Free tool
UTM builder and validator
Build clean campaign URLs and catch the small mistakes that wreck attribution: missing fields, mixed case, stray spaces, illegal characters.
Where the traffic comes from. Example: newsletter, twitter, awin.
Marketing channel type. Example: email, cpc, affiliate.
Campaign name or theme. Example: spring_sale_2026.
Optional. Paid keyword for SEM campaigns.
Optional. Differentiates ads or links pointing to the same URL.
- Source is required.
- Medium is required.
- Campaign is required.
UTM conventions worth committing to
- Always lowercase. Analytics treats casing as different sources.
- Use underscores or hyphens, never spaces.
- Pick a campaign naming convention and document it.
{quarter}_{theme}_{channel}works well. - Never edit a published URL. Build a new one and redirect the old one.
Frequently asked questions
What are UTM parameters?
UTM tags are query string values that tell your analytics platform where a click came from. Google Analytics, Plausible, Fathom, PostHog, and Mixpanel all read them.
Are UTM tags case sensitive?
Yes. "Newsletter" and "newsletter" are counted as two separate sources. Pick one casing convention and stick with it. Lowercase is the safest default.
Can I use UTM tags on affiliate links?
Sometimes. Networks like Awin, ShareASale, and CJ accept extra parameters but may strip them on redirect. Run the final URL through our redirect chain checker before relying on it.
What characters should I avoid?
Spaces, &, ?, =, and # break parsing. Use hyphens or underscores. This builder URL-encodes everything for you, but readable values save debugging time later.
Related: Missing UTM parameters guide · Tracking parameter audit · Redirect chain checker