whats-best.ai

Conversion Optimization

Statsig

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Panel rating · 6 judges · How to read the stars

Category median

Sovereignty: 3 of 4 dimensions proven

0–5 in half steps. 5 means the rubric's top anchor is met on the evidence.

by Statsig, Inc. · www.statsig.com

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Read this page as one judge. Each weighs the same scores by what they care about.

The Skeptic

Weighted verdict

A statistician who has watched too many "winners" regress to zero. Reads for the method by name, what stops a team from peeking, sample ratio mismatch checks and multiple-comparison corrections — and treats a "probability to beat" without documented assumptions as marketing.

Same scores as the panel view — this lens weights them the way this judge cares.

Scored by The Skeptic

Experiment types & delivery

How this is scored

What can be tested and where: client-side changes through an editor, server-side and feature experiments through SDKs, multivariate and multi-page tests, and personalisation — judged on what the documentation shows rather than on the feature grid.

0 — Simple A/B split of one page element through a visual editor; no server-side option, no targeting beyond URL.

3 — Client-side A/B and split-URL tests with basic audience targeting, and no SDK or server-side delivery.

5 — Client-side and server-side experiments through documented SDKs for common languages, multivariate and multi-page tests, audience targeting on behaviour and attributes, and rule-based personalisation.

8 — Feature-flag-based experiments sharing one audience and metric model with web tests, mutually exclusive experiment groups, holdouts, edge or CDN delivery, and personalisation that can itself be tested against a control.

10 — One experimentation programme across every surface: web, app, server and edge from the same platform, experiment interactions managed, a documented experiment lifecycle from hypothesis to archived result, and a library of past results a team can search.

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The Skeptic

The capability list names server-side delivery through 30+ open-source SDKs, feature flags tied directly to product data, layers and holdouts, switchback and non-inferiority tests, a no-code editor and marketing experiments — broad by any standard. But what the captures show is a feature grid: we found no public information on edge or CDN delivery, on personalisation that can itself be tested against a control, or on a documented experiment lifecycle, so I hold it in the middle of the range. 1 2

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Statistical method & guardrails

How this is scored

Which statistics decide the winner and what protects the customer from misreading them. Scored on what the vendor documents: the method by name, how peeking and multiple comparisons are handled, and whether sample ratio mismatch is detected.

0 — A "winner" or "probability to beat" figure with no documented method, no stated sample-size guidance and no warning against stopping early.

3 — The method is named (frequentist or Bayesian) but its assumptions are not documented, and nothing prevents a test from being called while it is still underpowered.

5 — Documented method with confidence or credible intervals, a sample-size or test-duration calculator, and stated guidance on when a result may be read.

8 — Sequential testing or an equivalent documented protection against peeking, correction for multiple metrics or variants, sample ratio mismatch detection, variance reduction such as CUPED, and guardrail metrics that can stop a harmful test.

10 — The statistics are auditable: methodology published in enough detail to reproduce a result, the choice of method explained per use case, raw per-visitor data available for independent re-analysis, and the interface refuses to present an underpowered result as a conclusion.

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The Skeptic

The pricing page names the techniques I read for first: CUPED for variance reduction, Bonferroni and Benjamini-Hochberg for multiple comparisons, winsorization, sequential testing against peeking, plus a power analysis tool for sizing. That is more than one method by name — peeking protection and multiple-comparison correction are both called out. But we found no public information on sample ratio mismatch detection or guardrail metrics that stop a harmful test, and the assumptions behind the named procedures are not documented, so it stays short of the top of the range. 2 1

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Snippet performance & flicker

How this is scored

The cost the client-side snippet imposes on the page it tests: blocking load, flicker of original content, script weight and the effect on Core Web Vitals — scored on what the vendor measures and publishes, not on "lightning fast".

0 — A synchronous snippet with no stated size, no flicker handling and no mention of performance.

3 — An anti-flicker snippet that hides the page until the test loads, with a timeout, and no published figures for script size or load cost.

5 — Script size and loading behaviour documented, asynchronous loading option, flicker handling explained with its trade-off, and CDN delivery of the snippet.

8 — Published performance figures including impact on Core Web Vitals, a self-hosting or first-party-domain option for the script, per-project bundles containing only active experiments, and a server-side or edge alternative for flicker-sensitive tests.

10 — Performance is a stated commitment: measured overhead published and maintained, flicker eliminated by edge or server-side rendering as a documented path, and tooling that shows the customer what their own configuration costs the page.

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The Skeptic

The one published figure is post-init evaluation latency under 1ms, which measures SDK evaluation speed, not what a snippet costs the page it tests. We found no public information on script size, anti-flicker handling and its trade-off, impact on Core Web Vitals, or a self-hosting option for the script. 1

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Analytics, data export & integrations

How this is scored

Getting results and raw data out: integration with analytics and tag management, export of visitor-level results, warehouse-native analysis, and an API — because an experiment result that cannot be checked in the customer's own data is a claim, not a finding.

0 — Results visible in the vendor's dashboard only; no export, no analytics integration, no API.

3 — CSV export of aggregated results and one analytics integration, with no visitor-level data and no documented API.

5 — Integrations with common analytics and tag managers, export of results, and a documented API for managing experiments and reading results.

8 — Visitor-level raw data export or streaming to a data warehouse, warehouse-native analysis on the customer's own metrics, CDP integration for audiences, and an API with stated limits.

