Do I still need the pixel if I use the Conversions API?
Short answer: you can run without the pixel, but Meta generally recommends using both together, and for most advertisers that is the better setup. The pixel gives you page-level signal and browser data that a server alone has to be handed.
So the real question is not whether you can drop it, but what you lose if you do.
Here is a made-up story. A software company called Brightleaf turned its pixel off after reading that CAPI was enough. For two weeks nothing seemed wrong. Then they noticed that their retargeting audiences had stopped growing, and that Meta was reporting fewer leads than their form tool showed. The server events were fine. What they had lost was the stream of who visited which page, which is what audiences are built from.
That is the first thing the pixel gives you: audiences and page context. Website visitors, product viewers and people who reached the pricing page are all built from browser activity. A server that only reports purchases cannot describe the people who looked and left.
The second is browser identifiers. The fbp and fbc values are set and read in the browser. A server can pass them along, but only if something on the page captured them first. Without a pixel, someone has to build that capture by hand.
The third is simplicity. When events arrive from two places, Meta can cross-check them. If one path breaks, the other still tells you something happened. Running one path with no backup means a single silent failure can leave you blind for weeks.
So when is a server-only setup reasonable? A few cases. If you run mostly in-app or offline sales and the website matters little. If your site legally cannot load third-party scripts. Or if you already send rich page events from your own server. In those cases you do without the pixel on purpose, and you accept that audiences and browser data need another route.
If you keep both, the one rule you cannot skip is deduplication. Every event that both sides send needs the same event name and the same event_id. Meta keeps one and discards the other, but only when those match. Check this in Test Events: fire one action and confirm it appears once, marked as deduplicated, not twice.
Another honest point: neither approach removes the need for consent where you operate. If a visitor has not agreed, you should not be sending their data through either path. The server route does not make that question go away.
And a caution on cost of change. If the pixel works today and your numbers look reasonable, do not rip it out to look modern. Add server events beside it, watch match quality and the Test Events results for a few weeks, and only then decide what you truly do not need.
Did you turn the pixel off already, or are you deciding whether to?
More on this: How Meta CAPI fits with your pixel, and the complete guide to offline conversion tracking.