9 Multivariate Testing Tools to Scale Agency Results

Managing multiple client accounts is already a balancing act. Proving your incremental value on top of that? Even harder.

For high-performing agencies, sustainable growth comes down to one thing: smarter testing. Multivariate testing tools make it possible to move beyond guesswork, uncover meaningful performance insights, and consistently improve results across accounts.

But here’s the problem.

You know testing drives performance — yet the tools often feel clunky, reporting becomes a manual time drain, and explaining statistical significance to clients turns into a full-time job. Instead of accelerating growth, your testing stack slows your team down.

The right platform should do more than just run experiments. It should streamline reporting, surface clear insights, and help your team operate more efficiently at scale. And the demand is only growing. The Multivariate Analysis Software market is projected to reach $6.8 billion by 2035 — signaling a clear shift toward data-driven optimization as the standard for modern agencies.

In this guide, we break down the best multivariate testing tools on the market — evaluated specifically through an agency lens.

What You'll Learn

• How to evaluate MVT tools based on agency-specific needs like scalability and reporting.
• Which platforms are built to handle multi-client workflows seamlessly.
• The key difference between website MVT and paid media MVT (and why your agency needs both).
• Bonus: A checklist for selling MVT services to your clients and proving ROI.

So what exactly are multivariate testing tools?

Unlike simple A/B tests, multivariate testing (MVT) platforms allow you to test multiple elements — headlines, images, CTAs, layouts — simultaneously. More importantly, they reveal how those variables interact with one another. The result? Deeper insights, stronger performance lifts, and data-backed outcomes that justify retainers and fuel real client growth.

Instead of guessing which single tweak might move the needle, MVT helps you understand the bigger picture — which combination of elements actually drives conversions. Maybe it’s not just the headline or just the image, but the way a benefit-driven headline pairs with a bold CTA and a specific visual style. That level of clarity means you’re no longer optimizing in silos. You’re building creative and landing experiences based on patterns, not hunches — and that’s where real, scalable performance starts to happen.

MVT for Agencies: More Than Just Finding a Winner

Alright, let's get one thing straight. Multivariate testing (MVT) isn't just A/B testing on steroids. While an A/B test compares two different versions of a page or ad (Version A vs. Version B), MVT tests multiple variables at once to see how they interact.

The formula is actually pretty simple: Total Variations = (Variations of Element 1) x (Variations of Element 2) x (Variations of Element 3)...

So, if you're testing 3 headlines, 3 images, and 2 CTAs, you're not running 8 separate tests. You're running one test with 18 different combinations (3 x 3 x 2). This is where you find the real magic—that unexpected combination that delivers a massive lift.

But here’s why this really matters for you as an agency. Basic testing is now table stakes. According to one report, about 77% of firms globally conduct A/B testing on their websites. Your clients expect it.

To stand out and justify your fees, you need to bring a more sophisticated approach. MVT is that approach. It shows you’re not just guessing; you’re engineering results. With 71% of companies running two or more tests each month, you need a process and a platform that can keep up without burning out your team.

How to Choose an MVT Tool: The 5-Point Agency Scorecard

Not all testing tools are created equal, especially when you’re running an agency. A platform that’s great for a single in-house brand can be a total nightmare for managing ten clients.

So, we created a 5-point scorecard to help you evaluate tools through a proper agency lens.

1. Multi-Client Management: This is non-negotiable. Can you easily switch between client accounts? Is data properly isolated to prevent embarrassing mix-ups? Does it offer user roles so you can give junior team members or even clients limited access without handing over the keys to the kingdom?
2. Reporting & Analytics: How quickly can you pull a client-facing report that looks professional and actually tells a story? Does it just show test results, or can it integrate with ad platforms like Meta and Google to show the impact on ROAS and CPA? The less time you spend in spreadsheets, the more time you have for strategy.
3. Team Efficiency: Can a new team member get up and running quickly, or does it require a Ph.D. in statistics? Look for features like visual editors, AI-powered suggestions, and automated analysis. Your goal is to make your entire team smarter and faster, not just your head of analytics.
4. Statistical Model: Don't let your eyes glaze over! This is important. Does the tool use a Bayesian or Frequentist model? Bayesian models can often declare winners faster and with less traffic, which is a huge plus for clients with smaller budgets.
5. Pricing & ROI: Is the pricing model built for agencies? Does it scale predictably as you add more clients, or will you get hit with a massive bill after signing one new account? The tool should pay for itself through improved client results and saved billable hours.

