Varify.io vs VWO

Varify.io

The client side is documented in depth — a visual editor with redirect and split-URL tests, full-factorial multivariate, multi-page experiments, multiple variants, audience and page targeting, and mutual exclusion of experiments — which already exceeds a basic split-and-target product. Server-side testing appears only as a label in a feature list with no SDK documentation behind it, and we found no public information on holdouts, feature flags, edge delivery or personalisation.

VWO

The captured pricing page shows A/B/n, split and multivariate testing with a visual and code editor, multi-armed bandit campaigns, mutually exclusive groups and SPA support, plus personalisation and feature management as product suites. What decides the score against it: the evidence is a feature grid, and we found no public information on server-side SDKs, edge delivery, holdouts or personalisation tested against a control.

Varify.io

Credit where due: the machinery is named — one-sided chi-square for binomial targets, one-sided Student t-test for value metrics, an optional two-tailed setting, a Bayesian alternative with a runtime forecast — alongside an A/A test facility and concrete reading guidance (ten days minimum, 500 conversions per variant, at most three metrics, ignore interim significance). All of it is advisory: we found no public information on sequential testing against peeking, any multiple-comparison correction, sample ratio mismatch detection or variance reduction, and nothing prevents an underpowered test from being called. The Bayesian option outputs a probability that a variant is better, and we found no public information on its assumptions, the prior included — a figure I treat as marketing until the prior is on the table.

VWO

Sample ratio mismatch detection and guardrail metrics are named as Pro-tier features — the first two things I check — and that is real. But nowhere on the captured pages is the statistical method named, and we found no public information on confidence or credible intervals, sample-size guidance, any protection against peeking, or correction for multiple comparisons; a feature named on a pricing page is a promise, not a method.

Varify.io

Documented where it counts: variant play-out and tracking are separated so variants can be served while tracking waits for consent, the snippet may run consent-free, Google Tag Manager Consent Mode V1 and V2 plus consent-tool integrations are offered, and storage is localStorage rather than cookies, backed by a written ePrivacy position on why the vendor considers it consent-exempt. We found no public information on a list of storage keys with their lifetimes or on IP anonymisation, retention appears only generally (log files at most fourteen days), and the consent-free position is argued on a marketing page rather than mapped to §25 TDDDG.

VWO

The privacy policy states outright that it applies to the customer only and not to the visitors of their websites, so we found no public information on what the script stores on a visitor's device or when it runs relative to consent. A tracking opt-out for end users is mentioned and a compliance page is referenced, which is what lifts this off the floor.

Varify.io

An 11.5 KB snippet size is published, and the anti-flicker documentation is unusually honest: the script is optional, the four-second maximum hide is configurable, and the vendor states in writing that it can negatively affect Core Web Vitals and SEO. We found no public information on asynchronous loading, CDN delivery of the snippet, measured Core Web Vitals impact, self-hosting, or per-project bundles.

VWO

Self-hosting is offered at the Enterprise tier and the privacy policy describes CDN delivery from ten edge locations, so delivery is at least described. We found no public information on script size, flicker handling, asynchronous loading or any measured impact on Core Web Vitals — an anti-flicker snippet with a timeout is the minimum I would expect to see documented, and it is absent from the captured pages.

Varify.io

An experiment result you can check in your own data is a finding, not a claim — and this product gets that far: automatic GA4 evaluation, integrations for Adobe Analytics, etracker, econda, Matomo, Piwik Pro and PostHog, results export, and a BigQuery integration placing raw, line-by-line, unsampled experiment data in the customer's own project as goals and segments. The experiment API is offered as an "expert function"; we found no public information on its rate limits, versioning, or on a CDP integration for audiences.

VWO

An integrations section exists, pull-based integrations sit in the Pro tier, API access is gated to Enterprise, and Google Analytics is named as a connected tool. We found no public information on visitor-level export, warehouse or CDP integration, or documented API limits — an API a customer cannot read about is a line on a pricing page, not an audit path for a result.

Varify.io

A German contracting entity in Grünwald, a Frankfurt hosting claim, and the privacy policy explains DPF-or-SCC safeguards for the US providers used on the vendor's own website. But the Frankfurt claim lives in marketing copy: we found no public information in the privacy policy on where product data is stored, on the hosting provider of the testing product, or on subprocessors of the hosted product, and the captured pages name the contracting entity differently — Varify Software GmbH in the imprint, Varify GmbH in the privacy policy.

VWO

The contracting entities are Wingify Software Pvt. Ltd. (India) and Wingify Inc., and the privacy policy states all customer data is stored centrally in Washington DC and Dallas in the United States; the safeguards we could find are standard contractual clauses, a data processing addendum and an Article 27 EU representative. We found no public information on an EU hosting option or a published subprocessor list, so the script's data path runs to the US as standard.

Varify.io

Flat pricing with unlimited traffic removes the estimation game entirely: Growth and Pro prices are published monthly and annually, domain and active-experiment limits are stated, and a 15-day trial needs no credit card. Deductions at the edges: the captured pages give different figures for the entry price — €119 per month on the homepage, a starting price of 199 € per month on the pricing page — AI features are billed in AI credits whose package price we found no public information on, Enterprise services are quoted separately, and minimum term and VAT treatment are unstated.

VWO

The pricing page states there are no fixed plans, only a custom proposal built around the buyer's goals, and we found no public figures for any tier, module or overage; add-ons like Predictive Data and Data Studio are named but unpriced. The traffic quota appears only as an unanswered question about a shared monthly tracked users quota, and a trial is the only visible entry point — the annual invoice is not derivable from public pages.