Meta Pixel + Conversions API (CAPI) Setup: A Checklist for When Conversions Won't Track
ImageFactory Engineering · Published 2026-06-18
If your Pixel is clearly installed but Ads Manager shows almost no conversions, the install probably isn't broken. A browser-only Pixel naturally misses 30-40% of conversions because iOS 14's tracking consent (ATT), Safari's ITP, and ad blockers suppress it. The fix is well-established: run the browser Pixel and the server-side Conversions API (CAPI) together, then deduplicate with a shared event_id. Here's the order to check.
The Pixel is installed, so why aren't conversions tracking?
When iOS 14.5 launched App Tracking Transparency (ATT) in 2021, users could opt out of tracking. At the same time, Safari's Intelligent Tracking Prevention (ITP) expires JavaScript-set cookies (like _fbp) after seven days, and ad blockers intercept the Pixel request outright. The result: the Pixel everyone once relied on misses 30-40% of conversions on average, and without server-side tracking, attribution accuracy can drop to around 40% or lower (Dataally, 2026).
So a "missing conversions" problem is usually structural signal loss in the browser, not an install mistake. Before you re-check the install, check whether you're running Pixel-only.
Why do I need both the Pixel and CAPI?
The Conversions API (CAPI) sends user actions to Meta from your server, not the browser. ATT can't block a server call, ITP can't expire a cookie it doesn't depend on, and ad blockers can't intercept server-to-server traffic. That's why Meta officially recommends "dual tracking" — Pixel plus CAPI together (Upstack Data).
The performance gap is real. Event capture rises from roughly 60-70% on Pixel alone to 95%+ with CAPI properly attached, and reports show a lower average cost per result versus Pixel-only setups (Dataally, 2026). You typically have three implementation paths: (1) your store platform's built-in CAPI integration (Shopify, etc.), (2) a Google Tag Manager (GTM) server-side container, or (3) a direct developer implementation via the Conversions API. For modest traffic, the built-in integration or a GTM server container is the fastest route.
How do I get event_id deduplication right?
With both Pixel and CAPI on, the same purchase arrives twice. Merging those into one is deduplication, and the key is the event_id. Meta treats two events as the same conversion — and counts it once — only when both event_name (e.g., Purchase) and event_id match (Dataally, 2026).
The rule is simple: generate one unique event_id per user action and send the exact same value through both the Pixel and CAPI. An order ID or UUID works well. The catch — a difference of casing or even a single space breaks deduplication and double-counts the event. If your conversion count suddenly doubled, an event_id mismatch is the usual culprit.
How do I raise Event Match Quality (EMQ)?
Event Match Quality (EMQ) is a 0-10 score for how well the conversion signal you send matches Meta user profiles. A higher score means cleaner signal, so Meta's machine learning optimizes toward real conversions and drives cost per conversion down (Upstack Data).
Meta's internal benchmark sits around 6 out of 10, and Purchase events ideally land in the high 8s to low 9s (Dataally, 2026). The surest way up is to send as much customer information as possible with each server event, always hashed with SHA-256 — email, phone, name, zip — and adding hashed email in particular lifts the score noticeably. Send refreshed fbp and fbc cookie values too. Never send plain-text email or phone numbers.
Why do marketplace pages only capture clicks?
External marketplaces — Naver Smart Store, Coupang, Amazon — own the checkout and confirmation pages, so you can't place your own Pixel or CAPI there. The ad click and landing get tracked, but the actual "purchase" signal never returns to Meta. A conversion-optimization campaign has no data to learn from.
You realistically have two options: (1) manage marketplace traffic on click and traffic metrics only, and judge conversions from the marketplace's own reporting, or (2) if conversion data matters, route traffic to your own store where you can install Pixel and CAPI. Either way, go in knowing that marketplace traffic alone can't power Meta's conversion optimization. To rework the targeting layer itself, pair this with our Meta targeting and audiences guide.
Checklist
- When conversions won't track, first confirm it's a Pixel-only setup, not an install bug
- Turn on both the browser Pixel and server-side CAPI (built-in integration / GTM server container / direct build)
- Generate a unique event_id per user action and send the identical value to both Pixel and CAPI
- Match event_name and event_id exactly, casing and whitespace included, to confirm deduplication (doubled counts mean a mismatch)
- Send customer info (email, phone, name) SHA-256 hashed to push EMQ above 6, and Purchase into the 8s
- Use the Test Events tool in Events Manager to verify both sources arrive and deduplicate correctly
- Accept that external marketplaces capture clicks only — if conversions are the goal, evaluate an owned-store path
How ImageFactory fits in
Once tracking is accurate, Meta's algorithm starts optimizing toward real conversions instead of clicks. From that point, the lever that moves performance shifts from data to creative volume and quality — the algorithm learns faster when it has enough creatives to test.
ImageFactory automates that creative supply. From a single master or a cut-out product shot, it builds style variations and adapts them — text and logo preserved — across 1,400+ ad placements and 110+ platforms. Safe zones apply automatically, distortion stays at 0-2%, and it supports 2K/4K output in 15 languages, with Figma and Photoshop plugins. After your tracking is solid and you want to scale up the creatives you test, a 14-day free trial lets you see per-placement auto-adaptation first. If you're moving into the budget-scaling phase, our ad budget scaling guide is a useful companion.
(Note: ImageFactory automates ad-creative production and adaptation. It does not install or manage conversion tracking such as the Pixel or CAPI.)