GA4 BigQuery Export on the Free Tier: Setup, Limits and SQL

#01Sandbox or billing?

A low-cost pattern: start in the sandbox, and once you see value, enable billing and remove the default table expiration so history accumulates. Watch query costs by always filtering on _TABLE_SUFFIX and selecting only the columns you need.

#02How do you link it?

1. Create a Google Cloud project and enable the BigQuery API.
2. In GA4, Admin → Product links → BigQuery links → Link.
3. Choose the project and data location, select Daily (and Streaming only if you need it), and choose streams and any event exclusions.
4. Tables appear in a dataset called analytics_ followed by your property ID.

#03Copyable SQL

AI assistant referrers by page view, last month:

SELECT
  REGEXP_EXTRACT(
    (SELECT value.string_value FROM UNNEST(event_params) WHERE key = 'page_referrer'),
    r'^https?://([^/]+)') AS referrer_host,
  COUNT(*) AS page_views,
  COUNT(DISTINCT user_pseudo_id) AS users
FROM `your-project.analytics_123456789.events_*`
WHERE _TABLE_SUFFIX BETWEEN '20261001' AND '20261031'
  AND event_name = 'page_view'
  AND REGEXP_CONTAINS(
    (SELECT value.string_value FROM UNNEST(event_params) WHERE key = 'page_referrer'),
    r'chatgpt|openai|perplexity|claude|gemini|copilot|deepseek|grok')
GROUP BY referrer_host
ORDER BY page_views DESC;

Key events by last-click session source:

SELECT
  session_traffic_source_last_click.manual_campaign.source AS source,
  session_traffic_source_last_click.manual_campaign.medium AS medium,
  COUNTIF(event_name = 'generate_lead') AS leads
FROM `your-project.analytics_123456789.events_*`
WHERE _TABLE_SUFFIX BETWEEN '20261001' AND '20261031'
GROUP BY source, medium
ORDER BY leads DESC;

Replace the project, dataset and event name with your own. Field names come from Google's BigQuery Export schema page; check it if a column is missing in older tables.

Our view: even if nobody writes SQL yet, link BigQuery on day one. The history you start collecting today is the thing you can't buy later.

Next: Looker Studio reporting on GA4. Or return to the GA4 for Marketers track.

#04Common questions

Is GA4 BigQuery export free? The link is free for standard properties, and you can export to the BigQuery sandbox at no cost. Usage beyond sandbox or free-tier limits is charged by Google Cloud.

What is the daily export limit? Standard properties can export up to 1 million events per day in the daily export. Streaming export has no volume limit but costs extra.

Why did my old BigQuery tables disappear? In the BigQuery sandbox, tables and partitions expire automatically after 60 days. Enable billing and change the expiration to keep history.