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Conversion rate optimization tools
Conversion rate optimization tools help you find why visitors do not convert and prove which changes fix it. This guide sorts CRO tools by the question each one answers, describes each tool from its vendor's own site, and shows which few you need at each stage. No prices, ratings or affiliate links.
Short answer
Conversion rate optimization tools, or CRO tools, are software that helps you understand why website visitors leave without converting and test changes that get more of them to act. The main types are analytics, heatmaps and session recordings, A/B testing, surveys, user testing, form analytics, page speed tools and landing page builders, and each answers a different question.
- Set up analytics you trust first, because every other decision rests on its numbers.
- Add surveys and form analytics when you need to know why, and an A/B testing tool once you have evidence and enough traffic.
- Buying a testing tool first is the most common mistake.
- Google Optimize has been shut down, so choose a current A/B testing tool.
- Few CRO tools yet check whether AI agents can use your pages.
What are conversion rate optimization tools?
Conversion rate optimization tools, or CRO tools, are software that helps you understand why website visitors leave without buying, signing up or getting in touch, and test changes that get more of them to act. They collect evidence, such as analytics, heatmaps, recordings and survey answers, and they run experiments that prove what works.
No tool does conversion rate optimization for you. Tools answer questions; the work is asking the right ones, turning the answers into hypotheses, and reading test results honestly. That is why this guide is organized by the question each tool answers rather than as a ranked list.
Types of CRO tools, and the question each answers
There are eight main types of CRO tools: analytics, heatmaps and session recordings, A/B testing, surveys and feedback, user testing, form analytics, page speed tools and landing page builders. Each answers a different question. The table lists the 22 tools covered on this page by type.
| Type | Question it answers | Tools on this page |
|---|---|---|
| Analytics tools | Where do visitors come from, and where do they leave? | Google Analytics 4, Mixpanel, Amplitude Analytics, PostHog |
| Heatmap and session recording tools | What do visitors do on the page? | Microsoft Clarity, Hotjar, Crazy Egg, Mouseflow |
| A/B testing tools | Does the change actually work? | Wingify (VWO, AB Tasty), Optimizely, Convert, GrowthBook |
| Survey and feedback tools | Why did visitors leave or hesitate? | Qualaroo, Hotjar, Lucky Orange |
| User testing tools | Can a real person complete the task? | Lyssna, UserTesting, Maze |
| Form analytics tools | Which form field makes people give up? | Zuko, Mouseflow, Zoho PageSense |
| Page speed tools | Is the page fast and stable on a phone? | PageSpeed Insights |
| Landing page builders | Can marketers build and test pages without a developer? | Unbounce, Instapage |
Analytics tools: where do visitors come from, and where do they leave?
Analytics tools are the first CRO tool to set up, because every other decision rests on their numbers. They show which pages and traffic sources convert, and where in the funnel people leave. Check that conversions in analytics match real orders or leads before you trust any report.
Google Analytics 4
Google's event-based analytics for websites and apps.
- Event-based data from websites and apps in one property
- Privacy controls, including cookieless measurement and modeling
- Predictive capabilities and integrations with Google's ad platforms
Free plan: Stated as free of charge. Vendor site
Mixpanel
Product analytics with funnels, journeys, session replay and experiments.
- Funnels, drop-off and user journey reports
- Session replay and heatmaps
- Experiments and metric trees
Free plan: Free forever plan stated. Vendor site
Amplitude Analytics
Product analytics for conversion, retention and feature engagement.
- Funnel comparison and behavior correlation
- Anomaly alerts and root cause analysis
- Session replay, heatmaps, in-product guides and surveys
Free plan: Free plan stated. Vendor site
PostHog
An open source product platform that combines analytics, experiments, feature flags, session replay and heatmaps.
- A/B, A/B/n, holdout and redirect tests, built on feature flags
- Bayesian or frequentist analysis
- Heatmaps, clickmaps and scrollmaps, with rage and dead click detection
- Session replay on web and in iOS and Android apps
Free plan: Free tier stated, open source. Vendor site
Heatmap and session recording tools: what do visitors do on the page?
Heatmap and session recording tools show what visitors do on a page: where they click, how far they scroll and where they hesitate. They turn a leaking page from the analytics into a specific problem you can fix or test.
Microsoft Clarity
A free behavior analytics tool with heatmaps and session recordings.
