UTM Builder: Tag Your Campaign URLs

How to use the utm link builder

1. Paste your destination URL into the Base URL field. Any existing query parameters or hash fragments will be kept intact.
2. Fill in the required UTM parameters: utm_source, utm_medium and utm_campaign. These three are mandatory for most analytics platforms.
3. Optionally add utm_term, utm_content or utm_id if your tracking setup requires them.
4. Toggle Lowercase all values to normalize casing, which prevents duplicate entries in reports.
5. Copy the generated tagged URL from the output area and use it in your campaigns.

How UTM Parameters Work

UTM (Urchin Tracking Module) parameters are key-value pairs appended to a URL after a question mark. When a visitor clicks the link, analytics tools read these parameters and attribute the session to the correct source, medium and campaign.

The five standard parameters are:

• utm_source: where the traffic originates (e.g., google, newsletter).
• utm_medium: the marketing channel (e.g., cpc, email, social).
• utm_campaign: the specific promotion or product name.
• utm_term: the keyword for paid search ads.
• utm_content: differentiates multiple links on the same page or ad variations.

An optional sixth parameter, utm_id, carries a campaign ID, which GA4 reads as the campaign ID dimension.

Building the Query String Correctly

A common mistake when using a campaign URL builder is overwriting existing query parameters or placing UTM tags before the URL fragment. The correct structure follows RFC 3986:

scheme://host/path?existing=params&utm_source=x&utm_medium=y#fragment

If the base URL already contains a question mark, new parameters must be joined with an ampersand (&). If there is no question mark, the first UTM parameter starts with one. The fragment identifier (the part after #) must always remain at the very end of the URL, because browsers do not send fragments to the server and placing parameters after a fragment breaks tracking.

This UTM link builder handles that logic automatically. It parses the input URL, separates the fragment, checks for existing query parameters, appends only non-empty UTM fields, percent-encodes special characters like spaces and ampersands, replaces any UTM parameter of the same name that is already in the URL, and reattaches the fragment. A bare domain such as https://example.com gets its implicit / path.

GA4 and HubSpot Compatibility

Both Google Analytics 4 and HubSpot rely on the same standard UTM parameters. A GA4 UTM builder does not use a different format than a HubSpot UTM builder; they both read utm_source, utm_medium and utm_campaign from the incoming URL.

The difference lies in how each platform reports the data. GA4 groups traffic into default channel groupings based on combinations of source and medium. For example, a source of google and a medium of cpc maps to "Paid Search". HubSpot records the same UTM values on contacts and sessions so you can report on them next to its own source properties.

To ensure compatibility across both platforms, keep your naming conventions consistent. Use lowercase values, avoid spaces (use underscores or hyphens instead), and never reuse the same campaign name for different channels.

Common UTM Naming Conventions

Inconsistent naming is the primary reason campaign data becomes fragmented in analytics reports. Below is a reference table of recommended conventions:

Using the lowercase option in this tool enforces the first rule automatically, preventing duplicates caused by mixed casing like Google versus google.

Verifying URLs Programmatically

After generating links with a UTM builder, you can verify them programmatically. In Python, the urllib.parse module makes this straightforward:

from urllib.parse import urlparse, parse_qs
parsed = urlparse(tagged_url)
params = parse_qs(parsed.query)
print(params.get('utm_source'))

This confirms that the parameters were attached correctly and that the fragment was not corrupted. You can also paste the final URL into a tool like the URL encoder to inspect how special characters are percent-encoded.

Worked examples