The A/B test hypothesis template
One paragraph with six slots, written before anything gets built. Each slot is a trap for a different bad habit, and the last one is the one almost every template leaves out. Fill it in below and the sentence assembles as you type.
Write your hypothesis
Evidence first, because a hypothesis that opens with the change is a preference with grammar around it. Name the recording, the ticket volume, the funnel step or the earlier test.
What gets built. Specific enough that a developer could start without a meeting.
The size of the move you expect, not just its direction. A number here is what makes the test scoreable in a backlog.
A change that helps returning mobile buyers and hurts first-time desktop visitors nets to nothing. Say which group you meant before the segmentation argument starts.
Singular by design. Two primaries is zero primaries, and the second one exists so somebody can declare victory later.
The slot almost every template omits, and the one that converts a story into an experiment. Name the result that would make you abandon the belief rather than the execution.
Your hypothesis
Fill the slots above and the sentence assembles here, ready to copy into a ticket.
Three real rewrites
These are the shapes we see most often in client backlogs, alongside what they become once the template has been applied to them.
- Before
Test a sticky add-to-cart bar on mobile.
AfterBecause 34 session recordings show mobile visitors scrolling back up to find the buy button, we believe a sticky add-to-cart bar will lift add-to-cart rate by 4% for first-time mobile visitors, measured on add-to-cart rate. We are wrong if the lift is under 2% or checkout starts fall.
- Before
Our product pages need better copy.
AfterBecause 41% of pre-purchase support tickets ask about fit, we believe adding a fit summary above the fold will lift revenue per visitor by 3% for first-time visitors on apparel pages. We are wrong if fit tickets do not fall alongside it, which would mean the copy was not read.
- Before
Remove a checkout step.
AfterBecause analytics shows 22% of visitors abandoning at the account step, we believe offering guest checkout will lift checkout completion by 6% for new customers. We are wrong if completion rises while revenue per visitor does not, which would mean we moved abandonment rather than removed it.
Take it with you
The Word file is the same six slots as a form to fill in, plus the three rewrites for reference. Useful as a backlog attachment or a page in a build brief. No address needed.
Download Word (.docx)Generated from this page, so the two cannot disagree.
The PDF is the printable version, blank rather than filled in, since what you type above stays in your browser and never reaches us.
How we use it
The check that matters takes ten seconds. Read your hypothesis, then write down the result that would make you abandon the belief behind it rather than the execution of it. If you cannot name one, you do not have a hypothesis. You have a plan to gather evidence for something you have already decided.
The tell is easy to spot once you know it. A team with a real hypothesis says that if trust badges under the buy button do not lift add-to-cart rate by at least 3%, they stop treating badge placement as a lever. A team without one says it will try a different badge design, which is the same belief wearing a new outfit and a second fortnight of traffic. Both sound like learning. Only the first one can lose.
There is a second-order benefit that is easy to miss. A falsifiable hypothesis retires a whole class of ideas when it loses, not just the variation that was built. Kill badge placement properly and the six badge variations queued behind it leave the backlog with it, which is worth more than most winners: a programme is limited by how many questions it can ask per quarter, and the fastest way to ask better ones is to stop asking questions you have already answered.
Keep it to one paragraph, and keep it with the test for its whole life, from backlog row to build brief to readout slide. Store the version written before launch somewhere it cannot be quietly improved afterwards, because a hypothesis edited once the numbers are in stops being a prediction and becomes a caption. The reasoning behind each slot is in the full article on how to write an A/B test hypothesis.
Version
- v1.0 · 2026-08-07First published. Six slots and three rewrites, as written.
Questions about the template
It names a result that would make you abandon the belief behind the test rather than the execution of it. "If it does not win we will try a different design" is not falsifiable, because the belief survives every possible outcome. "If badges do not lift add-to-cart by 3% we stop treating badge placement as a lever" is, because there is a number that ends the argument.
Because two primaries is zero primaries. A second one exists so that somebody can declare victory later against whichever number happened to move, and a test with two ways to win has no way to lose. Pick the metric while you are writing, pick the one closest to money that your traffic can actually resolve, and write the guardrails down in the same breath.
No. The sentence assembles in your browser and stays there. Nothing is posted anywhere, nothing is stored, and closing the tab loses it, which is why the copy button is next to it. The only thing on this page that asks for an address is the PDF, and that sends you a blank template rather than anything you wrote.
Because three are real. They are rewrites of shapes that genuinely turn up in client backlogs, taken from the article this template comes from. Two more would have had to be made up to round the number out, and a template page arguing for evidence over preference is a poor place to start inventing examples.
Using this on your own site
The template is free to quote, screenshot and link to. A credit link is what keeps it findable for the next person searching for a hypothesis template rather than a lead magnet.
<p>A/B test hypothesis template by <a href="https://optyv.com/templates/ab-test-hypothesis">Optyv</a></p>No tracking in either snippet, and no nofollow on the link. It is a credit, not a beacon.
Or use the badge
For a backlog template, a team wiki or a process page, to show which shape your hypotheses are written to.
<a href="https://optyv.com/templates/ab-test-hypothesis"><img src="https://optyv.com/badge/hypothesis-template-used.svg" alt="Hypotheses written to the Optyv template" width="250" height="40"></a>Writing them is the cheap part
The discipline is holding the line when a test loses and the belief behind it wants a second fortnight. If you would rather someone else held the pen and the build capacity, that is what we do.
See how we build tests ↗