How to Verify Tag Changes with Google Tag Manager in Preview Mode

July 27, 2015 Clint Eagar

(This post takes 3 minutes to read)

Complex changes to your measurement implementation need to be performed very carefully to ensure data remains consistent and that updates don’t break existing configurations. Whatever variables you change, ObservePoint can verify them! Follow this guide to audit and verify changes made in Google Tag Manager (GTM) before publishing the updates.

In this example we added two custom dimensions to our Google Universal Analytics tag: cd1 = GTM version and cd2 = hostname. In the ObservePoint audit data we should expect to see cd1 = QUICK_PREVIEW and cd2 =


1. Make changes in Google Tag Manager.

2. Click the red arrow next to Publish and choose Preview.

3. Preview Mode is now enabled. Click the Share Preview link.  

4. Copy the Share Preview link. Note that once you have the Share Preview link you can turn off Preview Mode and the link is still valid and can be used at anytime.

5. Head over to and configure your audit as normal. Be sure to select “Record new user session” and to click Save at the bottom of the page.

6. Name the audit login whatever is convenient. Input the Share Preview link in the address field.

7. Make sure to click Save.

Your audit will now run and set the GTM preview mode cookie before visiting pages. Verify that that the changes we made executed correctly with our Business Compliance Rules System, Advanced Export, or a Full Vendor Export. Remember in this example we should expect to see cd1 = QUICK_PREVIEW and cd2 =

Here is the ObservePoint Advanced Export showing that these variables have been configured correctly:


About the Author

Clint Eagar

Clint gets things done. He has been building websites, marketing and optimizing them for 15 years. He claims to know a little bit about a lot of things and is relied on to execute anything quickly. Clint has been with ObservePoint since the early days and has helped support, test, and promote the product. Before coming to ObservePoint he was at OrangeSoda, running the enterprise SEO team, and before that he was a business consultant at Omniture.

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