# SEO A/B testing

Category: [Analytics & Measurement](https://seo-geo-glossary.com/en/glossary/category/analytics-measurement/) › [Reporting & conversions](https://seo-geo-glossary.com/en/glossary/category/analytics-measurement/reporting-conversions/) · Also known as: SEO split testing, SEO tests, split test

**SEO A/B testing** (also called SEO split testing) checks whether a change affects organic search performance. The term has two meanings in practice. A conversion A/B test shows different versions of one page to different visitors. An SEO test splits a group of similar pages, for example product pages, into a test group that gets the change and a control group that does not, then compares organic clicks over time. Search engines cannot be shown a "version B" per visitor, which is why SEO tests work on page groups. Google does not describe this method itself; it is a general approach from practice.

## How does an SEO test work?

1. Pick a set of pages with a similar template and enough organic traffic.
2. Split the set at random into a control group and a test group.
3. Apply the change to the test group only, for instance a new title pattern.
4. Compare the clicks of both groups against their pre-test trend.

The result is an estimate. Seasonality, updates and unrelated changes affect both groups, so only the difference between them carries information.

## What does Google say about tests with variants?

Google's guidance applies when visitors are sent to different versions of a page:

- **No cloaking.** Googlebot and users must see the same set of URLs. Showing different content to Googlebot is against Google's spam policies.
- **rel="canonical".** Variant URLs should point to the original with rel="canonical". Google prefers this over noindex because it matches the intent.
- **302, not 301.** Redirects to variants should be temporary (302) so the original URL stays in the index.
- **Limited duration.** Run the test only as long as needed, then remove variant URLs and testing scripts as soon as possible.

## Example

An online shop has 400 category pages. It places 200 of them in a test group and adds the product count to the title. After four weeks, the clicks of the test group are compared with the control group. This setup is a made-up example.

## Common mistakes

According to practitioner reports, these mistakes are common.

- **Treating a CRO tool like an SEO test.** Tools that swap content for visitors do not measure search effects.
- **Test and control groups that differ.** Pages with different traffic patterns make the comparison unreliable.
- **Leaving test code live.** Variants and scripts that stay after the test can look deceptive to Google.

## Related terms

- [Cloaking](https://seo-geo-glossary.com/en/glossary/cloaking/index.md)
- [Canonical tag](https://seo-geo-glossary.com/en/glossary/canonical-tag/index.md)
- [302 redirect](https://seo-geo-glossary.com/en/glossary/302-redirect/index.md)
- [Conversion rate optimization](https://seo-geo-glossary.com/en/glossary/conversion-rate-optimization/index.md)
- [Conversion rate](https://seo-geo-glossary.com/en/glossary/conversion-rate/index.md)

## Sources

- [Website testing and Google Search – Google Search Central](https://developers.google.com/search/docs/crawling-indexing/website-testing)

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Last updated: October 7, 2026
URL: https://seo-geo-glossary.com/en/glossary/seo-a-b-testing/