Pro Tip: When evaluating statistical models, ask yourself: "How easily can I explain this to my client?" A tool that translates complex stats into a simple "Probability to be best" or "Chance to win" percentage is worth its weight in gold. It helps you communicate value without a statistics lecture.

The 9 Best Multivariate Testing Tools for Marketing Agencies

We’ve applied our agency scorecard to the top tools on the market. Here’s our breakdown, starting with a powerful platform designed for agencies focused on scaling paid media.

1. Madgicx: Best for Paid Media Multivariate Testing & Reporting

• Agency Focus: Madgicx is built from the ground up for agencies and performance marketers managing ad spend on Meta. While most MVT tools focus on your website, Madgicx lives where your ad budget is spent, streamlining the incredibly complex process of testing ad creatives, audiences, and placements.
• Key Differentiator: Its true power for agencies lies in combining AI-powered ad creation with intelligent reporting and analysis. The AI Marketer helps you generate and launch structured ad variations built for performance, while the One-Click Report and Business Dashboard eliminate the client reporting headache by consolidating all ad platform data into a single, beautiful, shareable dashboard. And with AI Chat acting as your 24/7 on-demand analyst, anyone on your team can ask questions and get instant, data-backed answers.
• Best For: Performance marketing agencies that want to scale ad optimization, automate client reporting, and make every team member more effective.
• Free trial available here.

2. VWO (Visual Website Optimizer): Best All-in-One CRO Platform for Agencies

• Agency Focus: VWO is a powerhouse for conversion rate optimization (CRO). Its agency plans are well-structured for managing multiple clients, and the platform includes MVT, A/B testing, heatmaps, session recordings, and surveys.
• Key Differentiator: It allows you to pair quantitative data (like an MVT test result) with qualitative data (like a heatmap). This helps you build a complete narrative for your clients, explaining not just what won, but why.
• Best For: Full-service digital agencies and CRO specialists who need a comprehensive toolkit for website optimization.

3. Convert.com: Best for Privacy-Conscious & Mid-Sized Agencies

• Agency Focus: Convert.com is a favorite among agencies for its transparent, traffic-based pricing and robust multi-client features. It delivers enterprise-level power without the opaque "contact us for a demo" pricing.
• Key Differentiator: A strong commitment to privacy. It's fully GDPR/CCPA compliant and engineered to be flicker-free, which are major selling points for clients, especially those in Europe or privacy-sensitive industries.
• Best For: Agencies with a European client base or those who make data privacy a core part of their value proposition.

4. Statsig: Best for Agencies with Developer-Heavy Clients

• Agency Focus: If your clients are primarily tech companies or SaaS platforms, Statsig speaks their language. It's a developer-first experimentation platform that goes beyond marketing to test features, algorithms, and product changes.
• Key Differentiator: It's "warehouse-native," meaning it can run experiments directly on a client's data warehouse (like Snowflake or BigQuery). This offers maximum data security and allows for incredibly complex testing.
• Best For: Technical marketing agencies or those who work closely with their clients' product and engineering teams.

5. Optimizely: Best for Enterprise-Level Clients

• Agency Focus: Optimizely is the 800-pound gorilla in the experimentation space. If your agency serves Fortune 500 clients, there's a good chance they're already using it or will expect you to be proficient with it.
• Key Differentiator: Its powerful "Stats Engine" and deep integrations with other enterprise software like Salesforce and Adobe make it the central nervous system for experimentation in large organizations.
• Best For: Agencies with a portfolio of large, enterprise-level clients who demand a market-leading solution.

6. AB Tasty: Best for Speed and AI-Powered Personalization

• Agency Focus: AB Tasty offers a solid MVT platform with a focus on speed and ease of use. It also has strong personalization features, allowing agencies to go beyond testing and start delivering unique experiences to different audience segments.
• Key Differentiator: AI-driven personalization and audience segmentation help agencies deliver more advanced strategies to clients.
• Best For: E-commerce focused agencies that want to quickly implement testing and personalization for clients.

7. GrowthBook: Best Open-Source Option for Full Control

• Agency Focus: For agencies with development resources, GrowthBook offers a powerful, open-source alternative. You host it yourself, giving you complete control over the data and functionality.
• Key Differentiator: It's free (if you self-host) and highly extensible. It combines feature flagging with A/B testing, making it a great choice for SaaS clients.
• Best For: Technically-savvy agencies that want to build a custom testing solution without licensing fees.

