About one in eight times. Rewriting the words on a button wins 12% of the time. For comparison, changing that same button's colour won 16% in our data — though on a much smaller sample, so do not read too much into the ordering.
A middling bet with a good payoff when it lands: the median winner moves +24.7%.
| Tests analysed | 250+ |
| Beat control | 12% |
| No measurable difference | 68% |
| Lost to control | 20% |
| Median lift when it won | +24.7% |
Typical winning range: +8.8% to +54.8% for the middle half of winners. Median traffic per variant was 1412 visitors. Most ran on homepages (120), product pages (48), lead capture pages (38).
The button's words change. Size, colour and position stay as they were. Change the colour too and you have two variables.
Adjacent categories, and how often they win: layout (15%), hero image (12%), styling (11%).
| page type | win rate | tests |
|---|---|---|
| homepages | 11% | 100+ |
| product pages | 6% | 48 tests |
| lead capture pages | 21% | 38 tests |
| landing pages | 10% | 31 tests |
Only page types with at least 30 CTA copy tests appear here.
The CTA button text changed from two action-oriented options to a single qualification check prompt.
The add to basket button text changed to quick add to basket, and the quantity field was hidden.
The donate link text changed to a more generic support phrase, and the CTA button background changed from its previous color to green.
The single quiz button was replaced with a quiz question and two choice buttons.
The CTA button text changed to “Create my FREE account” and now linked to the registration page, and a new paragraph was added above the existing text with a free-lessons, no-card, one-minute benefit line.
The CTA button text changed from the original wording to a Portuguese free-start phrase with an arrow symbol added at the end.
The read-more and read-less button text was changed from the original wording to Danish equivalents.
The subscribe button text changed to a membership call to action, and its width and spacing were adjusted.
The login and account labels and buttons were rewritten to promote a discount offer, the guest button was changed into a styled link, and the login pane was switched from stacked to side-by-side.
These are individual tests, not rules. Each ran on one site, with one audience, against one page we are not showing you. They are picked to be illustrative rather than sampled at random, and a change that won here can lose on your page for reasons none of this captures. Read them as prompts for what to test, not as findings to copy.
Button copy only reaches people who have already scrolled to the button and are deciding. That is a narrower audience than a hero or layout change reaches, which caps how much it can move.
| change type | win rate | tests |
|---|---|---|
| CTA colour | 16% | 32 |
| Layout | 15% | 351 |
| Form | 12% | 81 |
| CTA copy (this page) | 12% | 315 |
| Hero image | 12% | 160 |
| Price framing | 11% | 117 |
| Styling | 11% | 1414 |
| Split URL | 10% | 1165 |
| Headline | 8% | 918 |
| Social proof | 8% | 196 |
| Body copy | 6% | 337 |
A win rate only means as much as the thing being counted, so this is what these tests were actually optimising for.
| measured outcome | share of tests |
|---|---|
| Purchase / order complete | 25% |
| On-page click / engagement | 17% |
| Signup / registration | 17% |
| Lead / form submission | 13% |
Outcomes below 5% of the set are not listed, so these do not sum to 100. How the outcome was measured moves the win rate a lot — see the methodology.
These rates are not like-for-like. How often a test wins depends partly on what it chose to measure: a goal that records a soft signal — a click, a scroll — clears the bar more often than one that records a purchase. Across this data, tests measured against a proxy goal win 13%, against 9% for tests measured against a business outcome.
Categories differ a lot in that mix — proxy goals account for anywhere from 2% to 41% of a category's tests, and CTA copy tests sit at 41%.
Hold the metric fixed and the spread narrows sharply. Comparing only tests measured against a business outcome, CTA copy wins 11% (5–21%) rather than 12%, and the gap between the highest and lowest category falls from 9 points to 6 — at which point the intervals overlap and the categories are not statistically distinguishable.
So read the table as a description of what happened, not as a ranking of what works. If you want the comparison to mean something, compare categories that were measured the same way. The methodology page has the full breakdown.
The winners here do not settle it. Both specific and generic labels appear among them, and among the failures.
Layout carries a higher published rate, but the two are closer than that gap suggests once you account for what each was measured against. Test whichever you have a real hypothesis for.
This is every Mida account that ran a readable test — in-house marketers, founders, product teams, and agencies working on client sites. Nothing here is filtered by who ran the experiment or how experienced they are.
Low win rates are normal in experimentation, including at the top end. Microsoft's experimentation team, reporting on its own platform, found that only about one third of ideas improve the metric they were designed to improve — and that roughly another third actively hurt it. That is a dedicated experimentation organisation with research, prioritisation and review behind every test.
A mixed population like this one runs below that. The gap is roughly what disciplined practice buys you: ideas grounded in research rather than opinion, one variable at a time, and tests built so the result can actually be read.
So treat these as a general base rate, not a target. If you would rather not close that gap the slow way, find a CRO agency in the United States, the United Kingdom, the Netherlands or Australia — or browse every region.
A win is a variant that beat its control on that test's primary goal with a statistically significant result. Tests that never got enough traffic to say anything either way are excluded. The methodology has the full detail, including what these numbers cannot tell you.
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