The question isn't whether to run CRO tests. The question is which ones to run first. With limited testing bandwidth and a backlog that always outpaces capacity, prioritisation is the skill that separates CRO programmes that compound over time from those that spin their wheels.
High impact: test these first
- Value proposition clarity: the above-the-fold headline is often the single highest-leverage element on any page. Does it immediately communicate the specific benefit to a specific person? Vague headlines kill conversion rates. This is almost always the first test worth running.
- Call-to-action copy and placement: 'Submit' converts worse than 'Get my free quote.' Test specific, benefit-oriented CTA text first - it requires no design work and produces clear signal.
- Form length and friction: every field you remove from a form tends to increase completion rate. Ask only for what you absolutely need at this stage of the funnel.
- Trust signals: security badges, reviews, testimonials, and visible refund/returns policies directly reduce purchase anxiety. Their impact is consistently underestimated.
- Page speed: run a Google PageSpeed Insights test before anything else. A faster page is a useful technical hypothesis, but the conversion effect depends on the page, audience, and baseline.
Medium impact: work through these systematically
- Hero image or video (lifestyle vs product vs social proof imagery)
- Pricing presentation (anchoring, payment plans, per-unit vs total pricing)
- Navigation simplification (reducing exit routes on dedicated landing pages)
- Social proof placement (moving reviews closer to the primary CTA)
- Mobile layout and touch target sizes
Lower impact: do not start here
- Button colour (only matters when the button lacks contrast - fix that first, then stop)
- Font size and readability (important for accessibility, modest conversion impact)
- Stock photography vs. illustration style
The most common prioritisation mistake
Teams run button colour tests first because they're easy, not because they're impactful. Low-effort, low-impact tests are the enemy of a CRO programme. Your first 10 tests should all be high-risk, high-reward hypotheses - the ones that could fail but could also move the number by double digits.
Prioritisation frameworks
When your backlog has more ideas than bandwidth, score each hypothesis before starting. The two most widely used frameworks:
| Framework | Criteria | Best for |
|---|---|---|
| PIE | Potential × Importance × Ease (score 1–10 each) | General CRO backlogs, mixed team involvement |
| ICE | Impact × Confidence × Ease (score 1–10 each) | Product teams, data-heavy organisations |
Both frameworks produce a composite score per hypothesis. The highest scores get tested first. The real value isn't the score itself - it's the conversation the scoring process forces about what evidence each idea is actually based on.
Common prioritisation mistakes
CRO tools: a practical toolkit
| Category | Tool | Best For | Cost |
|---|---|---|---|
| Analytics | Google Analytics 4 | Funnel analysis, traffic behaviour | Free |
| Heatmaps / Recordings | Hotjar | Visual behaviour, exit surveys | Free–$$ |
| Heatmaps / Recordings | Microsoft Clarity | Session recordings (generous free tier) | Free |
| A/B Testing | VWO | Mid-market, strong analytics integration | $$ |
| A/B Testing | Optimizely | Enterprise, complex experimentation | $$ |
| A/B Testing | GA4 Experiments | Simple tests, Google ecosystem | Free |
| User Research | Hotjar Surveys | On-site surveys, exit intent | Free–$ |
| Usability Testing | Maze / UserTesting | Moderated and unmoderated tests | $–$$ |