it. CoraVision never changes anything in your Meta account itself.
Questions
Do I need the Conversions API if I already have the Pixel?
Yes, if you sell or take bookings on your website. The Pixel alone misses the visitors whose browser or phone blocks it, which since 2021 is a large share of iPhone users. Meta calls running both "redundant setup" and recommends it. Shopify, WooCommerce and most booking tools turn the Conversions API on with a setting rather than code.
Why does Meta report more purchases than my shop does?
Meta counts a purchase as its own if the buyer clicked or saw an ad in its attribution window, which by default is seven days after a click and one day after a view. Your shop counts every order. The gap is attribution, not a fault, and the number to trust for money decisions is the shop's.
Is the Pixel a privacy problem for my customers?
It is a tracker, and in Australia it is lawful with a privacy policy that says you use it. Your customers' browsers decide what it can see, which is why its numbers are incomplete. If you serve people in Europe or the UK, a consent banner is required before it fires.