UTM Link Builder

What it does

Builds campaign tracking URLs from a destination address and the five standard utm_* parameters (utm_source, utm_medium, utm_campaign, utm_term, utm_content). Parameters are appended in canonical order, any stale utm_* values already on the URL are replaced, and every other query parameter is kept untouched. A validator flags the things that break attribution: a missing utm_source or utm_medium, spaces or non-ASCII characters inside a value, an unescaped ? or #, and a destination that is not absolute http(s). Paste an existing tracking URL to split it back into editable fields.

Everything runs locally in your browser. Nothing is sent anywhere.

How to use

1. Paste your destination URL (with or without https://) and fill in the parameters — utm_source and utm_medium are recommended for GA4 attribution.
2. Pick a preset (newsletter, Twitter/X, GitHub README) to fill the whole form with a working starting point.
3. Paste an existing tracking URL into Paste an existing tracking URL to import it back into the editor.
4. Copy or download the built link; fix anything the notices flag.

The full form is encoded in the page URL, so copying the address bar shares the tool with your parameters filled in.

Examples

https://example.com/ + source newsletter, medium email, campaign august-launch produces:

https://example.com/?utm_source=newsletter&utm_medium=email&utm_campaign=august-launch

An existing value is replaced, not duplicated: https://example.com/?utm_source=old + source new produces https://example.com/?utm_source=new.

A campaign named My Campaign triggers a notice — GA4 expects lowercase with hyphens, so use my-campaign.

Good to know

• The

  hashhashA one-way function that maps data of any size to a fixed-length digest. Same input, same digest; any change, different digest; not reversible.

  fragment is preserved: parameters are inserted before #section.
• Non-utm query parameters survive unchanged, in their original order.
• Import strips every utm_* param from the base — unknown keys like utm_id are dropped, the five standard keys are recovered.
• The built link can be handed straight to the URL Inspector for a full structural breakdown.