Pinterest URL parameters do not override your feed or ad UTMs

If a link already carries UTM parameters, Pinterest's automatic ones will not replace them. Pinterest's URL parameters page says custom parameters you add, or edit, at the account, campaign or Performance+ ad group level do not override parameters that were added by hand in a product feed or in a destination URL field.

That matters for creative tests: a variant label set in a feed link keeps winning over the automatic utm_content, so two variants can end up reporting the same label.

Where a parameter can come from

Audit links before you queue variants

A short script catches links that already hold a utm_ key. Run it over your destination URLs before you render and name variants with Sume.

from urllib.parse import urlparse, parse_qs

links = [
    "https://example.com/shoes?utm_content=old",
    "https://example.com/shoes",
]
for url in links:
    keys = [k for k in parse_qs(urlparse(url).query) if k.startswith("utm_")]
    print(url, "has manual UTMs:" if keys else "clean", keys or "")

Next step

Decide which place owns the variant label, then render and name files to match, for example with one bulk run item per variant.