Validation in GTM Preview
After publishing the tag to your workspace:
- From the Tags page, click Preview in the top-right corner.
- In Tag Assistant, enter your site URL and click Start.
- Perform an action that should fire an event.
- Right-click → Inspect → Console tab and look for the event name under
dataLayer.
- Back in Tag Assistant, click Continue → check Tags Fired for Zeotap Collect.
- Log into the Zeotap CDP, open your GTM Source, and watch the PREVIEW tab for the incoming event.
If the tag fires but the event doesn’t appear in the CDP, check the browser Network tab for failed POST requests to spl.zeotap.com.
Troubleshooting
| Symptom | What to check |
|---|
| Tag template not found in the Gallery. | Confirm you searched for Zeotap Collect Tag Template (exact name). If still missing, request the .tpl file from your Zeotap POM and import manually. |
| Tag doesn’t fire. | Confirm a trigger is attached. Check the trigger conditions in Tag Assistant — most often the regex doesn’t match the actual event name. |
| Tag fires but no events appear in the CDP PREVIEW tab. | Verify the Write Key matches the GTM Source. Check the network tab for failed POSTs to spl.zeotap.com. |
| Identities aren’t being captured. | Confirm the Login Event field matches the dataLayer event you push on login. Confirm the identity variables resolve correctly in Tag Assistant. |
| PII isn’t being hashed. | Confirm Is hashing of raw identities required? is checked and the reserved key names (email, cellno, loginid) are mapped to the right variables. |
| Custom consent isn’t being applied. | Confirm Consent Method is set to Custom Consent and the consent event has been pushed to the dataLayer before any other tracking events. |
| GA Client ID isn’t appearing in payloads. | Confirm Pick Google Analytics client ID is checked and the cookie prefix matches your GA setup. Default GA cookie is _ga. |
| Cross-domain identity stitching is broken. | Enable Persist data in cookie storage under Initialisation Options. |
FAQ
What’s the difference between the GTM tag and the Web JS SDK?
The GTM tag is a wrapper around the Web JS SDK. Same backend, same payload shape, same consent flows — but configured through the GTM UI instead of code on your site. Use GTM if you can’t modify site code, or if your marketing team already manages tags through GTM.
Can I use the Zeotap GTM tag alongside the Web JS SDK on the same site?
You should pick one or the other — running both would double-count events. If you’re migrating from one to the other, do it in a single change.
Does the GTM tag respect TCF?
Yes. With Consent Method set to Check TCF CMP, the tag reads the TCF API on the page and queries the publisher’s consent before recording events. Configure Purposes for tracking to match your TCF setup.
How does the tag handle single-page apps?
For SPAs, push a pageView event to the dataLayer on every route change. The tag will pick it up and run setPageProperties on each one.
What if my dataLayer event name isn’t event?
Override Event Key under Initialisation Options with your custom key name.
How do I send brand consent?
Use Additional Consent Settings in the template to map brand consent fields to dataLayer variables. Brand consent works under any Consent Method — default opt-in, TCF, or custom.
My events have raw email in the payload. How do I strip it?
Add email (and any other raw PII) to PII to be excluded under Tracking. The tag drops these keys from event properties before sending.
Do I need a separate Source for staging and production?
Yes — each Zeotap CDP Source has its own write_key. Create one Source per environment so you can isolate staging traffic from production.
What CMP vendor IDs do I need?
- Vendor ID 1469 — required for first-party data tracking.
- Vendor ID 301 — required if cookie sync is enabled.
Make sure both are present in your CMP configuration.Last modified on June 22, 2026
