A/B testing API version 3

Differences between A/B testing APIs v2 and v3.

Changes compared to the A/B testing API version 2

• Time series endpoint

  Analyze how your chosen metrics evolve over time while the test runs.

  New in v3: GET /3/abtests/{id}/timeseries with date range and metric selection.

• Create A/B test

  Choose which metrics the experiment should measure, and add statistical controls for evaluation.

  • v2: create a test by naming it, defining its variants, and setting an end date.
  • v3: in addition, you explicitly select the metrics to analyze (for example, conversion rate) and can configure statistical options such as minimum detectable effect (MDE), and multiple-testing correction.

• Estimation endpoint

  Estimate required sample sizes and duration to detect your target effect.

  • v2: basic estimator.
  • v3: uses your selected metrics and desired effect size/MDE for more tailored estimates.

• Listing and retrieval

  Same operations with more flexible sorting/filtering and responses that include your selected metrics and evaluation settings.

  • Multi-variant testing
    • v2: mixed setups such as A/A/B are rejected. You must either use the same index for all variants (for example, A/A/A) or use distinct indices for all variants (for example, A/B/C). Mixed shapes fail with an invalid configuration error.
    • v3: supports mixed shapes (for example, A/A/B).

For details, see the API references:

• A/B testing API v2
• A/B testing API v3

When to migrate

Migrate if you need any of the following:

• Time series analysis of test metrics.
• Explicit metric selection per test.
• Minimum detectable effect (MDE), population filters, or multiple-testing correction.

If your v2 usage is stable and you don’t need these new features, you can keep using v2.

How to migrate

• Do this in all cases:

  • When creating a test, include the metrics to measure and any optional evaluation settings.
  • For planning, use the estimator with your desired effect size (MDE).
  • Use the time series endpoint if you need trends over time.

• If you call the REST API directly:

  Change base paths from /2/abtests to /3/abtests and adapt payloads.

• If you use an API client:

  • You need to use the latest major version of Algolia’s API clients.
  • If you’re using an older version, you need to upgrade first.
  • The A/B testing API version 2 is available in all supported versions.