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attr.so/Free tools/UTM Parameter Validator
FREE TOOL · NO SIGNUP

UTM Validator -free

Catch the silent UTM bugs that fragment your reports: missing fields, casing slips, whitespace, duplicates, and non-standard parameters - before a campaign goes live.

3severity levels
6+checks per url
∞urls / day
attr.so/tools/utm-validatorLive preview
Paste a URL with UTM parameters above to validate it.
/ 5 quick steps

How to use this tool.

~ 30 seconds end to end
  1. 01

    Paste the tagged URL

    Drop in any URL with utm_ parameters. We parse the query string and check every tag.

  2. 02

    Read the issue list

    Errors block the campaign from working correctly; warnings are bad practice; suggestions are stylistic improvements.

  3. 03

    Fix and re-paste

    Update the URL in your ad platform, email tool, or CMS, then run it through one more time to confirm clean.

  4. 04

    Build a clean one if needed

    Use our UTM Builder for a slug-safe rebuild from scratch.

  5. 05

    Track every clickOPTIONAL

    Wrap the clean URL in an attr.so short link to see every UTM on every click - without touching your GA setup.

    Make it trackable
/ Where people use it

Common use cases.

6 most popular
QA
✓utm_source = newsletter
✓utm_medium = email
!utm_campaign = Spring%20Sale
✓utm_content = button_a
USE CASE 01

Pre-launch QA

Last sanity check before a campaign goes live in front of real spend.

Agencies
utm_sourceutm_mediumutm_campaign
USE CASE 02

Agency handoffs

Validate every URL a freelancer or agency hands you before plugging it into your ad accounts.

Build
attr.so
USE CASE 03

Automated builds

CMS or marketing-automation tool building UTMs dynamically? Spot-check a sample to catch encoding bugs.

Reports
USE CASE 04

Fixing fragmented reports

utm_source=email vs Email vs EMAIL? Run your URLs through the validator and standardise on lowercase.

Email
USE CASE 05

Email campaign audits

Audit older campaign URLs that have been quietly producing bad data for months.

Team
USE CASE 06

Onboarding new marketers

Show a new hire exactly which UTM mistakes break tracking by running their first URL through the validator.

/ The difference

Free, then trackable when you need it.

vs typical free tools
⚠ Most free tools

What you usually get

  • No severity grading. Every issue is a "warning" - no way to prioritise.
  • Missing-field checks only. No catch for casing, whitespace, or duplicate parameters.
  • Sends your URL to a server. Many validators log every URL into a queryable database.
  • No fix suggestions. Tells you the URL is wrong, leaves the fix to you.
  • Confuses standard with custom. Treats utm_id and your custom utm_funnel_step the same way.
attr.so · what we ship

What you get here

  • Three severity levels. Errors, warnings, info - fix what matters first.
  • Required-field checking. Confirms utm_source, utm_medium, utm_campaign all present.
  • Case + whitespace + dup detection. The three biggest silent killers caught explicitly.
  • Standard parameter recognition. Knows the five Google UTMs + utm_id; flags everything else.
  • Runs in your browser. No URL upload, no logged history - parses locally.
/ FAQ

Frequently asked.

Can't find it? Email us
What UTM mistakes break Google Analytics?
The big four: capitalisation mismatches (Email vs email), embedded whitespace, missing required fields (especially utm_medium), and duplicate parameter names. Each one fragments your reporting silently.
Are UTM parameters case-sensitive?
Yes. Google Analytics and most other analytics platforms treat utm_source=Email and utm_source=email as separate sources. Lowercase is the safe default for the entire team.
What characters are safe in UTM values?
A-Z, a-z, 0-9, hyphens, underscores, and dots are universally safe. Spaces must be encoded; emoji and accented characters often break attribution. Stick to ASCII alphanumerics + dash/underscore.
Which UTMs are required?
Google considers utm_source, utm_medium, and utm_campaign required. utm_content and utm_term are optional. Some platforms (HubSpot, Salesforce) require utm_id too for first-party attribution.
Can I have duplicate UTMs in one URL?
No. ?utm_source=facebook&utm_source=twitter is undefined - most platforms keep one and silently discard the other. Always use exactly one of each parameter per URL.
Why does whitespace break tracking?
Browsers URL-encode space as %20, and most analytics platforms display the encoded value. utm_campaign=Spring Sale becomes utm_campaign=Spring%20Sale in your reports - ugly, hard to filter, and easy to mistype.
Should I lowercase utm_term too?
Optional - utm_term traditionally captures paid keywords, which Google Ads sometimes capitalises. Most teams lowercase everything for consistency, accepting the small loss of capitalisation fidelity.
/ Keep going

Pair with these.

Related free tools

UTM Parameter BuilderTag campaigns properly→Campaign Name GeneratorName campaigns in seconds→URL ShortenerShorten long URLs→Link Privacy CheckerWhere does a short link go?→

Related guides

Build a fresh UTM-tagged URLFREE TOOL→Generate a slug-safe campaign nameFREE TOOL→Shorten the validated URLFREE TOOL→Trace where the URL actually leadsFREE TOOL→

Track UTMs end-to-end with attr.so.

Every UTM on every click, captured automatically. No GA setup, no third-party scripts.

Start free See pricing
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