Are there tags that Google Tag Manager does not support?
Google Tag Manager does not support:
- Synchronously loading tags.
- Certain tags with snippets in the header and the footer. While you can use event based rules on gtm.load to fire some of these tags (see the developer documentation), two-part tags usually imply some need for synchronously loading tags.
- Tags that are associated with in-page structure, such as social sharing widgets or ad serving tags.