Repeating the same key
Appending a second set of tags to an already-tagged URL creates ambiguous reporting. Replace the old set instead.
Privacy-safe repair
Build a corrected URL
Everything stays in this browser. Review the detected values, edit anything that is wrong, and create one canonical set of UTM tags. Existing non-UTM parameters and fragments stay intact.
Corrected link appears here
Run the check first, review the fields, then build the URL.
Rule set
What this UTM checker validates
- Required tags: nonblank
utm_source,utm_medium, andutm_campaign. A corrected tag must retain at least one ASCII letter or number after normalization. - Duplicate keys: repeated UTM keys, including casing variants such as
UTM_Source. - Casing and separators: uppercase values, spaces, or underscores that can split campaign reporting.
- Blank values: UTM keys that exist but contain no usable value.
- Encoding: malformed percent escapes or invalid UTF-8 in any query key or UTM value, plus values that look double encoded.
- Source/medium logic: a small deterministic set of combinations that deserve a human check.
Worked example
Worked UTM check example
Suppose an ad link arrives with duplicate source keys, mixed casing, underscores, and a double-encoded campaign value:
https://example.com/offer?ref=partner&UTM_Source=LinkedIn&utm_source=linkedin-ads&utm_medium=Paid_Social&utm_campaign=q3%2520launch- The checker flags the duplicate and noncanonical
UTM_Sourcekey. - It flags uppercase letters and underscores in
Paid_Social. - It flags
%2520because that usually represents a percent sign encoded twice. - The corrected workflow keeps
ref=partner, removes every old UTM variant, and creates one clean set of tags.
Corrected shape: https://example.com/offer?ref=partner&utm_source=linkedin-ads&utm_medium=paid-social&utm_campaign=q3-launch
Pre-publish review
Common UTM mistakes
Treating case as cosmetic
LinkedIn and linkedin can become separate values in reports. Pick one convention and enforce it.
Leaving keys blank
utm_campaign= is not useful campaign data. Add the intended value or remove the empty optional key.
Encoding the whole URL twice
Double encoding turns readable separators into strings such as %2520. Encode parameter values once.
Swapping source and medium
Source names where traffic came from; medium names the channel. For example, google / cpc is coherent while google / email deserves review.
Deleting unrelated parameters
Product, partner, or routing parameters may still matter. The corrected workflow preserves non-UTM query parameters.
FAQ
UTM Checker FAQ
Does the UTM checker send or store my URL?
No. The checker and corrected URL builder run locally in your browser. UTM Tools does not send the campaign URL or its values to a server or analytics event.
What happens when a URL has duplicate UTM parameters?
Different tools may select different values or preserve more than one. The checker flags duplicates, and the corrected URL workflow replaces every casing variant with one canonical key and value.
Should UTM values use lowercase letters and hyphens?
A consistent convention prevents one campaign from splitting into separate analytics rows. This checker recommends lowercase values with hyphens, while still showing the original values for review.
Can the checker fix a campaign URL?
Yes. Review or edit the detected fields, then build a corrected URL. Unrelated query parameters and the URL fragment are preserved; UTM keys are canonicalized and values are normalized locally.
Continue the campaign workflow
Define consistent names, build one GA4 campaign URL, scale it in bulk, then check the final link before publishing.
Build a GA4 campaign URL · Define campaign names · Scale in bulk · Check the result