A/B Pre-test Calculator Chrome Plugin

One of the best A/B Pre-test Calculators, now in Plugin mode. Speero's A/B Pre-test Calculator helps you answer all important pre-test questions like:

What is the minimal detectable effect I can test for?
How long should I test for considering the effect?
What's the sample size?

Get it Free at Chrome WebStore

How to Use Speero's A/B Pre-test Calculator?

Enter data
Type in the number of weekly sessions or users, and conversions to see if your page has the capacity to test your ideas.
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OR

Get data automatically
Just sign in with Google Analytics and let Speero’s calculator get the results for you. *
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Pick events
You'll be able to pick conversion events straight from GA4 and which pages to calculate sessions and conversions from without even looking at your analytics. Or pick from dropdowns populated from your GA4 data.

* Speero's A/B Pre-test Calculator use and transfer of information received from Google APIs to any other app will adhere to Google API Services User Data Policy, including the Limited Use requirements.
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Speero’s A/B Pre-test Calculator is pre-defined for 2 variants (including control), confidence 95% and statical power of 80%.

Decide Instantly
Determine sample size, MDE, and test duration on the go.

Compare Multiple URLS
Filter By Page Path and compare pre-test data from multiple URLs.

Works from your tab
Our plugin connects with your GA4, letting you answer all your pre-test questions without leaving the tab.

Experimentation / CRO

Research & Strategy

Data and Analytics

A/B Pre-test Calculator Chrome Plugin

How to Use Speero's A/B Pre-test Calculator?