- Click and scroll heatmaps
- Session recordings with highlights and AI summaries
- A mobile app SDK and a Google Analytics integration
Free plan: Free forever stated, no traffic limits. Vendor site
Hotjar (now part of Contentsquare)
Hotjar is now part of Contentsquare. Its site says new Hotjar accounts can no longer be created, and new users sign up to Contentsquare instead.
- Heatmaps and session recordings
- Surveys and user interviews
- Funnels, error and performance monitoring, and AI summaries
Free plan: Free plan stated, through Contentsquare. Vendor site
Crazy Egg
A website analytics tool known for its heatmaps, with recordings, surveys and A/B testing.
- Five map views: heatmap, scrollmap, confetti, overlay and list
- Session recordings with AI analysis, surveys and error tracking
- A/B tests built with a visual editor or URL redirects
- Heatmaps and recordings for each test variant, and a GA4 integration
Free plan: Free plan stated. Vendor site
Mouseflow
Session recording and heatmap software with funnels, form analytics and feedback.
- Heatmaps compared across periods, devices and segments
- Session recordings with rage click capture and friction detection
- User journeys, conversion funnels, form analytics and surveys
Free plan: Free plan stated. Vendor site
A/B testing tools: does the change actually work?
A/B testing tools prove whether a change works by showing it to some visitors and not others, then comparing results. They are the step that separates CRO from guessing, and they need enough traffic to reach a reliable answer.
Wingify Experimentation (VWO and AB Tasty)
VWO and AB Tasty have merged under the Wingify name, and VWO's testing pages now lead to Wingify Experimentation.
- A/B, multivariate, split URL and multi-page tests from a no-code editor
- Server-side experiments and feature flags, plus mobile app testing
- An AI assistant that helps plan, build and summarize experiments
- Test reports alongside heatmaps and session recordings
Free plan: Free trial stated, no free plan. Vendor site
Optimizely Experimentation and Feature Management
Optimizely's web testing product (formerly Web Experimentation) and its feature flag product (formerly Feature Experimentation) sit inside a wider platform that also covers content management, commerce and personalization.
- Visual editor for web tests, with server-side control for deeper tests
- Multivariate tests and bandits as well as A/B tests
- Feature flags with targeted and progressive rollouts and a kill switch
- SDKs for back end, mobile and edge, and personalization
Free plan: not stated on the vendor's site. Vendor site
Convert Experiences
A testing platform for web teams with client-side and full-stack testing and a built-in insights module.
- A/B, split URL, multivariate and multipage tests, including price tests
- Full-stack experiments with SDKs and an edge worker
- Heatmaps and session recordings included in every plan
- Visual editor plus code editors, and personalization
Free plan: Free trial stated, no free plan. Vendor site
GrowthBook
An open source experimentation and feature flag platform that can be self-hosted.
- Open source, with a self-hosted option
- Warehouse-native analysis with Bayesian and sequential statistics
- Feature flags with ramp schedules and automatic rollbacks
- A visual editor and SDKs for server, client, mobile and edge
Free plan: Free tier stated, open source. Vendor site
Survey and feedback tools: why did visitors leave or hesitate?
Survey and feedback tools ask visitors directly what stopped them, in their own words. A one-question poll on a key page, or a short survey after purchase, often explains what analytics and heatmaps only show.
Qualaroo
On-site and in-app micro-surveys that ask visitors questions in context.
- Targeted micro-surveys on websites and in apps, including exit-intent surveys
- Question branching and sentiment analysis
- iOS and Android SDKs
Free plan: Free plan stated for startups and small businesses. Vendor site
Hotjar (now part of Contentsquare)
Hotjar is now part of Contentsquare. Its site says new Hotjar accounts can no longer be created, and new users sign up to Contentsquare instead.
- Heatmaps and session recordings
- Surveys and user interviews
- Funnels, error and performance monitoring, and AI summaries
Free plan: Free plan stated, through Contentsquare. Vendor site
Lucky Orange
A conversion toolkit with heatmaps, recordings, live chat and surveys.
- Click, scroll and move heatmaps, including dropdowns and pop-ups
- Session recordings, conversion funnels and form analytics
- Surveys, announcements and live chat
Free plan: not stated on the vendor's site. Vendor site
User testing tools: can a real person complete the task?
User testing tools let you watch real people try to complete a task on your site or prototype, often while thinking aloud. They find usability problems before you have traffic to test, and they work on designs that are not live yet.
