In-depth: PostHog vs Statsig

In-depth: PostHog vs Statsig

PostHog and Statsig both offer A/B testing and feature flags, but they're different in two important ways:

  • Statsig is a dedicated testing platform that offers advanced statistical methods for running tests. It's ideal for data scientists and growth teams in large enterprises who need to conduct complex A/B testing.

  • PostHog is an all-in-one platform for engineers and product teams who want a more straightforward approach to experimentation. In addition to A/B testing, it offers feature flags, advanced product analytics, session replays, surveys, and more.

This post compares their platforms, experimentation features, pricing, and more.

How is PostHog different?

1. We're an all-in-one platform

PostHog brings together all the tools engineers need for testing, releasing, and measuring the success of new features. Feature flags and A/B testing are only part of a suite of tools PostHog offers.

PostHog homepage features

PostHog combines usage, performance, and behavioral data with flags and experiments. Having all these dev tools together enables you to do better analysis of shipped features and make better decisions about what you are building next.

2. We're open source and transparent

PostHog is built with transparency at its core. Not only do we work in the open and give full access to our source code, we also enable others to build integrations or other services on top of PostHog, open their own PRs, or give feedback on our roadmap. PostHog's open app framework makes it easy to integrate internal tools, an advantage closed-source products like Statsig can't offer.

3. We ship weirdly fast

We update our changelog with a recap of new features every week, and often there’s even more in beta testing. We work hard to keep PostHog on the cutting edge and respond quickly to feedback from our users.

Comparing PostHog and Statsig

Platform

Statsig
compare
Experiments
Run statistically rigorous A/B/n tests and validate ideas with confidence
Feature Flags
Control feature access with precision and safely roll out changes
Product Analytics
Track usage, retention, and feature adoption with comprehensive analytics
Web Analytics
Privacy-focused web analytics with real-time data and no sampling
Remote config
Replace hard-coded values in your app with remotely configurable parameters
Web app recordings
Capture recordings from single-page apps and websites
Mobile app recordings
Capture recordings in iOS and Android apps
Surveys
Collect product feedback with no-code surveys and customizable targeting
Notebooks
Collaborate on analysis in shareable notebooks
Open source
Audit code, contribute to roadmap, and build integrations
Data warehouse experiments
Run A/B tests natively on data in your existing warehouse
Beta

Experimentation

Both tools enable you to run A/B/n and multivariate tests, set custom goals, and calculate statistical significance, but:

  • Statsig offers some more advanced testing techniques, such as multi-armed bandit, mutually exclusive, and holdout tests. It also lets you choose between Bayesian and Frequentist engines, and supports Bonferroni correction.

  • PostHog provides a more intuitive user interface and simpler setup process, making it ideal for teams who prefer a more straightforward approach to experimentation, and tight integration with its other powerful tools.

Statsig
compare
Custom goals
Define your own goals and metrics to track
Secondary metrics
Monitor impact on unrelated metrics
Statistical significance
Automatic calculation of statistical significance with configurable confidence levels
Split testing
Split participants into groups
Multivariate (A/B/n) testing
Test multiple variables simultaneously to find optimal combinations
Recommended run time
Automatically calculate the recommended run time and sample size
Statistics engine
How the results of an experiment are calculated
Bayesian or Sequential
Bayesian, Frequentist, or Sequential with Bonferroni correction
Holdout testing
Reserve a group of users who do not see any changes, so you can measure long-term impact against a true baseline
Partial
Multi-armed bandit
Optimize tests automatically by allocating traffic to the best performing variant
Pro
Mutually exclusive experiments
Isolate user groups for simultaneous, independent experiments
  • Holdout testing: It's possible to run a holdout test across multiple A/B tests in PostHog. However, the process is more manual than Statsig's, which has built-in functionality to do this.

Feature management

While both offer the core features you need, Statsig's feature flags are boolean-based, while PostHog supports multivariate flags with JSON payloads and boolean flags. This provides greater flexibility in testing and deploying different variations of a feature, making them more suitable for complex rollouts.