8. Zoho PageSense: Best for Agencies on a Budget

• Agency Focus: As part of the broader Zoho ecosystem, PageSense offers a surprisingly robust set of CRO tools—including MVT—at an extremely competitive price point.
• Key Differentiator: The value. It provides many of the features of more expensive platforms for a fraction of the cost, making it a great entry point for agencies just starting to offer CRO services.
• Best For: Small agencies, freelancers, or those looking for one of the most affordable business tools for marketing.

9. Userpilot: Best for SaaS Client User Onboarding Tests

• Agency Focus: While not a traditional MVT tool for websites, Userpilot is essential for agencies with SaaS clients. It allows you to test and personalize the in-app user experience, from onboarding flows to feature announcements.
• Key Differentiator: It focuses exclusively on the in-product experience, a critical growth lever for any SaaS business.
• Best For: Agencies specializing in SaaS marketing and product-led growth.

Common MVT Pitfalls for Agencies (And How to Avoid Them)

Rolling out a testing program is exciting, but it's easy to stumble. We've seen it happen. Here are a few common traps agencies fall into and how you can sidestep them.

• The "Not Enough Traffic" Problem: Your new client is eager to test, but their site traffic is too low for a 24-variation MVT test to reach statistical significance this century.
  
  • How to Avoid It: Don't over-complicate it. Start with a simple A/B/n test on their highest-impact element. For paid ads, use a tool like Madgicx that lets you test creatives and audiences even with smaller budgets.
• The Reporting Black Hole: The test is done, you found a winner, but now you have to spend four hours cobbling together a report in Google Slides that your client barely understands.
  
  • How to Avoid It: This is a tool problem. Use a platform with built-in, automated reporting. Our One-Click Report was designed specifically to solve this, turning hours of work into a streamlined process.
• Losing the "Why": The test shows that the orange button beat the blue button by 15%. The client asks why. You shrug.
  
  • How to Avoid It: Pair your quantitative MVT data with qualitative insights. Use heatmaps (VWO) to see where users hovered. For ads, use creative analysis (Madgicx) to see which visual elements are driving performance. The "why" is what makes you a strategist, not just a technician.
• Scope Creep: Your "quick test" for a client has spiraled into a never-ending series of requests, derailing your team and blowing past your retainer hours.
  
  • How to Avoid It: Create a structured "testing roadmap" for each client at the start of every quarter. Define the hypotheses, prioritize tests by potential impact, and get client sign-off. This manages expectations and demonstrates a clear, strategic plan.

Pro Tip: Use your testing roadmap as a value-add in your quarterly business reviews (QBRs). Presenting a clear plan for the next 90 days shows proactive strategic thinking and helps justify your retainer. For a deeper dive, check out our guide on ad testing.

Frequently Asked Questions (FAQ)

How do I sell multivariate testing services to my clients?

Focus on the ROI. Don't sell "multivariate testing"; sell "maximizing the value of your existing traffic" or "a data-driven system for improving ad performance." Frame it as a standard practice for growth. Mentioning that 85% of businesses prioritize testing their CTA triggers shows you’re bringing them an industry-best practice to make their budget work harder.

What's the minimum traffic needed for a multivariate test?

It depends on your conversion rate, the number of variations, and your tool's statistical model. The good news is that tools with Bayesian statistics engines can often declare a winner with less traffic. The key is to start with tests on your highest-traffic pages or ad campaigns to get results faster.

Can I run MVT for a client with a small budget?

Absolutely. For a small website, run a simpler test with fewer variations (e.g., 2 headlines x 2 images = 4 combinations). But the best place to start is often with their paid social media advertising. With a platform like Madgicx, you can run sophisticated creative testing on Meta ads and get clear results even with a modest spend.

How is MVT different from the A/B testing I do in Google Ads or Meta Ads?

The native tools are great for simple A/B tests (one audience vs. another). MVT platforms take it a step further by testing the interaction between components. For example, an MVT approach can tell you if Headline A works best with Image X, while Headline B is a winner with Image Y—finding those winning combinations that simple A/B testing misses.

Build Your Agency's Testing Engine

Choosing the right multivariate testing tool isn't just about picking software with the most features. It's a strategic decision that directly impacts your agency's efficiency, scalability, and client retention.

The goal is to build a tech stack that saves you time and makes your clients money. For optimizing ad spend, a platform like Madgicx is designed to streamline complex ad testing and simplify reporting, freeing up your team to focus on strategy. For deep website CRO, tools like VWO or Convert.com provide the power you need.

The best way to start? Don't overthink it. Audit your current client roster, identify one high-impact test you can run next month, and see for yourself how a smarter testing platform can work for your business. You've got this.

Start your free Madgicx trial.