Facebook pixel not firing: how to test and fix it
Troubleshooting guide · 2 min read · Updated 2026-10-21 · By the Cofoundr team
Install the Meta Pixel Helper and open the Test Events tool in Events Manager, then load the page and take the action. If nothing arrives, check the pixel ID, whether the base code loads on every page, whether a consent banner or tag manager blocks it, and whether a single-page site needs events sent on route changes.
When the pixel does not fire, optimisation has nothing to learn from and results look like zero. It is also the easiest tracking problem to test directly. Work in the order below, and test after each fix.
1. Test it live
- Install Meta's Pixel Helper in your browser and load the page.
- Open Test Events in Events Manager and perform the action yourself.
- Note which events fire, which do not, and any warnings.
2. Check the install
- Is the pixel ID the right one for this ad account?
- Is the base code on every page, not only the home page?
- Is the event code on the page or action that should trigger it?
- Is it installed twice by a plugin and by hand?
3. Consent banners and tag managers
- A consent banner may block the pixel until the visitor agrees. Check your consent setup and the rules that apply to your audience.
- In a tag manager, check the trigger, the published version and the preview mode.
- Confirm events fire after consent is given.
4. Browsers and blockers
Some browsers and ad blockers limit browser-side tracking. Sending events from the server as well helps. See Conversions API not working and duplicate conversions.
5. Single-page and checkout flows
- Single-page sites may not reload pages, so events must fire on route changes.
- Hosted checkouts on another domain may need their own setup.
- A thank-you page that is reached only some of the time hides conversions.
After the fix
- Do a test purchase or test lead and watch it arrive.
- Compare Meta's count with your own records after a few days.
- Watch the gap between clicks and results.
How Cofoundr helps
Cofoundr cannot see your pixel, but it can show the symptom: the client page warns when there are many clicks and very few conversions, and wasted spend flags ad sets with plenty of clicks and no results as a possible broken funnel.
Frequently asked questions
How do I know if my Facebook pixel is working?
Use the Pixel Helper extension and the Test Events tool in Events Manager, then perform the action yourself and watch the event arrive.
Why is my pixel firing on some pages but not others?
The base code may not be on every page, or a tag manager rule or consent setting may block it on some.
Does the pixel work without cookies?
Browser tracking is limited by cookie and privacy settings. Server events help fill the gap.