The best Optimizely alternatives & competitors, compared
Contents
1. PostHog
- Founded: 2020
- Similar to: VWO, LaunchDarkly
- Typical users: Engineers and product teams
- Typical customers: Mid-size B2Bs and startups

What is PostHog?
PostHog (that's us 👋) is an open-source platform that includes A/B testing, feature flags, product analytics, session replay, and user surveys. This means it's also an alternative to tools like Mixpanel (product analytics) and Hotjar (session replay and surveys).
Typical PostHog users are engineers and product managers at startups and mid-size companies. Customers include Supabase, ElevenLabs, and Airbus.
According to BuiltWith, as of April 2024, 5,610 (0.5%) of the top 1 million websites use PostHog. This is slightly more than Optimizely's 5,353.
Key features
Feature flags: Safely rollout features with local evaluation (for faster performance), JSON payloads, and instant rollbacks.
A/B tests: Up to 9 test variations, primary and secondary metrics. Automatically calculate test duration, sample size, and statistical significance.
Product analytics: Funnels, user paths, retention analysis, custom trends, and dynamic user cohorts. Also supports SQL insights for power users.
Surveys: Target surveys by event or person properties. Templates for net promoter score (NPS), product-market fit (PMF) surveys, and more.
Session replays: Including event timelines, console logs, network activity, and 90-day data retention.
How does PostHog compare to Optimizely?
The core of feature flags and experimentation are similar between the two. The big difference is that PostHog is free, open-source, and has analytics built in, while Optimizely has a range of enterprise content, commerce, and collaboration tools.
Why do companies use PostHog?
According to reviews on G2, companies use PostHog because:
It replaces multiple tools: PostHog can replace Optimizely (feature flags and A/B testing), Mixpanel (analytics), and Pendo (feedback and session replays). This simplifies workflows and ensures all your product data is in one place.
Pricing is transparent and scalable: Reviewers appreciate how PostHog's pricing scales as they grow. There's a generous free tier they can use forever. Companies eligible for PostHog for Startups also get $50k in additional free credits.
They need a complete picture of users: PostHog includes every tool necessary to understand users and improve products. This means creating funnels to track conversion, watching replays to see where users get stuck, testing solutions with A/B tests, and gathering feedback with user surveys.
Bottom line
Being free, self-serve, and sharing many of the same features, PostHog is a great alternative to Optimizely. This is especially true for startups and scale-ups looking for dev tools, though marketing teams may prefer Optimizely for experiments due to its visual editor.
2. VWO
- Founded: 2009
- Similar to: PostHog, Optimizely
- Typical users: Product managers, engineers, UX designers
- Typical customers: Enterprise B2B and B2C companies optimizing customer experiences

What is VWO?
VWO is a digital experience optimization platform that aims to maximize conversion with tools like A/B testing, personalization, funnels, heatmaps, session replay, and customer analytics.
The VWO platform is home to multiple different products including testing, insights, data, personalize, plan, and web rollouts each with its own feature sets and pricing.
According to BuiltWith, 9,183 of the top million sites use VWO as of April 2024. This is nearly double Optimizely's 5,353.
Key features
A/B testing: Improve and optimize experiences and conversions with web, mobile, and server-side A/B testing.
Data platform: Collect and analyze customer data across your stack using SDKs, third-party integrations, and direct uploads.
Insights: Understand your users with session recordings, heatmaps, analytics, and surveys.
Personalization: Create and tailor user journeys and campaigns for specific audiences, locations, and times.
Planning: Ideate, prioritize and plan optimization campaigns in one location. Connect them directly to data as well.
How does VWO compare to Optimizely?
Optimizely and VWO are both massive, multi-product platforms with many similarities. They both focus on optimizing user experience and have tools like A/B tests, visual editors, program planners, and personalization to help with this.
The difference is that Optimizely has CMS and content tools while VWO has more product tools like session replays, surveys, and behavioral analytics.
Why do companies use VWO?
Reviewers on G2 are big fans of VWO for these reasons:
Support: VWO's support staff are knowledgeable, helpful, and responsive. This helps reviewers get the most out of the platform and leaves them with a positive impression.
Multi-function: Reviewers like that they can combine A/B tests with surveys, funnels, session replays, and analysis tools to optimize the complete user experience.
Becoming data-driven: VWO enables technical and non-technical to make more and better data-driven decisions by being the complete source of experience data.
Bottom line
VWO is a solid alternative for enterprise users looking for optimization tools, provided you don't need CMS functionality as well. If you are smaller or product-focused, there are likely less complex and cheaper options.
3. LaunchDarkly
- Founded: 2014
- Similar to: PostHog, Kameleoon
- Typical users: Enterprise engineering teams
- Typical customers: Massive engineering-focused enterprises

What is LaunchDarkly?
LaunchDarkly is a feature flag and A/B testing platform helping developers de-risk releases, target experiences, and optimize their product. It provides automation and governance features to ensure enterprises are following engineering best practices.
According to BuiltWith, 1,019 of the top 1 million sites use LaunchDarkly. This is nearly 5x less than Optimizely's 5,353 but may undercount mobile and backend usage. Google Trends confirms that Optimizely is better known than LaunchDarkly, but not by a large margin.
Key features
Feature flags: Control and target the release of features using multi-variate flags with real-time updates.
Experimentations: Run A/B/n tests against metric groups and release winning variants.
Automation: Automate and schedule progressive rollouts, trigger workflows.
Governance: Audit flag changes. Get visibility into flag state across platforms.
How does LaunchDarkly compare to Optimizely?
LaunchDarkly focuses more on feature releases and development best practices, while Optimizely focuses on improving digital experiences. This means LaunchDarkly has more robust governance and automation tools but is missing ones for non-developers like a visual editor, CMS, or project management.