Does Enricher truncate _fbc to 200 characters?

1

Setup: Shopify store, sGTM on Stape, Custom Loader + Enricher enabled. Purchases reach Meta by two paths — the browser (Data Tag from the checkout pixel) and a Shopify Flow webhook that fires ~3 minutes later. Both carry the same event_id, so they deduplicate correctly.

While comparing both events for the same order, I noticed the fbc values differ in length.

Browser event:

fb.1.1789989599869.IwYW9leAUd8h9w[...]RvEjxbEl_aem_Ty9iSraLFIRm4OtANEhTEQ.AQYCAQMC

Webhook event (fbc restored by Enricher):

fb.1.1789989599869.IwYW9leAUd8h9w[...]RvEjxbEl_ae

Same click — identical fb.1.<timestamp>. prefix and identical body up to the cut. But the webhook version stops mid-token.

The cut lands at exactly 200 characters. The browser value is 233. The missing 33 characters are the tail of the fbclid itself.

I pasted both into an editor and counted twice, so it isn’t a log-rendering artifact.

The Enricher page documents length limits with silent truncation, but only for profile uploads via the Profiles tab (ExternalID 64, Street 128, names/city 64, phone/postal 32). _fbc and _fbp are listed among the stored cookies with no length caveat, and I couldn’t find a 200-character limit documented anywhere.

Questions:

  1. Is there a 200-character limit on values Enricher stores and restores? Is it intentional?

  2. If so, can it be raised, or is there a way to configure it?

  3. Does the same cap apply to other stored parameters — _ttp, ttclid, _gcl_aw, _scid?

2

Thank you for bringing this to our attention and for providing such detailed technical context.

1-2 Yes, there was a 200-character storage limit in place. Since most fbclid values fall under this length, it went unnoticed, but as you pointed out, Meta’s parameters can exceed it. We are already working on a fix to increase this limit so longer tokens aren’t truncated.

3 Yes, this limit increase will apply across all stored parameters and click IDs (_fbc, _fbp, _ttp, ttclid, _gcl_aw, _scid, etc.).

3

@Dmytro thanks a lot for your reply. This clarifies a lot! Appreciate it.

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