Accelerate vs Nelio A/B Testing
Both are WordPress plugins that run A/B tests from wp-admin and keep working with full-page caching. Both can write the winner back into the live page. Nelio tests more kinds of things, themes and menus and WooCommerce products included, and adds heatmaps. It charges by tested page view, from about $42 a month once you outgrow a 500-view free plan. Accelerate tests and personalizes blocks inside the block editor, on first-party analytics it collects itself. It is free up to one million page views a month. If your site is built with blocks, it is a closer call than the two price lists suggest.
Checked 25 September 2026 against neliosoftware.com, its pricing page and the wordpress.org listing, and published the same day. Written by Human Made, who make Accelerate (so read the Nelio column as their claims and ours as ours).
Choose Nelio if
- You want to test something that is not a block: a whole theme, a menu, a CSS change, a WooCommerce product page.
- Heatmaps and session recordings have to live in the same tool as the tests.
- You build with Elementor or another page builder rather than the block editor.
- The pages you test get a few thousand views a month, where per-view pricing stays cheap.
Choose Accelerate if
- Your site is built with the block editor and you want tests and audience variants to be ordinary blocks in it.
- You want testing, personalization and site analytics reading one set of first-party data, with no third-party tracker on the page.
- You want a probability to win you can read at any moment, with traffic moving to the leader while the test is still running.
- You run a high-traffic site, or an agency with several clients, where a million free page views a month changes the maths.
- Agents are part of how you work and you want them reading results and acting through MCP, not screenshots.
Feature by feature
Twelve things a buyer asks about, answered for both. Where a claim is Nelio's, it is their wording from their site or their listing.
| Accelerate | Nelio A/B Testing | |
|---|---|---|
| Where you work | The block editor. A test or an audience variant is just another block. | wp-admin, in its own test editor, with results in a cloud dashboard. |
| What you can test | Any block, in any post, page or synced pattern. | Pages, posts, headlines, menus, widgets, themes, CSS, JavaScript, synced patterns, WooCommerce products and popups. |
| How variants render | Server-side, in the page. Nothing swaps in after load. | By the plugin, with a JavaScript layer for some test types. |
| Full-page caching | The same cached page serves every variant, so the hit rate does not move. | Compatible with caching plugins, in their words on wordpress.org. |
| Accelerate | Nelio A/B Testing | |
|---|---|---|
| Statistics | Bayesian. A live probability to win, no fixed sample size, and traffic drifts to the leader as the evidence comes in. | Frequentist. Results show a confidence level and how many page views you need to reach 90 percent. |
| Winner into live content | One click in the editor, or automatic once it clears the threshold you set. | One click replaces the page or post with the winner. |
| Accelerate | Nelio A/B Testing | |
|---|---|---|
| Personalization | Built in. Audiences by location, device, behaviour or UTM, one variant per audience, same editor. | Tests can be segmented by device, referrer, location or behaviour. There is no personalization on its own. |
| Analytics | First-party site analytics in wp-admin. Tests and audiences read the same numbers. | Test results, conversion rates and visitor stats. Site analytics come from whatever else you run. |
| Heatmaps and recordings | None. | Heatmaps, clickmaps and scrollmaps on every plan. Session recordings on Basic and Enterprise. |
| AI | 41 abilities over MCP, so Claude Code, Cursor or any agent can read results and act on them. Block Runner turns HTML into blocks. | Nelio AI suggests tests from your content and visitor behaviour. |
| Page builders | Block editor only. | Block editor, Elementor and other major page builders. |
| WooCommerce | No product-specific tests. | Product titles, images, prices and layouts. Order value as a goal. |
Pricing, side by side
The unit is the whole story. Nelio counts views of pages that are in a test. Accelerate counts every tracked page view on the site, and gives away a million of them a month.
| Plan | Price | Included each month | Sites |
|---|---|---|---|
| Free30-day analytics retention | $0 | 1 million page views | 1 site |
| Premium90-day retention, email support | $150 / month | 10 million page views | 1 site |
| AgencyWhite-label reporting | Scoped with you | Per site | All client sites |
| EnterpriseData isolation, SLA | Custom | Unlimited | Custom |
Monthly. No overage bills: we get in touch when a site is consistently over its plan and move it up.
| Plan | Price | Included each month | Sites |
|---|---|---|---|
| FreeUnlimited tests, heatmaps | $0 | 500 tested page views | 1 site |
| BasicAdds session recordings | about $42 / month | 5,000 tested page views | 1 site |
| ProfessionalAdds scheduling, quota control | about $159 / month | 50,000 tested page views | 5 sites |
| EnterpriseEverything, priority support | about $427 / month | 200,000 to 1,000,000 | Unlimited |
Monthly billing as shown to a visitor in Europe, VAT included where applicable. Yearly billing saves 20 percent, extra capacity is sold in blocks, and paid plans carry a 30-day money-back guarantee.
Where Nelio is stronger
Breadth. Nelio has spent 13 years widening what a WordPress site can test, and heatmaps ship on the free plan, session recordings are in the product, and Elementor is supported alongside the block editor. If the question is “can I test this?”, their answer is yes more often than ours.
What Nelio can put in a test, in their words
- Pages
- Posts
- Headlines
- Menus
- Widgets
- Themes
- CSS
- JavaScript
- Synced patterns
- WooCommerce products
- Popups
- Custom post types
Accelerate tests one thing: any block, anywhere it appears. That is narrower, on purpose.
Where Accelerate is stronger
The loop. Accelerate measures a site, tests it, personalizes it and ships the result as one system, all as blocks in the editor and all on the same first-party data. Variants render server-side, so nothing swaps in after load. Results are Bayesian, so you read a probability to win at any point rather than waiting on a sample size. Personalization is a feature, not a segment filter on a test. The free plan covers a million page views a month, and agents get the same access a person does, through 41 abilities over MCP.
Common questions
- Is Accelerate a Nelio A/B Testing alternative?
- For block-level tests, yes. Both run from wp-admin, both keep full-page caching working, and both can write the winner into the live page. The difference is scope: Nelio tests more kinds of things and adds heatmaps, Accelerate adds personalization and first-party analytics on the same data and never leaves the block editor.
- Which is cheaper?
- Depends on traffic. Nelio charges by tested page views, so a page pulling 20,000 views a month while a test runs needs the Basic plan at about $42 plus extra capacity on top. Accelerate is free up to one million tracked page views a month across the whole site, then $150 a month up to ten million.
- Can I run both at once?
- You can install both. Just do not test the same block or page with both, because each will count the other’s visitors and neither result will be clean. Pick one per page.
- Which is better for an agency with many client sites?
- Nelio prices sites into its tiers: five on Professional, unlimited on Enterprise. Accelerate’s Agency plan is scoped per client and comes with white-label reporting, and the free plan is enough to prove the work on a first client site before anyone pays for anything.
- Does either one slow the site down?
- Both say they work with full-page caching and both do the heavy lifting away from the page. Accelerate renders variants server-side, so there is no swap after the page loads. Nelio uses a JavaScript layer for some test types.
Also compared: Accelerate vs VWO, now Wingify and Accelerate vs Optimizely.
Try Accelerate on a real page.
Free up to a million page views a month, no credit card, and the first test takes minutes. If Nelio is the better fit for what you need to test, no hard feelings: their free plan is at neliosoftware.com.