Find the offer that earns more per visitor.
Experiment Engine by Log Studio Lab runs A/B tests on discounts, shipping offers, content and landing pages, and compares the versions by profit, not just conversion. It is its own Shopify app with its own plans, trial and bill.
Experiment Engine by Log Studio Lab is not on the Shopify App Store yet. Freebies Engine works on its own in the meantime; ask us to tell you when Testing opens.
Experiment Engine by Log Studio Lab
Find the version that earns more per visitor. Run tests on prices, discounts, shipping offers, page templates, checkout and content, with up to five versions at a time. Experiment Engine is a separate Shopify app that runs in your Log Studio Lab account and is billed by Shopify on its own.
| Variant | Visitors | Conversion | Profit / visitor |
|---|---|---|---|
| Control | 4,210 | 3.1% | $1.84 |
| Free tote over $75 | 4,188 | 3.6% | $2.26 |
Test what shoppers actually see.
Example · Discounts test
Compared by profit per visitor.
Split traffic, then trust the result.
- Choose what share of traffic enters the test, and split it between a control and variants.
- Each visitor keeps the same variant every time they come back.
- Results say how sure they are, and a test with too little data says so instead of picking a winner.
- Mutual exclusion groups keep two tests from touching the same visitor.
Choose who enters the test.
- Everyone, or only new visitors, only returning visitors, or visitors from some markets.
- Narrow it to a campaign (UTM), customer tags or specific pages.
- Schedule a start and an end in store time.
Profit per visitor, not just conversion.
- Product cost, taken from Shopify or imported from a spreadsheet.
- Your real shipping cost and payment fees.
- One number to compare: profit per visitor.
Profit tracking starts on Experiment Engine Growth.
What the app does for you.
What you can test
Price: change what shoppers pay for a product, in the cart and at checkout, without editing the price in Shopify.
Templates and content: try a different product page layout, headline, image or button.
Checkout: test content and trust blocks in checkout (Shopify Plus stores).
Discounts and shipping: compare a percentage off with free shipping, or two thresholds.
Offers: test a Freebies Engine offer against another one.
Up to five versions, and a baseline
Test your original against up to four changes at once. Hold back a share of visitors as a baseline who never see any change, so you can tell whether a change helped or whether the audience was just having a good week.
Test several changes at once (multivariate)
What it is. Change two or three things on a page together, such as the headline, the image and the button text, and let the app try the combinations, up to eight in all.
Why it helps. You see which single change matters most and which combination wins, in one test instead of three in a row.
Good to know. It works for content tests, and it needs more visitors than a simple A/B test, because the traffic is split across more versions. Start with one change if your store has modest traffic.
Send more traffic to the leader (optional, off by default)
What it is. By default every test uses a fixed split, such as 50/50. If you prefer, switch a test to “send more traffic to the leader”: the app gradually sends more new shoppers to the version that is winning. Every version keeps at least 10% of traffic, so the test keeps learning.
Why it helps. Fewer sales are lost to a weaker version while the test runs. It suits a short sale or a busy season, when earning during the test matters more than a clean answer.
Good to know. It is not a controlled comparison, because the split changes as the test goes. If you want a clean, defensible answer, keep the fixed split.
Measure what you care about
Add your own events, such as a quiz finished or a sample requested, and use them as the goal. Results show profit per visitor after product cost, shipping and fees.
Safe for Google Shopping and ads
Price tests never change the price in Shopify, so your Google Merchant Center and Meta feeds keep sending the original. Search and ad crawlers, including Googlebot and the shopping and ads crawlers, are never put in a test. They see your original page and price.
Privacy built in
The app waits for your shopper's consent before it sends assignment events to your data layer. Shoppers who have not accepted analytics see the original and are not tracked. Data requests and deletions from Shopify are handled for you.
Apply the winner, and keep measuring
When a template, price or checkout version wins, apply it to everyone from the results page, with the steps to make it permanent in your theme. After you apply it, a panel compares the version during the test with the same version since the rollout, and says plainly that it is not a controlled test. A winning discount is created for you; to run an offer or discount every day, build it in Freebies Engine.
Share and get alerted
Send a read-only results link to a teammate, a client or an agency. Links expire, can be revoked at any time, and show results only. Get an alert by email or in Slack when a test needs attention.
Start from a playbook
Not sure what to test first? Start from a playbook: a ready-made test for a common goal, such as a free-shipping threshold or a price change. Filter your tests by goal to see what you have already tried.
Connect your analytics
GA4: every shopper who enters a test is pushed to your data layer with the test and version, so you can build an audience in GA4. The app can also send assignments to GA4 directly.
Klaviyo: send an “Experiment Viewed” event to Klaviyo so you can segment by version.
Results API: a read-only API and token give your scripts, dashboards and agency reports the same numbers the results page shows.
Session recordings: tag Microsoft Clarity or Hotjar recordings with the version, so you can watch how shoppers use each one.
Check the price on every page
Prices drawn by other apps, such as quick view, search or recommendations, can show the wrong number. Before a price test starts, a readiness check lists the places we cannot cover and what to do about them.
Built so a test can't hurt the store.
Experiment Engine measures. Freebies Engine runs.
Once a test shows a winner, apply it. For a template, price or checkout test, that ships the winning version to everyone from the results page. To run an offer or discount every day with a stacking order and schedules in store time, build it in Freebies Engine from a template. You can use either product on its own.
Experiment Engine plans
Prices in USD, billed through Shopify.
Prove which offer earns more.
Start with one test on one page. Testing tells you when the result is real, and when it is only luck.