Update time: January 15, 2025
There are two features in GTM that can control the execution speed of Tags.
Tag Firing Priority
Tag Firing Priority: Determines the order in which tags will be fired. The setting location is in Advanced Settings：
The value can be a positive or negative integer, default is 0, and tags with higher values will fire before those with lower values, for example, a priority 99 tag will fire before a priority 10 or 20 tag.
Tags will still be fired asynchronously, i.e., a tag will be fired whether or not the previous tag has finished, tag Firing Priority emphasizes who starts execution first, It may happen that some tags start slowly and end quickly, eg:
Tag Sequencing
Tag sequencing enables you to specify tags to fire immediately before or after a given “primary” tag is fired, the setting location is in Advanced Settings：
There are two types:
- Fire a s tag before <this tag> fires: A setup tag fires before the primary tag
- Fire a s tag after <this tag> fires: A setup tag fires after the primary tag
There is a big difference, Tag Sequencing emphasizes the order of precedence, the execution order of tag sequencing is to finish executing Tag A and then execute Tag B:
If check 「 」，If Tag A fails to execute, Tag B will not execute.
Summary
Tag Firing Priority emphasizes who starts execution first, If different tags have no dependency relationship, use Tag Firing Priority.
Tag Sequencing emphasizes the order of precedence, If different tags have dependency relationship, use Tag Sequencing.
