Pattern #141: Square or Rounded Buttons

Pattern #141  Tested 5 timesFirst tested by Joachim Furuseth Recently tested by Andrey Andreev on May 23, 2026

Based on 5 Tests, Members See How Likely Version B Wins Or Loses And By How Much

LOSSES
-5
-4
-3
-2
-1
FLAT
+1
+2
+3
+4
+5
WINS

Measured by the sum of negative and positive tests.

A B
Square or Rounded Buttons (Variant A) Square or Rounded Buttons (Variant B)

Expected Median Effects Of B

X.X%

Progression

(5 tests)

-

Leads

-

Signups

-

Engagement

X.X%

Sales

(5 tests)

-

Revenue

-

Retention

-

Referrals

X.X%

ANY PRIMARY

(5 tests)

All 5 tests meta-analyzed: +X.X% combined effect (p-val X.XXXX)

93.1% of 90% cumulative power target at 1% MDE from 5 tests

90%
7.3% 11.5% 8.5% 22.1% 88.2%
Product 4 tests: X%
Global 1 test: X%

Tested on

Tests

Pattern #141: Square or Rounded Buttons
Was Tested On Online.metro-cc.ru by Andrey Andreev

Replaced

Isolated

Test # 649 on Online.metro-cc.... by Andrey AndreevAndrey Andreev May 23, 2026 Test link

Find Out How It Did With 9,171,836 Visitors

  • Measured by completed sales

  • Measured by adds to cart

  • XX.X% (XXX successes out of XXX,XXX visitors)
  • XX.X% (XXX successes out of XXX,XXX visitors)
  • XX.X% (XXX successes out of XXX,XXX visitors)
  • XX.X% (XXX successes out of XXX,XXX visitors)
Zoom In
Square or Rounded Buttons - Variant A A
Square or Rounded Buttons - Variant B B
Global
Statistical Power by Minimum Detectable Effect
35%0.5%
80%0.9%
88.2%1%
99.9%2%
99.9%5%
99.9%10%
99.9%15%
99.9%20%

In this experiment, square buttons were changed to rounded ones throughout the full site. Impact on adds-to-cart was measured.

Get Access To See The Test Results

The Same Pattern Was Also Tested Here

Replaced

Isolated

Test # 594 on Obs.no by Joachim FurusethJoachim Furuseth May 28, 2025 Test link

Find Out How It Did With 1,262,310 Visitors

  • Measured by adds to cart

  • Measured by completed sales

  • XX.X% (XXX successes out of XXX,XXX visitors)
  • XX.X% (XXX successes out of XXX,XXX visitors)
  • XX.X% (XXX successes out of XXX,XXX visitors)
  • XX.X% (XXX successes out of XXX,XXX visitors)
Zoom In
Square or Rounded Buttons - Variant A A
Square or Rounded Buttons - Variant B B
Product
Statistical Power by Minimum Detectable Effect
9%0.5%
22.1%1%
66.2%2%
80%2.4%
99.9%5%
99.9%10%
99.9%15%
99.9%20%

In this experiment, add-to-cart buttons on product details pages were rounded to 20px (variation), whereas the control had square buttons. Impact on adds to cart and purchases were measured.

Get Access To See The Test Results

Replaced

Isolated

Test # 593 on Obs.no by Joachim FurusethJoachim Furuseth May 27, 2025 Test link

Find Out How It Did With 694,658 Visitors

  • Measured by adds to cart

  • Measured by completed sales

  • XX.X% (XXX successes out of XXX,XXX visitors)
  • XX.X% (XXX successes out of XXX,XXX visitors)
  • XX.X% (XXX successes out of XXX,XXX visitors)
  • XX.X% (XXX successes out of XXX,XXX visitors)
Zoom In
Square or Rounded Buttons - Variant A A
Square or Rounded Buttons - Variant B B
Product
Statistical Power by Minimum Detectable Effect
5%0.5%
8.5%1%
21.7%2%
80%4.8%
83.2%5%
99.9%10%
99.9%15%
99.9%20%

In this experiment, add-to-cart buttons on product details pages were rounded to 20px (variation), whereas the control had square buttons. Impact on adds to cart and purchases were measured.

Get Access To See The Test Results

Replaced

Isolated

Test # 591 on Obsbygg.no by Joachim FurusethJoachim Furuseth May 25, 2025 Test link

Find Out How It Did With 925,560 Visitors

  • Measured by adds to cart

  • Measured by completed purchases

  • XX.X% (XXX successes out of XXX,XXX visitors)
  • XX.X% (XXX successes out of XXX,XXX visitors)
  • XX.X% (XXX successes out of XXX,XXX visitors)
  • XX.X% (XXX successes out of XXX,XXX visitors)
Zoom In
Square or Rounded Buttons - Variant A A
Square or Rounded Buttons - Variant B B
Product
Statistical Power by Minimum Detectable Effect
4%0.5%
7.3%1%
17%2%
70.3%5%
80%5.6%
99.9%10%
99.9%15%
99.9%20%

In this experiment, add-to-cart buttons on product details pages were rounded to 20px (variation), whereas the control had square buttons. Impact on adds to cart and purchases were measured.

Get Access To See The Test Results

Replaced

Isolated

Test # 592 on Obsbygg.no by Joachim FurusethJoachim Furuseth May 25, 2025 Test link

Find Out How It Did With 1,328,302 Visitors

  • Measured by adds to cart

  • Measured by completed sales

  • XX.X% (XXX successes out of XXX,XXX visitors)
  • XX.X% (XXX successes out of XXX,XXX visitors)
  • XX.X% (XXX successes out of XXX,XXX visitors)
  • XX.X% (XXX successes out of XXX,XXX visitors)
Zoom In
Square or Rounded Buttons - Variant A A
Square or Rounded Buttons - Variant B B
Product
Statistical Power by Minimum Detectable Effect
6%0.5%
11.5%1%
32.7%2%
80%3.7%
96.3%5%
99.9%10%
99.9%15%
99.9%20%

In this experiment, add-to-cart buttons on product details pages were rounded to 20px (variation), whereas the control had square buttons. Impact on adds to cart and purchases were measured.

Get Access To See The Test Results

For each pattern, we measure three key data points derived from related tests:

REPEATABILITY - this is a measure of how often a given pattern has generated a positive or negative effect. The higher this number, the more likely the pattern will continue to repeat.

SHALLOW MEDIAN - this is a median effect measured with low intent actions such as initiating the first step of a lengthier process

DEEP MEDIAN - this is derived from the highest intent metrics that we have for a given test such as fully completed signups or sales.