Lyssna (formerly UsabilityHub)
A user research platform for quick design tests, surveys and interviews.
- First click, five second, preference, prototype and tree tests
- Card sorting, live website testing, surveys and interviews
- A research panel to recruit participants
Free plan: Free plan stated. Vendor site
UserTesting
Video-based feedback from real people using your site, app or prototype.
- Recorded sessions of participants thinking aloud
- Participant recruiting and scheduling
- AI-assisted analysis and highlight reels
Free plan: not stated on the vendor's site. Vendor site
Maze
A user research platform for prototype, website and mobile tests.
- Prototype, live website and mobile testing
- Card sorting, tree testing and surveys
- Moderated interviews and automated reports
Free plan: not stated on the vendor's site. Vendor site
Form analytics tools: which form field makes people give up?
Form analytics tools show which fields people hesitate on, correct, or abandon at. For lead generation sites and checkouts, the form is the conversion, so field-level data is often the most useful CRO evidence you can get.
Zuko
Form analytics software. Its site says Zuko is the successor to Formisimo, which Convertica used in the Empire Flippers case study.
- Form-level abandonment and field-level analytics
- Session replay of form journeys and Shopify checkout analytics
- An Agent Score for how AI agents fail on forms
Free plan: not stated on the vendor's site. Vendor site
Mouseflow
Session recording and heatmap software with funnels, form analytics and feedback.
- Heatmaps compared across periods, devices and segments
- Session recordings with rage click capture and friction detection
- User journeys, conversion funnels, form analytics and surveys
Free plan: Free plan stated. Vendor site
Zoho PageSense
A conversion tool that combines testing, heatmaps, session recording, funnels and form analytics.
- A/B, split URL and multivariate tests with a visual and code editor
- Heatmaps and session recordings with AI summaries
- Funnel and form analytics
- Personalization, full-stack SDKs and mobile A/B testing
Free plan: Forever free plan stated. Vendor site
Page speed tools: is the page fast and stable on a phone?
Page speed tools measure how fast a page loads and how stable it is while loading, for real users and in a lab test. Slow, jumpy pages lose visitors before they read anything, especially on mobile data.
PageSpeed Insights
Google's page speed report, with real-user field data and Lighthouse lab data for mobile and desktop.
- Core Web Vitals assessment from real Chrome users: LCP, INP and CLS
- Lighthouse lab scores for performance, accessibility, best practices and SEO
- Separate mobile and desktop results
Free plan: not stated on the vendor's site. Vendor site
Landing page builders: can marketers build and test pages without a developer?
Landing page builders let marketers create campaign pages and test variants without a developer. They suit paid traffic, where each campaign needs its own page and a single goal.
Unbounce
A no-code landing page builder with A/B testing and AI traffic routing.
- Drag-and-drop landing page builder
- A/B tests across page variants
- Smart Traffic, which sends each visitor to the variant most likely to convert for them
Free plan: Free trial stated, no free plan. Vendor site
Instapage
A landing page builder with A/B testing, personalization and heatmaps.
- Drag-and-drop builder with templates, forms and popups
- A/B testing and AI-generated page variations
- Personalization and heatmaps
Free plan: Free trial stated, no free plan. Vendor site
Free CRO calculators
CRO calculators answer the arithmetic questions every test raises: what is my conversion rate, how many visitors does a test need, and is the result real? Convertica's three calculators are free, need no sign-up, and show their formulas and a worked example.
Plan a test
A/B test sample size calculator
How many visitors each variant needs before a test starts.
Check a result
Statistical significance calculator
Whether a finished A/B test result is statistically significant.
CRO tools for AI agents: the new gap
Most CRO tools measure people. Some visitors are now AI assistants browsing and acting for a person, and a page that works for a human can fail for an agent: prices loaded by a script, policies only in a footer link, forms that need a mouse. Few tools check this yet.
A few vendors have started. Zuko describes an Agent Score for how AI agents fail on forms, and Microsoft Clarity lists AI visibility tracking. You can also check by hand: view a page's source and see whether your prices, product details and policies are in the HTML itself. Agent readiness is one of the eight checks in Convertica's free CRO audit.
