Inspect A/B Testing data with BigQuery

In addition to viewing A/B Testing experiment data in the Firebase console, you can inspect and analyze experiment data in BigQuery. While A/B Testing does not have a separate BigQuery table, experiment and variant memberships are stored on every Google Analytics event within the Analytics event tables.

The user properties that contain experiment information are of the form userProperty.key like "firebase_exp_%" or userProperty.key = "firebase_exp_01" where 01 is the experiment ID, and userProperty.value.string_value contains the (zero-based) index of the experiment variant.

You can use these experiment user properties to extract experiment data. This gives you the power to slice your experiment results in many different ways and independently verify the results of A/B Testing.

To get started, complete the following as described in this guide:

  1. Enable BigQuery export for Google Analytics in the Firebase console
  2. Access A/B Testing data using BigQuery
  3. Explore example queries

Enable BigQuery export for Google Analytics in the Firebase console

If you're on the Spark plan, you can use the BigQuery sandbox to access BigQuery at no cost, subject to Sandbox limits. See Pricing and the BigQuery sandbox for more information.

First, make sure that you're exporting your Analytics data to BigQuery:

  1. Open the Integrations tab, which you can access using > Project settings in the Firebase console.
  2. If you're already using BigQuery with other Firebase services, click Manage. Otherwise, click Link.
  3. Review About Linking Firebase to BigQuery, then click Next.
  4. In the Configure integration section, enable the Google Analytics toggle.
  5. Select a region and choose export settings.

  6. Click Link to BigQuery.

Depending on how you chose to export data, it may take up to a day for the tables to become available. For more information about exporting project data to BigQuery, see Export project data to BigQuery.

Access A/B Testing data in BigQuery

Before querying for data for a specific experiment, you'll want to obtain some or all of the following to use in your query:

  • Experiment ID: You can obtain this from the URL of the Experiment overview page. For example, if your URL looks like https://console.firebase.google.com/project/my_firebase_project/config/experiment/results/25, the experiment ID is 25.
  • Google Analytics property ID: This is your 9-digit Google Analytics property ID. You can find this within Google Analytics; it also appears in BigQuery when you expand your project name to show the name of your Google Analytics event table (project_name.analytics_000000000.events).
  • Experiment date: To compose a faster and more efficient query, it's good practice to limit your queries to the Google Analytics daily event table partitions that contain your experiment data—tables identified with a YYYYMMDD suffix. So, if your experiment ran from February 2, 2024 through May 2, 2024, you'd specify a _TABLE_SUFFIX between '20240202' AND '20240502'. For an example, see Select a specific experiment's values.
  • Event names: Typically, these correspond with your goal metrics that you configured in the experiment. For example, in_app_purchase events, ad_impression, or user_retention events.

After you gather the information you need to generate your query:

  1. Open BigQuery in the Google Cloud console.
  2. Select your project, then select Create SQL query.
  3. Add your query. For example queries to run, see Explore example queries.
  4. Click Run.

Query experiment data using the Firebase console's auto-generated query

If you're using the Blaze plan, the Experiment overview page provides a sample query that returns the experiment name, variants, event names, and the number of events for the experiment you're viewing.

To obtain and run the auto-generated query:

  1. From the Firebase console, open A/B Testing and select the A/B Testing experiment you want to query to open the Experiment overview.
  2. From the Options menu, beneath BigQuery integration, select Query experiment data. This opens your project in BigQuery within the Google Cloud console console and provides a basic query you can use to query your experiment data.

The following example shows a generated query for an experiment with three variants (including the baseline) named "Winter welcome experiment." It returns the active experiment name, variant name, unique event, and event count for each event. Note that the query builder doesn't specify your project name in the table name, as it opens directly within your project.

  /*
    This query is auto-generated by Firebase A/B Testing for your
    experiment "Winter welcome experiment".
    It demonstrates how you can get event counts for all Analytics
    events logged by each variant of this experiment's population.
  */
  SELECT
    'Winter welcome experiment' AS experimentName,
    CASE userProperty.value.string_value
      WHEN '0' THEN 'Baseline'
      WHEN '1' THEN 'Welcome message (1)'
      WHEN '2' THEN 'Welcome message (2)'
      END AS experimentVariant,
    event_name AS eventName,
    COUNT(*) AS count
  FROM
    `analytics_000000000.events_*`,
    UNNEST(user_properties) AS userProperty
  WHERE
    (_TABLE_SUFFIX BETWEEN '20240202' AND '20240502')
    AND userProperty.key = 'firebase_exp_25'
  GROUP BY
    experimentVariant, eventName

For additional query examples, proceed to Explore example queries.

Explore example queries

The following sections provide examples of queries you can use to extract A/B Testing experiment data from Google Analytics event tables.

Extract purchase and experiment standard deviation values from all experiments

You can use experiment results data to independently verify Firebase A/B Testing results. The following BigQuery SQL statement extracts experiment variants, the number of unique users in each variant, and sums total revenue from in_app_purchase and ecommerce_purchase events, and standard deviations for all experiments within the time range specified as the _TABLE_SUFFIX begin and end dates. You can use the data you obtain from this query with a statistical significance generator for one-tailed t-tests to verify that the results Firebase provides match your own analysis.

For more information about how A/B Testing calculates inference, see Interpret test results.

  /*
    This query returns all experiment variants, number of unique users,
    the average USD spent per user, and the standard deviation for all
    experiments within the date range specified for _TABLE_SUFFIX.
  */
  SELECT
    experimentNumber,
    experimentVariant,
    COUNT(*) AS unique_users,
    AVG(usd_value) AS usd_value_per_user,
    STDDEV(usd_value) AS std_dev
  FROM
    (
      SELECT
        userProperty.key AS experimentNumber,
        userProperty.value.string_value AS experimentVariant,
        user_pseudo_id,
        SUM(
          CASE
            WHEN event_name IN ('in_app_purchase', 'ecommerce_purchase')
              THEN event_value_in_usd
            ELSE 0
            END) AS usd_value
      FROM `PROJECT_NAME.analytics_ANALYTICS_ID.events_*`
      CROSS JOIN UNNEST(user_properties) AS userProperty
      WHERE
        userProperty.key LIKE 'firebase_exp_%'
        AND event_name IN ('in_app_purchase', 'ecommerce_purchase')
        AND (_TABLE_SUFFIX BETWEEN 'YYYYMMDD' AND 'YYYMMDD')
      GROUP BY 1, 2, 3
    )
  GROUP BY 1, 2
  ORDER BY 1, 2;

Select a specific experiment's values

The following example query illustrates how to obtain data for a specific experiment in BigQuery. This sample query returns the experiment name, variant names (including Baseline), event names, and event counts.

  SELECT
    'EXPERIMENT_NAME' AS experimentName,
    CASE userProperty.value.string_value
      WHEN '0' THEN 'Baseline'
      WHEN '1' THEN 'VARIANT_1_NAME'
      WHEN '2' THEN 'VARIANT_2_NAME'
      END AS experimentVariant,
    event_name AS eventName,
    COUNT(*) AS count
  FROM
    `analytics_ANALYTICS_PROPERTY.events_*`,
    UNNEST(user_properties) AS userProperty
  WHERE
    (_TABLE_SUFFIX BETWEEN 'YYYMMDD' AND 'YYYMMDD')
    AND userProperty.key = 'firebase_exp_EXPERIMENT_NUMBER'
  GROUP BY
    experimentVariant, eventName