GrowthBook vs Statsig

GrowthBook

Flags, the visual editor and URL redirects can all run as experiments through the same feature and metric model, with namespaces for mutually exclusive tests, holdouts, bandits and a Cloudflare edge app that rewrites visual changes into the HTML before the browser sees it. We found no public information on personalisation as a named capability that can itself be tested against a control group, which is the one gap against the top of this scale.

Statsig

The published capability list gives me feature flags tied to product data, layers, holdouts, autotune, a no-code editor and 30+ SDKs — the flag-plus-metric machinery I want under one audience model. We found no public information on personalisation that can itself be tested against a control, on edge or CDN delivery, or on multivariate and multi-page tests.

GrowthBook

Both a Bayesian and a frequentist engine are documented by name with priors spelled out, plus sequential and multivariate tests, CUPED, sample ratio mismatch detection, multiple-testing corrections with the family of tests defined, guardrail metrics and a minimum-data floor so you aren't drawing conclusions too early. The implementation is open source and every query is visible SQL in my own warehouse, so I can re-run the numbers myself before shipping a price change.

Statsig

Sequential testing, CUPED, Winsorization, Bonferroni and Benjamini-Hochberg corrections, switchback and non-inferiority tests, plus power analysis, are all named publicly — real peeking and multiple-comparison protection for my conversion numbers. We found no public information on sample-ratio-mismatch detection, on guardrail metrics that halt a harmful test, or on whether the engine is frequentist or Bayesian.

GrowthBook

The consent mechanics are documented where I'd need them: persisting the gbuuid identifier cookie can be held back until the visitor consents via a setting plus a "growthbookpersist" event, assignment itself runs on stateless hashing with no cookies needed, and sticky bucketing can be enabled per user only after consent. We found no public information on consent-management-platform integrations, IP anonymisation or EU legal-basis guidance for testing, and the privacy notice states DNT signals are not honoured.

Statsig

The captured privacy pages are Amplitude's site-wide notice: cookie categories including advertising are listed, consent is named among the legal bases, and Global Privacy Control is honoured where law requires. We found no public information on what the Statsig script does before consent, on consent-platform integration, on a cookieless mode, or on anything addressing §25 TDDDG.

GrowthBook

Flicker is addressed where it counts: the edge app evaluates flags and runs visual experiments on Cloudflare Workers to cut flicker before HTML ships, URL redirects run without flicker, the SDK payload is served from a global CDN, and self-hosters can run their own proxy or CDN. The docs are honest that the default edge setup makes a blocking call on every user request unless you build the KV push model — but we found no published figures for script weight or Core Web Vitals impact, which is what I'd want before a peak-season sale.

Statsig

The only performance figures I can find are post-init evaluation latency under 1ms and 99.99% infrastructure uptime — nothing about what the snippet does to my product page. We found no public information on script weight, flicker handling, asynchronous loading or Core Web Vitals impact, and for a shop where a tenth of a second shows up in the conversion rate that is the question I most needed answered.

GrowthBook

Warehouse-native is real here: metrics are built with SQL and computed in my own Snowflake, BigQuery, Databricks or Redshift with the statement that no PII ever leaves the warehouse, and a documented REST API covers experiments, results, features and segments. Slack, Shopify, Datadog and Segment tracking are listed and results export as CSV — though we found no public information on stated API limits or full historical export in open formats.

Statsig

Warehouse-native deployment — running Statsig in my own data warehouse — plus a data export API, warehouse ingestion and incoming and outgoing integrations are all published, which is how I would verify a lift claim against my own numbers. We found no public information on visitor-level export, CDP audience integration, or API rate limits.

GrowthBook

The contracting entity is GrowthBook, Inc. of Anaheim, California, hosting is stated as GrowthBook on AWS with information processed in the United States, and the privacy notice has visitors consent to US transfer while the website terms say the site is for persons located in the United States. US AI providers are named for optional features, but we found no public information on an EU residency option, a published subprocessor list or a DPA covering the visitor data; the documented mitigations are self-hosting and warehouse-native mode, where no visitor-level data leaves my systems.

Statsig

EU hosting appears only as an enterprise, warehouse-native line item, while the contracting entity is Statsig, LLC under Washington State law and the privacy notice states personal data may be transferred to the United States with standard contractual clauses as a safeguard. The captured pages name only Google for login and Stripe for payments; we found no published subprocessor list and no EU processing commitment for the testing script itself.

GrowthBook

Starter is free and Pro is "$40 / seat / month" with published usage limits and overage rates — managed warehouse "2M events/mo (then $30/M)", CDN bandwidth "20GB/mo (then $1/GB)" and CDN requests "2M/mo (then $10/M)" — so a December traffic spike costs extra at a stated rate rather than jumping a tier. Enterprise is custom, and we found no public information on minimum term or VAT treatment, which keeps the annual invoice from being fully computable from the public pages alone.

Statsig

The paid tiers are unusually computable: Pro at $150 /mo with 5M events included and $0.05 per 1K events overage billed next period, a free Developer tier at 2M events per month, session-replay caps, dedup windows, what is not charged, monthly renewal with 30 days' notice on increases, and taxes on my side — an overage rate rather than a December tier-jump is exactly what I ask for. The Enterprise tier is Custom, analytics standalone and warehouse-native sit behind it, and we found no public information on seat pricing, so the annual invoice is computable only at the bottom end.