Tag Firing Priority vs. Tag Sequencing in Google Tag Manager

Update time: January 15, 2025

Let’s say that two tags fire at the same time in Google Tag Manager (GTM).

You want Tag A to run before Tag B. Should you use Tag Firing Priority or Tag Sequencing?

The answer depends on what you are trying to achieve:

• Use Tag Firing Priority when one tag should start first.
• Use Tag Sequencing when one tag must run before or after another tag.

These two features may sound similar, but they work differently.

Tag Firing Priority 

Tag Firing Priority determines which tag starts first when multiple tags fire during the same GTM event.

To find this setting, open a tag and go to「Advanced Settings」——「Tag Firing Priority」：

The default priority is 0. You can enter a positive or negative integer.

A tag with a higher value starts before a tag with a lower value.

For example:

When both tags fire during the same GTM event, GTM starts Tag A before Tag B.

But here is the important part: GTM does not wait for Tag A to finish before starting Tag B.

The tags still run asynchronously. Therefore, the following situation is possible:

Tag A starts first → finishes second
Tag B starts second → finishes first

In other words, Tag Firing Priority controls the starting order, not the order in which tags finish.

Tag Sequencing

Now imagine a different situation.

Tag B uses a value that must first be created by Tag A. If both tags run independently, Tag B may start before that value is available.

This is where Tag Sequencing is useful.

Tag Sequencing allows you to specify another tag that should run immediately before or after a primary tag.

Open the primary tag and click「Advanced Settings」——「Tag Sequencing」

You will see two options:

• 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 「 Don’t fire Untitled Tag if HTML-Set IP fails or is paused」，If Tag A fails to execute, Tag B will not execute.

Tag Firing Priority vs. Tag Sequencing

Here is a quick comparison:

Final Words

Tag Firing Priority and Tag Sequencing both affect the order in which tags run, but they solve different problems.

• Tag Firing Priority controls who starts first. The tags still run independently.
• Tag Sequencing creates a dependency. It allows a setup tag to run before the primary tag or a cleanup tag to run afterward.

Therefore, if the tags are independent, use Tag Firing Priority. If one tag depends on another, use Tag Sequencing.