Webflow's own testing add-on, Optimize, starts at $299 a month billed yearly for 25,000 page views, and Webflow's pricing page says those page views are counted across the whole site, not just the page under test. That one line decides more tool choices than any feature list: a B2B site with a busy blog pays for blog traffic it will never test.
This guide checks nine landing page testing tools against a Webflow site: how each one gets onto the page, who has to touch code, what the price meter counts and how much traffic a test needs before the tool matters. Prices come from each vendor's own pricing page, read on 21 October 2026, and adoption figures from the Webflow Apps marketplace data we pulled the same day.
Three ways a test gets onto a Webflow page
Every tool on this list does the same job, splitting visitors between versions and counting conversions, but they reach the page in three different ways. The way in decides who on your team can run a test.
Native add-on. Webflow Optimize lives inside Webflow. Webflow announced it as an add-on for Basic, CMS, Business and Enterprise Site plans on 15 October 2024. Variants and audiences are set up inside Webflow, and the same add-on handles personalisation and an AI mode that shifts traffic towards the best-performing variant.
Designer Extension apps. Optibase, Split and Humblytics install from the Webflow Apps marketplace. The app writes its own script into the site's custom code, and variants are assigned by selecting elements on the canvas. Nobody pastes anything.
Script platforms. Convert, VWO, Optimizely, PostHog and GrowthBook run on any site. Someone with access to Site settings pastes a snippet into the head once, and from then on tests are built in the vendor's own visual editor or in code. That first paste is the only developer step for most of them, though Optimizely's documentation adds conditions covered below.
| Tool | Route onto the page | Variants built in | Developer needed |
|---|---|---|---|
| Webflow Optimize | Native add-on | Webflow Designer | No |
| Optibase | Marketplace app | Webflow Designer | No |
| Split | Marketplace app | Webflow Designer | No |
| Convert | Snippet in site head | Convert visual editor | Once, for the snippet |
| VWO (Wingify) | Snippet in site head | VWO visual editor | Once, for the snippet |
| Optimizely Web Experimentation | Snippet high in site head | Optimizely visual editor | Once, and for anything beyond the editor |
| PostHog | Snippet plus per-test code; no-code editor in beta | Code, or beta editor | Yes, for each test today |
| GrowthBook | Snippet; visual editor on Pro only | Code on the free plan | Yes, unless on Pro |
Sources: Webflow pricing and updates pages; Webflow Apps listings and marketplace data; vendor pricing, documentation and tutorial pages, read 2026-10-21
What each tool costs, and what the meter counts
List price is the easy part. The meter is where tools differ, and it changes which one is cheaper for your traffic.
| Tool | Free option | Entry paid price | What is metered |
|---|---|---|---|
| Webflow Optimize | None listed | $299 a month billed yearly, $379 monthly | Site-wide page views, 25,000 a month; up to 5 concurrent tests |
| Optibase | 10,000 tested users, 1 active test | $79 a month, or $790 a year | Tested users, 20,000 a month |
| Split | Trial | $49 a month per site | Unlimited tests and visitors |
| Convert | 15-day trial | $299 a month billed yearly, $399 monthly | Tested users, 100,000 a month; 5 active experiences per project |
| VWO (Wingify) | Free trial | Quote | Monthly active users |
| Optimizely | None | Individually packaged | Not published |
| PostHog | 1M feature flag requests a month | From $0.0001 per request above that | Feature flag requests |
| GrowthBook | Starter, up to 3 users, no visual editor | $40 per seat a month for Pro | Seats |
Sources: Webflow, Optibase, Convert, Wingify, Optimizely, PostHog and GrowthBook pricing and product pages; Split's Webflow Apps listing; all vendor-sourced, read 2026-10-21
Webflow Optimize scales by site page views: $399 a month for 50,000, $549 for 100,000, $799 for 250,000 and $1,199 for 500,000, all billed yearly. The CRM and account-based integrations Webflow advertises, Salesforce, HubSpot, Marketo, 6sense and Demandbase, appear on the Enterprise card, which is sold by quote from one million page views a year.
Optibase counts tested users, meaning visitors who actually enter a test. That suits a site where the landing page is a small share of traffic. The yearly tiers are $790, $1,590 and $3,190 for 20,000, 50,000 and 120,000 tested users.
Split is the flat-rate option: one price per site, with a free month of Pro to start, according to its marketplace listing. For an agency running tests on several client sites, the per-site price is the number to multiply.
Convert is the cheapest of the established script platforms that publishes a price. Its Growth plan bundles A/B, split URL and multivariate testing and now advertises free migration from VWO.
Traffic decides whether testing is worth paying for
A testing tool cannot shorten the arithmetic. We calculated the visitors each variant needs for a standard A/B test at 95% confidence and 80% power, using the two-proportion formula most calculators use. The raw file is in our research folder.
| Baseline conversion rate | Detect a 10% lift | Detect a 20% lift | Detect a 30% lift |
|---|---|---|---|
| 2% | 80,682 | 21,109 | 9,798 |
| 3% | 53,211 | 13,914 | 6,455 |
| 5% | 31,234 | 8,158 | 3,780 |
Source: Octo calculation, two-sided test, 50/50 split, relative lifts, computed 2026-10-21
Read across the 3% row. A landing page with 10,000 visitors a month needs about 12 weeks to detect a 20% lift and about 46 weeks to detect a 10% lift. A page with 2,000 visitors a month needs more than a year for the 20% case. Our A/B testing statistics post shows that most real wins are smaller than 20%, so low-traffic pages need bigger changes, not more tests.
