About
UTM Stickler by Cobblekit is a free Firefox (desktop) add-on that checks UTM links for typos and inconsistent tags against your naming rules. Load the built-in example rule set in one click, or import your own. It catches misspelled keys like utm_souce or utm_campain, uppercase keys like UTM_Source, and case mismatches like Newsletter vs newsletter (when your rules use lowercase, as the example set does). It flags aliases like fb → facebook only when your rules list them. Other checks: the same utm_* key twice, UTMs after "#", unencoded spaces, values not on your approved list, and missing required tags. Check the current page or scan its links, build a tagged link from your rules, or paste a list of links. Everything runs on your device: no account, no data collected. It reads the standard utm_* keys GA4 recognises but has no Google Analytics integration.