GA4 Adds Hostname Include Filters to Block Spam Traffic (September 2026)
GA4 and Tag Manager Product feature Completed Announced Rollout: Not stated by the platform Last verified
Quick answer
GA4 now offers Include data filters for hostnames, so a property can list which domains are allowed to send it event data. Until now only Exclude filters existed, and they needed manual upkeep as new spam sources appeared.
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What changed
- GA4 supports Include data filters for hostnames, letting you allowlist approved domains that may send event data to a property.
- Filtering was previously limited to Exclude filters, which needed ongoing manual updates to keep pace with new spam sources.
- Hostname Include filters are not applied to events sent through the Measurement Protocol, so that data stays unblocked.
- Include filters automatically block events with empty hostnames, which Google says usually point to spam or abnormal traffic.
Who is affected
- Any property receiving referral or hostname spam, and any property whose data is sent from several domains.
What to check this week
- List every domain that legitimately sends data to your property, including staging and payment domains, before you build an allowlist.
- Check whether any of your events arrive through the Measurement Protocol, since the Include filter will not apply to them.
Official sources
- What's new in Google AnalyticsGoogle Analytics Help · checked 8 October 2026
Related
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- Updated on 8 October 2026: Published automatically after verification against the official source.