10 — The platform treats the customer's warehouse as the source of truth: metrics defined once and computed there, full historical experiment data exportable in open formats, and a versioned API a team can build its own programme tooling on.

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The Skeptic

Warehouse native deployment — running the platform in the customer's own warehouse — is described on the pricing page alongside incoming data integrations, warehouse ingestion and a data export API, and that is the claim that makes an experiment result checkable in the customer's own data. But outgoing integrations and warehouse imports sit in the enterprise tier, and we found no public information on visitor-level export detail or documented API limits. 2

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European sovereignty

How this is scored

Where visitor data is processed and stored and who the contracting entity is. Independently sourced by the sovereignty pipeline; weighted higher here than in categories that hold only the customer's own data, because the script runs on every visitor to the customer's site and their behaviour is what the platform records.

0 — Non-EU vendor and contracting entity, hosting unstated, subprocessors unnamed, and visitor data leaving the EU without a stated safeguard.

3 — EU data residency offered as an option or an enterprise add-on while the contracting entity is non-EU, or the subprocessor list is absent.

5 — EU processing of visitor data as standard and an EU contracting entity, but parts of the chain — CDN, support access, analytics — are non-EU without an explained safeguard.

8 — EU hosting on named infrastructure including the delivery of the snippet, EU contracting entity, subprocessor list published, and a DPA covering the visitor data the script collects.

10 — Sovereign end to end and evidenced: vendor, entity, hosting, snippet delivery and every subprocessor European, certification published, and no visitor data reaching a non-EU party at any point.

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The Skeptic

The contracting and processing chain is American: the terms are governed by Washington law, and the privacy notice names Amplitude, Inc. of San Francisco as controller of visitor personal data, with transfers to the United States covered by standard contractual clauses and the Data Privacy Framework. 'EU hosting' appears on the pricing page only inside the enterprise warehouse-native deployment, and the captured pages name just Google and Stripe as subprocessors in passing — we found no published subprocessor list or a Statsig-specific residency statement, so this sits at the level of an EU option on a non-EU contract. 3 4 2 1

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Pricing transparency

How this is scored

A category priced by traffic — monthly tracked users, visitors or impressions — where the tier a site lands in depends on numbers the buyer has to estimate. Whether a buyer can compute the real annual cost including traffic limits, overage, server-side or personalisation modules and seats — from public pages alone.

0 — No public prices at all; every tier is a sales conversation.

3 — A starting price or a free tier exists, but the traffic metric, the limits and what happens above them are unstated — the invoice is unknowable.

5 — Tier prices public with the traffic metric and its limits defined, but at least one commonly needed piece (server-side SDKs, personalisation, overage) is unpriced or "contact sales".

8 — Every tier priced publicly with the traffic metric defined, limits, overage rates, module prices, minimum term and VAT treatment stated.

10 — Complete price computability: annual invoice derivable for a given traffic volume, set of modules and team size, with overage and every add-on published.

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The Skeptic

For the self-serve tiers a buyer can compute: Pro is $150 /mo with 5M events included and then $0.05 per 1K events, the free tier's 2M events per month and its downgrade behaviour are stated, exposure deduplication windows and the no-charge rule for 0% and 100% rollouts are documented, and the terms state taxes are the customer's with one-month auto-renewal and 30 days' notice on renewal price increases. The enterprise tier is Custom, with event- or experiment-based contracts, and warehouse native plus standalone analytics sit there — so a large deployment's annual invoice is a sales conversation, one step below full computability. 2 4

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European sovereignty — proven facts

3 of 4 dimensions proven

Built only from facts shown on the vendor's own pages. A dimension we could not prove is left open, not scored as zero.

Ownership Foreign-controlled ⚠ unverified 0/2 pts 1 Report an error
Data residency EU optional ⚠ unverified 1/3 pts 2 Report an error
Subprocessors Not determined ⚠ unverified — uncited Report an error

Where this could be wrong

What we left out

A claim that does not survive our checks costs us the claim, not the page. This is what was taken off this one.

Sources (13)

The pages every claim on this page was read from — each one checked, dated, and kept verifiable.

  1. 1 Vendor homepage www.statsig.com Checked 22 Sep 2026 Details →
  2. 2 Pricing page www.statsig.com Checked 22 Sep 2026 Details →
  3. 3 Privacy policy amplitude.com Checked 22 Sep 2026 Details →
  4. 4 Terms of service www.statsig.com Checked 22 Sep 2026 Details →
  5. 5 Experiment types & delivery — found from sitemap docs.statsig.com Checked 1 Oct 2026 Details →
  6. 6 Experiment types & delivery — found from sitemap docs.statsig.com Checked 1 Oct 2026 Details →
  7. 7 Statistical method & guardrails — found from sitemap docs.statsig.com Checked 1 Oct 2026 Details →
  8. 8 Statistical method & guardrails — found from sitemap docs.statsig.com Checked 1 Oct 2026 Details →
  9. 9 Consent & visitor tracking — found from sitemap www.statsig.com Checked 1 Oct 2026 Details →
  10. 10 Consent & visitor tracking — found from sitemap docs.statsig.com Checked 1 Oct 2026 Details →
  11. 11 Snippet performance & flicker — found from sitemap docs.statsig.com Checked 1 Oct 2026 Details →
  12. 12 Analytics, data export & integrations — found from sitemap docs.statsig.com Checked 1 Oct 2026 Details →
  13. 13 Analytics, data export & integrations — found from sitemap docs.statsig.com Checked 1 Oct 2026 Details →