Statsig
compare
Boolean flags
Simple on/off flags to enable or disable features
Multivariate flags
Test multiple variants of a feature in a single flag
Payloads
Pass structured data (strings, numbers, or JSON objects) to variants for dynamic configuration without code changes
Percentage-based rollouts
Roll out features gradually to a percentage of users
Custom targeting
Target features based on user properties and attributes
Flag scheduling
Schedule flags to turn on or off automatically at specified times
Multi-environment support
Use the same flag key across PostHog projects for local development or staging
Partial
Bootstrapping
Make flags available immediately on page load without waiting for API response
Early access feature opt-in widget
Allow users to opt in or out of specified features with a built-in widget or custom UI
Remote config
Replace hard-coded values in your app with remotely configurable parameters

Product analytics

Both PostHog and Statsig offer the functionality you expect from product analytics tools, such as dashboards, graphs, and funnels. However:

  • PostHog provides deep insights into how users are interacting with your product. It includes features such as lifecycle, stickiness, correlation, and retention analysis.

  • Statsig does provide some additional insights, such as retention analysis, but its main focus is to use product analytics to set up metrics to run A/B tests on.

Statsig
compare
Autocapture
Capture events without manual tracking
Dashboards
Combine insights into shareable dashboards
Graphs & trends
Build custom insights and visualizations
Cohorts
Combine users based on properties and events for group analysis
Group analytics
Track metrics at a company and account level
Funnels
Track users through a sequence of events to find drop-off and improve conversion
Retention
Track user retention over time to understand how long users stay with your product
User paths
Understand how users navigate through your product and where they get stuck
Beta
Correlation analysis
Automatically identify significant factors that impact conversion
Lifecycle
Track user lifecycle to understand how users interact with your product
Stickiness
Track user stickiness over time to understand how long users stay with your product
Custom formulas
Perform calculations and math operations on multiple event series
SQL query editor
Write SQL queries directly against your data without a separate data warehouse

Integrations

Both PostHog and Statsig have a range of integrations that enable them to import, export, enhance, and make use of data, but PostHog being open source means you can create your own integration.

Below is a sample comparison of PostHog and Statsig's integrations. Be sure to checkout PostHog's full list of integrations.

Statsig
compare
Import from data warehouses
Import data from third-party sources like Postgres, S3, GCS, Stripe, HubSpot, and more
Batch exports
Schedule data exports to S3, Snowflake, BigQuery, and more
Realtime event streaming
Send events to Slack, webhooks, and 40+ tools as they happen
Zapier
Trigger Zapier automations
Sentry
Send and receive data from Sentry
Datadog
Send feature flag and event data to Datadog
Slack
Alerts and notifications for Slack
Microsoft Teams
Alerts and notifications for Microsoft Teams

Security and compliance

Both PostHog and Statsig enable companies to remain secure and compliant with privacy regulations. Companies can customize the levels of user privacy related to these platforms to their needs.

Statsig
compare
User privacy options
Anonymize users, drop personal data
History and audit logs
Manage and view edits and related users
Enterprise
GDPR-ready
Can be compliant with GDPR
HIPAA-ready
Can be compliant with HIPAA
Enterprise
SOC 2 Type II
SOC 2 security certification
2FA
Enforce login with two-factor authentication
SAML/SSO
Use SAML or single sign-on authentication
Enterprise
Enterprise
Flag approvals
Require approvals to change flags
Flag permissioning
Control who can edit and modify flags

Frequently asked questions

Who is PostHog useful for?

PostHog is built for startups and their engineers. It provides all the tools startups need to build successful products. The people who find PostHog most useful are founders, product engineers, and growth engineers.

Companies that use PostHog feature flags and experiments include Y Combinator, Vendasta, and AssemblyAI.

Who is Statsig useful for?

Statsig is for teams that require advanced experimentation capabilities and more sophisticated statistical methods. It's ideal for data scientists and growth teams who need to conduct complex A/B testing.

Teams that frequently run multiple experiments on the same surface concurrently will appreciate Statsig's ability to handle mutually exclusive experiments and implement Bonferroni correction.

Can I migrate from Statsig to PostHog?

Yes. See our Statsig to PostHog migration guide for more.

How much does PostHog cost?

Feature flags and experiments are free for up to 1M requests per month. Beyond that, it costs $0.0001/request (or $1 per 10,000 requests). There are discounts for high-volume users, non-profits, and startups.

Other products, like product analytics and session replay, have separate but similarly structured pricing.

How much does Statsig cost?

Statsig is free up to 1M requests per month. Thereafter, it's $150 per month for up to 5 million metered events, and then $50 per every 1 million events thereafter.

Does PostHog offer discounts for nonprofits and startups?

Yes, PostHog offers both. Nonprofit organizations can contact our team and are usually eligible for a discount, while startups can sign up for $50,000 of free credit (and a host of other perks) in the PostHog for Startups program.

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