Two vendors suggest less traffic will do. Split's listing says its starting defaults help reach a clear answer "even on sites with only a few thousand visitors a month", and that results stay valid however often you check them. Optibase's FAQ recommends at least two weeks per test. Both are vendor claims. Bayesian and sequential methods can decide sooner and let you check results safely, but they cannot find a small lift in a few hundred conversions. On a low-traffic page, test a whole new page against the old one.
Flicker, components and the Webflow-specific checks
Three checks separate a tool that works on Webflow from one that merely installs.
Flicker. Client-side tools change the page as it loads, so visitors can glimpse the original first. Optimizely's documentation is blunt: place the snippet as high in the head as possible, load it synchronously, and do not load it through a tag manager, because asynchronous loading increases the risk of flashing. On Webflow that means pasting into Site settings, not adding it as a Google Tag Manager tag. Split says its script is about 8KB and that returning visitors get their variant before the page paints, while first-time visitors see the original content first and the variant a moment later. Optibase says it has no effect on load speed. Verify all three on your own page with a throttled connection.
Components. Split says it can assign a variant to a component instance without wrapping or detaching it, calls itself the only Webflow testing tool that can, and says it removes the losing version from the page rather than hiding it. We have not tested those claims across tools. On a component-heavy build, ask each vendor how a test behaves when the component is later edited.
Consent. Visitors in the EEA and UK need a consent signal before most tools can record them. Split lists support for five consent platforms, including Finsweet, Cookiebot and OneTrust, and says unconsented visitors see the control.
What the Webflow marketplace numbers show
Install counts are a rough guide to what other Webflow teams actually use. Webflow does not document what an install counts, so treat these as a proxy, not market share.
| App | Installs, total | Installs, last 30 days | Listed |
|---|---|---|---|
| Microsoft Clarity, behaviour only | 24,617 | 437 | January 2024 |
| Optibase | 4,993 | 35 | January 2024 |
| Humblytics | 1,490 | 0 | Not shown |
| Google Analytics 4 for Webflow Optimize | 501 | 209 | July 2026 |
| Personizely | 115 | 1 | June 2025 |
| Split | 68 | 10 | April 2026 |
| HubSpot for Webflow Optimize | 60 | 16 | July 2026 |
| Salesforce for Webflow Optimize | 50 | 21 | July 2026 |
Source: Webflow Apps marketplace page data, read 2026-10-21; Octo extraction
Optibase leads the testing apps by a wide margin. The GA4 connector for Optimize is the nearest public signal of Optimize adoption: 501 installs since July suggests hundreds of sites, not thousands, send Optimize results to GA4, though Optimize runs without it. Clarity is not a testing tool, but its count shows where most Webflow teams start: watching recordings. Microsoft's Clarity FAQ, updated October 2026, says it is free with no traffic limits. Our Webflow apps post covers it in more depth.
What changed in the testing market since Google Optimize
Google Optimize and Optimize 360 stopped working on 30 September 2023. Google's help page names three providers it built Analytics integrations with: AB Tasty, Optimizely and VWO. Two of those are now one company. In January 2026 VWO's chief executive announced a merger with AB Tasty, subject to closing conditions, creating a business with more than $100M in revenue and over 4,000 customers. VWO's pricing page now carries the Wingify name and prices on request.
For a small team, the effect is that the established script platforms sell through quotes, while Webflow's add-on and the marketplace apps publish prices.
How we would set up testing on a Webflow landing page
We build marketing sites in Webflow, so read this with that bias: a native add-on keeps everything in one tool, which is not the same as best value for your traffic.
Start with recordings, not tests. For the first month after launch we would run Microsoft Clarity and read recordings of the landing page weekly. Most early fixes, a broken form on mobile or a CTA below the fold, need no test at all.
Low traffic, under about 10,000 monthly visitors to the page. We would use Optibase's free plan or a Split trial for one large test: the current page against a rewritten one. Expect a decision in months, not weeks.
Steady traffic and a team that edits in Webflow. We would compare Webflow Optimize against Optibase on the meter that applies: site page views against tested users. A content-heavy site usually favours a tested-user meter.
Several sites, or a stack that goes beyond Webflow. Convert, VWO or Optimizely earn their cost when tests span a Webflow marketing site and a separate app. Our four-week marketing-site process leaves space in the build for the snippet, the consent setup and one QA pass, so the first test can start the week after launch.
What this means for choosing a landing page testing tool
Pick the tool after you know your traffic. If the landing page converts at 3% and gets fewer than 10,000 visits a month, any tool will do, because you can run only a handful of tests a year, and each should test a big change. If you have the traffic, choose by meter and by who edits the site: Webflow Optimize or a Designer app when marketers build in Webflow, a script platform when tests cross into other systems. Our marketing websites service page explains how we plan testing into a Webflow build.
