Testing SourceTag

After installing SourceTag, follow these steps to confirm everything is working. You’ll check four things: the script is loading, the cookie is being set, hidden fields are being populated, and form submissions contain the data.

Step 1: Verify the script is loading

Visit your site and open the browser developer tools (F12 or Cmd+Option+I on Mac).

Check the page source

Go to the Elements panel and search for SourceTag (Ctrl+F or Cmd+F in the Elements panel). You should find a script tag like:

<script src="https://cdn.sourcetag.io/scripts/YOUR_SITE_ID/st.js" async></script>

[IMAGE: Screenshot of browser developer tools Elements panel with the SourceTag script tag highlighted]

Check the Network panel

Open the Network panel, reload the page, and filter by st.js. You should see the script file loaded with a 200 status code.

If you see a 404 or no request at all:

• Double-check that you’ve pasted the script tag correctly
• Make sure you’ve clicked Generate Script in the SourceTag dashboard (the script file isn’t created until you generate it)
• Check that the Site ID in the script URL matches your site in the dashboard

[IMAGE: Screenshot of browser developer tools Network panel showing st.js loaded with 200 status]

Step 2: Check the cookie

Visit your site with UTM parameters in the URL:

https://yoursite.com/?utm_source=test&utm_medium=cpc&utm_campaign=testing-SourceTag

In developer tools, go to Application > Cookies (Chrome) or Storage > Cookies (Firefox). Look for a cookie named _sourcetag on your domain.

[IMAGE: Screenshot of browser developer tools Application panel showing the _sourcetag cookie]

Click on the cookie to inspect its value. You should see a JSON string containing fc and lc objects with your test UTM values. The fc.channel should show the matched channel (e.g. “Paid Search” if you used utm_medium=cpc), and fc.d1 should show the source value.

The channel will depend on your configured channel rules. With utm_medium=cpc, it would typically match Paid Search.

Using the console

You can also check the data via the JavaScript API. Open the Console panel and run:

// Check if the API is available
console.log(window.__sourcetag);

// Get first contact data
console.log(window.__sourcetag.getFC());

// Get last contact data
console.log(window.__sourcetag.getLC());

// Check visit count
console.log(window.__sourcetag.getVisits());

// Check days to convert
console.log(window.__sourcetag.getDaysToConvert());

[IMAGE: Screenshot of browser console showing window.__sourcetag output with test data]

Step 3: Check hidden fields before submitting

Navigate to a page with a form on it (keeping the same browser session so the cookie persists). In the developer tools Elements panel, find the <form> element and expand it.

You should see hidden input fields that SourceTag has added:

<input type="hidden" name="st_fc_channel" value="Paid Search">
<input type="hidden" name="st_fc_detail_1" value="test">
<input type="hidden" name="st_lc_channel" value="Paid Search">
...

[IMAGE: Screenshot of browser developer tools Elements panel showing hidden input fields inside a form with SourceTag values]

If the hidden fields aren’t there:

• Make sure the script has loaded (Step 1)
• Check that the form is a standard <form> HTML element
• If the form loads dynamically (e.g. in a popup), it may take a moment for MutationObserver to detect it. Try opening the popup and then inspecting.

Step 4: Submit a test form

Fill in the form with test data and submit it. Then check wherever the form data ends up:

• Email notifications: Check the form notification email. Attribution fields should be listed alongside the regular form fields.
• CRM: If your form pushes data to a CRM (HubSpot, Salesforce, etc.), check the new contact record for the SourceTag custom fields.
• Form builder submissions: If using a form builder (Gravity Forms, WPForms, etc.), check the submissions list in the form builder’s admin.

You should see values like:

Field	Value
st_fc_channel	Paid Search
st_fc_detail_1	test
st_fc_detail_2	testing-SourceTag
st_fc_detail_3	(not set)
st_fc_detail_4	(not set)
st_lc_channel	Paid Search
st_lc_detail_1	test
st_lc_detail_2	testing-SourceTag
st_fc_landing_page	/?utm_source=test&utm_medium=cpc&utm_campaign=testing-SourceTag
st_lc_landing_page	/?utm_source=test&utm_medium=cpc&utm_campaign=testing-SourceTag

Fields that have no value (e.g. st_fc_detail_3 when no utm_term was provided) show (not set) rather than being left blank. This is expected.

[IMAGE: Screenshot of a form submission notification email showing SourceTag attribution fields]

Testing different channels

To test various channel categorisations, visit your site with different URL parameters:

Channel to test	URL to use
Paid Search	?utm_source=google&utm_medium=cpc&utm_campaign=test
Paid Social	?utm_source=facebook&utm_medium=cpc&utm_campaign=test
Email	?utm_source=mailchimp&utm_medium=email&utm_campaign=test
Display	?utm_source=google&utm_medium=display&utm_campaign=test
Direct	Visit the bare URL with no parameters and no referrer (open a new incognito window and type the URL directly)

For Organic Search and Organic Social, you’d need to actually arrive via a search engine or social network, as these are detected by referrer rather than UTM parameters.

Testing first contact vs last contact

1. Open an incognito/private browsing window (to start with a clean cookie)
2. Visit with UTMs: ?utm_source=google&utm_medium=cpc&utm_campaign=first-visit
3. Check the cookie. Both fc and lc should show Paid Search / google.
4. Wait a moment, then visit again with different UTMs: ?utm_source=facebook&utm_medium=cpc&utm_campaign=second-visit
5. Check the cookie again. fc should still show google/first-visit. lc should now show facebook/second-visit.

Troubleshooting test failures

If something isn’t working, see Troubleshooting for common issues and fixes.