How to build a CRO tool stack
Build a CRO tool stack in stages: start with analytics you trust, a heatmap and recording tool and a speed test; add surveys and form analytics when you need to know why; add an A/B testing tool when you have evidence worth testing and enough traffic. Buying a testing tool first is the most common mistake.
| Stage | Add | Why |
|---|---|---|
| 1. Measure | Analytics (such as Google Analytics 4), page speed checks, a conversion rate calculator | You cannot improve what you do not measure correctly |
| 2. Observe | A heatmap and session recording tool (such as Microsoft Clarity) | Turns a leaking page into a specific problem |
| 3. Ask | On-page polls, post-purchase surveys, form analytics, user testing | Explains why people hesitate or leave |
| 4. Test | An A/B testing tool, plus sample size and significance calculators | Proves which changes work before you roll them out |
| 5. Scale | Product experimentation, feature flags, warehouse-native analysis | Runs many tests across the site, app and back end |
Each stage only pays off if the one before it works. A testing tool on top of broken analytics produces confident wrong answers.
What happened to Google Optimize?
Google Optimize was Google's free A/B testing and personalization tool, connected to Google Analytics. Google has shut it down: its support page says Optimize and Optimize 360 are no longer available as of September 30, 2023, and that Google is investing in Google Analytics integrations with third-party A/B testing tools instead.
If an older guide tells you to set up an experiment in Google Optimize, that advice no longer works. Use one of the A/B testing tools that connect to Google Analytics 4 instead. Source: Google Analytics Help.
How to choose CRO tools
Choose CRO tools by the question you need answered next, then check privacy, page speed, integrations and who on your team will use them. One tool used every week beats five installed and ignored.
- It answers a question you have now, not one you might have later
- Someone on your team will use it every week
- It masks personal data and works with your consent setup
- It loads without slowing your pages, checked before and after
- It connects to your analytics and, where relevant, your testing tool
- You own the data and can export it if you switch
- A free plan or trial lets you prove its value first
Which CRO tools does Convertica use?
Convertica's published case studies name two tools: VWO, now part of Wingify, which the dScryb case study calls "our preferred testing software", and Formisimo, now Zuko, whose form analytics split by device pointed to the mobile fix in the Empire Flippers case study.
The tools found the evidence; the gains came from what was changed. If you are not sure what to change, start there. Convertica's free CRO audit checks your page for people and for AI agents and gives you three fixes you can make now, and CRO advisory, led by founder Kurt Philip, helps your team work through it.
Questions about CRO tools
What are conversion rate optimization tools?
Conversion rate optimization tools are software that helps you find why website visitors do not convert and test changes that fix it. The main types are analytics, heatmaps and session recordings, A/B testing, surveys and feedback, user testing, form analytics, page speed tools and landing page builders.
What are the best CRO tools?
The best CRO tools are the ones that answer your next question. Most sites start with Google Analytics 4, a heatmap and recording tool such as Microsoft Clarity, and PageSpeed Insights. Add an A/B testing tool such as Wingify (VWO), Optimizely, Convert or GrowthBook once you have evidence worth testing and enough traffic.
What are some free CRO tools?
Google says Google Analytics 4 is free of charge, and Microsoft says Clarity is free forever. PageSpeed Insights runs in the browser. GrowthBook and PostHog are open source with free tiers, and Lyssna, Qualaroo, Mixpanel and Crazy Egg state free plans. Convertica's A/B test sample size, significance and conversion rate calculators are free.
What happened to Google Optimize?
Google Optimize, Google's free A/B testing tool, has been shut down. Google says Optimize and Optimize 360 are no longer available as of September 30, 2023, and that it is investing in Google Analytics integrations with third-party testing tools instead.
Do I need CRO tools to do conversion rate optimization?
You need at least analytics you can trust. Beyond that, tools make research and testing faster, but they do not decide what to change. The research, the hypotheses and reading results correctly are the work; the tools only collect the evidence and run the tests.
What is the difference between SEO and CRO tools?
SEO tools help people find your site in search: keyword research, rankings, backlinks and technical audits. CRO tools help the people who arrive take action: analytics, heatmaps, A/B testing and surveys. Some, such as page speed tools, help both.
Which CRO tools has Convertica used?
Convertica's published case studies name VWO for A/B testing and Formisimo, now called Zuko, for form analytics. VWO is now part of Wingify. This page has no affiliate links, and the tools are described from their vendors' own sites.
Can CRO tools check whether AI agents can use my site?
A few are starting to. Zuko describes an Agent Score for how AI agents fail on forms, and Microsoft Clarity lists AI visibility tracking. Agent readiness, whether AI agents can read your prices, products and policies, is also one of the eight checks in Convertica's free CRO audit.