How to Track HubSpot Forms with Google Tag Manager

This guide shows how to track HubSpot form impressions and successful submissions with Google Tag Manager and GA4.

The lightweight v1 template listens for HubSpot form events, pushes clean source-specific events into the dataLayer, and maps those events to GA4 reporting events.

Download the GTM template

Use this downloadable GTM container template to track HubSpot form impressions and successful submissions.

Download the HubSpot form tracking GTM template

This template includes:

• A lightweight HubSpot form listener
• A hubspotFormImpression dataLayer event
• A hubspotFormComplete dataLayer event
• A hubspotFormId dataLayer variable
• GA4 mapping to form_impression
• GA4 mapping to generate_lead
• A form_id event parameter

What this setup tracks

This v1 template tracks two HubSpot form events:

• hubspotFormImpression when the HubSpot form is ready or detected on the page
• hubspotFormComplete after a successful HubSpot form submission

GTM maps those source-specific dataLayer events to cleaner GA4 reporting events:

• hubspotFormImpression → form_impression
• hubspotFormComplete → generate_lead
• hubspotFormId → form_id

What this setup does not track

This template does not collect form field values, names, email addresses, company names, messages, phone numbers, or other PII.

It also does not include a form_start event in v1. A true form-start event should be defined carefully, tested against the specific HubSpot embed type, and deduplicated so one visitor cannot create multiple starts from the same form instance.

Why this template separates dataLayer events from GA4 events

The dataLayer events are source-specific because they describe what happened in HubSpot:

• hubspotFormImpression
• hubspotFormComplete

The GA4 events are reporting-specific because they describe the business behavior you want to analyze:

• form_impression
• generate_lead

This separation keeps the implementation clear. HubSpot-specific behavior stays in the dataLayer, while GA4 receives normalized events that can be reused across future form, scheduler, chat, or quiz tracking.

How to validate the setup

After importing the template, test the setup in GTM Preview before publishing.

Expected dataLayer events:

• hubspotFormImpression when the HubSpot form loads
• hubspotFormComplete after a successful submission

Expected GA4 events:

• form_impression
• generate_lead

In GA4 DebugView, confirm that the events include the form_id parameter.

Do not publish the container until the events appear correctly in both GTM Preview and GA4 DebugView.

Turn these events into GA4 funnel rates

After you capture HubSpot form impressions and successful submissions, the next step is to turn those events into reusable GA4 custom metrics and calculated rates.

Read the connected guide: How to Build Custom & Calculated Metrics in GA4 for Funnel Rates.