What Is Link-Level A/B Testing?
A/B testing is the practice of showing two or more variants of something to different groups of users and measuring which performs better. Most marketers think of A/B testing in terms of email subject lines, ad creative, or page designs.
Link-level A/B testing is simpler and more flexible: you create a single short link that randomly sends visitors to two or more destination URLs. Half go to version A of your landing page, half go to version B. Both groups click the same link and have no idea they're part of a test.
The main advantage of doing A/B testing at the link level is that you can change the test without touching your ads, emails, or social posts. The link stays the same; only where it points changes. You can run a test, learn something, and iterate — without pausing a live campaign or involving developers.
When Link A/B Testing Is the Right Tool
You have two landing pages already built and want real performance data. A split-test link sends equal traffic to both without any opinion-based guessing.
You're running paid ads and want to test destinations without duplicating campaigns. Changing the destination URL in an ad campaign often resets its learning period and can hurt performance. A split-test link lets you test landing pages without changing anything in the ad account.
You want to test across multiple traffic sources simultaneously. The same split-test link can appear in an email, a social post, and a paid ad. Each source sends traffic to the split, so you're testing with real, diverse traffic rather than isolated test traffic.
How to Set Up a Split-Test Link in TrimLynk
Step 1: When creating or editing a link, open the A/B testing panel in the advanced settings.
Step 2: Enter URL A (your control) and URL B (your challenger). You can add more than two variants.
Step 3: Set the traffic split. The default is 50/50, but for cautious testing, start with 80/20 — 80% to your known landing page, 20% to the new variant.
Step 4: Optionally configure an end condition. You can set a date when the test ends and all traffic routes to the winner, or leave it running until you manually choose.
Step 5: Monitor results in TrimLynk's analytics, which show click counts per variant separately.
What to Measure: Click-Through vs. Conversion
Link analytics tell you how many people clicked each variant. But clicks aren't the metric that matters — conversions are.
To measure conversions, you need tracking on the destination pages themselves. The workflow:
- Set up your split-test link (measures clicks per variant)
- Tag each destination URL with a unique
utm_contentparameter:utm_content=variant-aandutm_content=variant-b - Track goal completions in Google Analytics filtered by
utm_content
Now you have both click volume (from TrimLynk) and conversion rate (from Google Analytics). Divide conversions by clicks per variant to get a direct, apples-to-apples comparison.
Statistical Significance: When Is the Test Done?
The most common mistake in A/B testing is stopping too early because one variant looks better after a small sample. With small sample sizes, random variation can make a worse option appear to win.
As a practical guideline: wait until each variant has received at least 200-300 clicks before drawing conclusions. For high-stakes decisions, use a free statistical significance calculator and aim for 95% confidence before calling a winner.
If traffic is low, extend the test timeline rather than making decisions based on inconclusive data. A wrong conclusion sends all future traffic to the inferior page — which costs real conversions over time.
Acting on Your Results
When you have a clear winner, update the link to send all traffic to the winning destination. Document what you tested and what you found — a simple spreadsheet of past tests is genuinely useful for future decisions. If benefit-focused headlines beat feature-focused ones in this test, that learning applies beyond this one landing page.