# A/B testing

CEFR B2 · Compound

Source: https://englishreference.com/word/a-b-testing
Updated: 2026-08-15

## Definition

a way to compare two versions of something, like a website or an email, to see which one people like more. You show version A to one group and version B to another to find the winner.

For teachers: a controlled experiment comparing two variants, A and B, to determine which performs better against a specific metric. Often used in digital marketing and software development to optimize user engagement or conversion rates.

## Examples

- We used A/B testing to choose the best button color.
- The marketing team is running an A/B testing campaign to see which subject line gets more clicks.
- By implementing rigorous A/B testing on the landing page, the developers identified specific user interface changes that significantly increased the overall conversion rate.

## Usage notes

- Typically functions as an uncountable noun or a compound modifier before another noun.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.