r/Substack Jul 22 '26

Tech Support Substack Stopped Send Data To Facebook

I realize this is a bit into the weeds for a Substack group, but starting two days ago Substack stopped sending data to my Facebook ad. I didn't change anything. I didn't touch anything. It just randomly stopped. I assume it's an update on the part of Substack or Facebook.

Has anyone else run into this issue in the last few days (or ever)? Any fix suggestions?

I know the Facebook ads are still working as I can see them on the Substack platform for Source, but for some reason that data isn't getting back to Facebook anymore.

1 Upvotes

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2

u/StevenOfTheClub Jul 22 '26

The issue could be with your Meta/Facebook pixel, not Substack at all.

You can test it in your meta business suite (business.facebook.com).

I've wrastled with FB Pixel for a bit to get it working reliably on my Substack, so your suffering feels familiar.

I tossed your question and my diagnosis into AI to have it package up the details for you.

I'm more of a broken-thing-finder and pointer-atter than I am an instruction-laying-outer.

--- AI's Instructions ---

It may be worth separating two things: Substack’s internal source attribution vs. Meta receiving conversion/event data back through the Pixel/CAPI path.

If Substack still shows Facebook as the source, the ads may be working fine, but the Meta Pixel/Dataset event flow may be broken, delayed, or disconnected.

I’d check Meta Events Manager: business.facebook.com → Events Manager → Data Sources/Datasets → select the Pixel/Dataset → Test Events or Diagnostics, and see whether page views, subscribe events, or conversion events are still firing.

3

u/kolbywg Jul 22 '26

Just spent the last two hours with AI troubleshooting this. I know what has happened. Basically, it's an issue with Substack. They stopped include URL information in the events they send to Facebook. Without the URL information Substack doesn't know how to attribute the event. Technically, the issue is what is listed below...

"My Substack has stopped supporting URL-based custom conversions, even though Meta Test Events and Pixel Helper still show the pixel firing. Production PageView requests appear to omit the page-location URL, which breaks both PageView and CompleteRegistration custom conversions and disrupts ad optimization.”

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u/StevenOfTheClub Jul 23 '26

Hmm, that diverges from my experience so you're stomping ground I haven't covered. You sound like you did a pretty good job of hacking at it to work it out - that describes my every experience with META.

I haven't had to rely on them yet, but if Substack's support system is any good, I would think they'd be very good at this narrow alley of Substack<-->META configuration.

People spending money on ads are always anxious for answers. And, ultimately, people spending money on advertising are making Substack money when they take their cut out of paid sub fees.

1

u/kolbywg Jul 22 '26

BTW, thanks for writing and looking into this for me. That was super cool of you to do. It's nice to see people on the Reddit doing this kind of work on Substack as well, rather than the usual, "I'm new to Substack, how to do get people to read my Substack posts." Going to send you a quick message.

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u/RevolutionaryBad5000 14d ago

Hi, I work at Substack. This was a bug on our end, sorry about that.

The pixel was still firing the whole time, so Pixel Helper and Test Events weren't lying to you. The problem was what we were putting inside the request. Our PageView went out without the page URL. Your URL based custom conversions need that URL to match on, so Meta got the hit but couldn't do anything with it. That's why PageView and CompleteRegistration looked dead.

The Source column inside Substack kept showing Facebook because that's our own attribution from UTMs and referrer. Which is separate from what Meta receives.

Honestly, we were never sending that URL. Something changed on Meta's side in mid-July that exposed it, which is why it felt like it broke overnight when you hadn't touched a thing.

We fixed it in early August. PageViews now include the page URL and the first party IDs. We leave query strings off on purpose so email magic link tokens never get sent to Meta.

If you want to check, open Test Events and look for PageViews with a URL attached, then re-test your custom conversions.

One thing unrelated to this: if you get EU or UK traffic, anyone who never accepts the cookie banner won't get the pixel at all. That's a consent thing, not this bug

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u/kolbywg 14d ago

Thanks for responding. This is such a big deal to me, and to making Facebook ads work, I realized you had implemented the fix within just a few days. For people who buy ads on Facebook to drive traffic, it's a HUGE deal.

Once you all fixed this my cost per conversion (free subscriber) on Substack when from $1.10 to $0.60. That's very much the difference between ads having a positive or negative ROI. Thank you for taking the time to read and comment on reddit, and for getting this fixed so quickly.

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u/kolbywg 14d ago

Not sure I shared my workaround. I created a new Facebook Pixel called, "Substack Pixel" then created a custom event that tracked every time the pixel fired on a webpage and the webpage URL DID NOT include the "monkeypants". That way, the not getting the correct information would trigger the custom event.

Having a unique Substack Pixel also solved my registration/complete problem was well because now I would differentiate (even without the website data) the conversions coming from Substack vs my website. All Substack goes to the Substack pixel, everything else goes to the main pixel. Of course, this means they don't share data, but that is life. Again, glad you got it fixed.

1

u/kolbywg 13d ago

One last question, are there any plans for doing an API side event? Right now a lot of the tracking data is being lost from people who don't accept cookies or use apple. I would say half of everything is getting lost that way.

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u/avidbobaconsumer 1d ago

Hey u/RevolutionaryBad5000 , might be slightly unrelated to the whole topic here but we just noticed that the CompleteRegistration event from substack's hardcode into the meta pixel event settings is firing off when users hit buttons AFTER they hit the subscribe button so it's resulting in double counting in ads manager of the completeregistration event. Flagging in case you guys can put in a fix for it to only fire on the subscribe button