Pixel warming, explained
A fresh pixel knows nothing. Before Meta or TikTok can optimise delivery or build useful audiences, the pixel needs conversion signal — real events tied to real users. Pixel warming is the practice of feeding that signal in, usually from conversions you already have in your tracker.
Why warm a pixel server-side
You can warm a pixel by sending events through the Conversions API (CAPI) — straight from your server, with no pixel code on a website. That's the only option when:
- you run chat or offline funnels (no website to host the browser pixel), or
- you want to replay historical conversions from a tracker like Keitaro.
Server-side events also carry richer matching data (hashed email, phone, external ID), which improves how many events Meta can attribute.
The 7-day limit — read this first
The Conversions API will not accept an event whose event_time is more than
7 days in the past (error 2804003) or in the future (2804004). So you
can only warm with recent conversions — dumping months-old data does
nothing.
Most handles the boundary for you: it clamps each event's event_time to a safe
window (about now − 6 days) so edge cases don't get rejected, while keeping the
original conversion time inside the event identity. See
event_id & deduplication for why that matters.
How to warm with Most
- Connect your Keitaro source and load recent conversions.
- Map the Keitaro statuses you care about to standard pixel events (Purchase, Lead, CompleteRegistration, …).
- Send. Most pushes the events through CAPI on your schedule and deduplicates automatically, so re-runs and incremental loads never double-count.
Want to feel it out first? Fire a few events by hand with the free Pixel Activator, watch them land in Events Manager, then automate the flow in Most.