Data filters: internal and developer traffic

GA4 has exactly two kinds of data filter (Admin > Data filters), up to ten per property:

• Internal traffic: excludes events whose traffic_type parameter has a value you choose (default internal).
• Developer traffic: excludes events that carry debug_mode (that is, anything DebugView would show).

The traffic_type value is set by a rule, not by you in code: Admin > Data streams > stream > Configure tag settings > Define internal traffic. A rule matches IP addresses (single, ranges, CIDR) and sets traffic_type = internal. Because the match happens in the tag server-side, it works for GTM and gtag alike. You can create several rules with different values (internal, agency) and a filter per value.

Every filter has a state:

• Testing: nothing is excluded, but matching events get the dimension Test data filter name so you can see in a report what would be removed. Start here.
• Active: matching events are dropped before processing. Permanently. There is no way to recover filtered data later, not even in BigQuery (the export happens after filtering).
• Inactive: switched off.

A filter applies only from the moment it is active; it never removes historical data. Check the test dimension for a week, confirm the counts look like your team and not your customers, then activate.

What data filters cannot do: filter by hostname, country, bot signature or URL. For those, use report filters, custom reports with a baked-in filter, or segments in Explore. Known bots and spiders are excluded automatically and cannot be turned off.

Remote workers' home IPs change; for them, a GTM-set traffic_type based on a cookie, or simply the developer filter during QA, is more reliable than IP rules.