Google Analytics 4 has added a new dimension called Source Group, announced June 11, 2026 in the GA4 “What’s new” Help Center. It auto-collapses the fragmented traffic-source strings that have cluttered attribution reports for years, and it names ChatGPT and Perplexity among the platforms it consolidates.
The problem Source Group addresses is familiar to anyone who has eyeballed a GA4 source report. One social network can produce several raw string variants. Google’s own example: “facebook”, “fb”, and “Meta-facebook” each land as separate rows. Source Group rolls them into a single clean value, Facebook, without any tag changes or property configuration.
What is the GA4 Source Group dimension?
Source Group is a built-in GA4 dimension that automatically consolidates fragmented traffic-source strings into a single canonical value per platform. It is applied retroactively across historical data and requires no implementation work from property owners.
Which platforms get consolidated
Google’s documented example covers Facebook: the variants “facebook”, “fb”, and “Meta-facebook” collapse into a single Facebook value. The dimension applies the same consolidation logic across the platforms Google has named:
- TikTok
- Amazon
- YouTube
- Google Search
- Google Maps
- ChatGPT (OpenAI)
- Perplexity
The last two entries are the real news. Google now names AI-assistant sources, ChatGPT and Perplexity, among the platforms Source Group consolidates. That reflects where referral traffic has been drifting over the past year.
Retroactive, no setup, but not a full fix
Source Group is available immediately in standard reports, Explorations, and the advertising section. It applies retroactively: pull up any historical date range and the dimension populates. No tag changes, no custom channel group rules, no re-configuration.
“A single value for a given source is vital for performance and attribution analysis.”
— Google Analytics Help Center
That is true. It is also worth being precise about what Source Group does. It consolidates downstream, at the reporting layer, by mapping known source values to a canonical name. It only consolidates sources Google already recognizes, so clean upstream tagging still matters. Source Group is a convenience layer over your data, not a substitute for sending GA4 well-formed campaign parameters in the first place.
The durable answer is consistent upstream tagging. If every Facebook campaign URL carries the same utm_source and utm_medium values, the raw-string sprawl never starts, and Source Group becomes a convenience rather than a rescue. To build consistent UTM tags GA4 can group cleanly, fix the ambiguity at the source.
Where to find Source Group in GA4
The dimension is available now across three surfaces:
- Standard reports: add it as a secondary dimension in Traffic Acquisition or User Acquisition.
- Explorations: select “Source Group” from the dimensions panel in any free-form or funnel exploration.
- Advertising section: use it as a breakdown in conversion and attribution reports.
For teams building channel-performance comparisons, Source Group pairs well with the session-level source and medium logic described in the GA4 UTM tracking foundations pillar.
The ChatGPT and Perplexity inclusions signal something else. Google considers AI-driven referral traffic significant enough to name at the platform level, not just absorb into “other”. Whether that traffic converts at useful rates is a separate question, but now you can segment it cleanly and find out.
