Accelerate vs Optimizely
Optimizely Web Experimentation is an enterprise testing platform: a snippet on your pages and a visual editor in their app. Engineers get server-side SDKs and feature flags, and AI agents suggest the next test. Its WordPress plugin closed in 2020 and its prices are set per contract. Accelerate is a WordPress plugin. It tests and personalizes blocks inside the block editor and renders them server-side. It runs on first-party analytics it collects itself, free up to one million page views a month. If the job is a WordPress site, the smaller tool is the right size.
Checked 25 September 2026 against optimizely.com's product and pricing pages and the Optimizely Classic listing on wordpress.org, and published the same day. Written by Human Made, who make Accelerate (so read the Optimizely column as their claims and ours as ours).
Choose Optimizely if
- Experimentation is a programme across products, apps and back ends, not a WordPress site.
- Engineers need server-side experiments, SDKs and feature flags, and marketers need a visual editor, in one platform.
- You want an AI layer that proposes tests, writes variations and summarises results across the whole programme.
- Procurement expects an enterprise contract, and the budget is there for one.
Choose Accelerate if
- The site is WordPress, built with the block editor, and the people running tests are the people editing content.
- You want no snippet, no swap in the browser, and no third-party tracker on the page.
- You want testing, personalization and analytics reading one set of first-party data.
- You want to know the price before a sales call, and a free plan that covers a real site.
- Agents are part of how you work and you want them reading results and acting through MCP.
Feature by feature
Thirteen things a buyer asks about, answered for both. Where a claim is Optimizely's, it is their wording from their site.
| Accelerate | Optimizely | |
|---|---|---|
| What it is | A WordPress plugin. Everything runs in wp-admin and the block editor. | Web Experimentation, one product in an enterprise digital experience suite that also sells a CMS, a content marketing platform, analytics and personalization. |
| Getting it onto a site | Install the plugin, done. | A JavaScript snippet on every page. The official WordPress plugin, Optimizely Classic, was closed in March 2020 at the author’s request. |
| Where you build variants | In the block editor, as ordinary blocks. | In their visual editor for no-code web tests, or in code for server-side experiments and feature flags. |
| How variants render | Server-side, in the page. Nothing swaps in after load. | In the browser for web tests, which they describe as flicker-free, or server-side through their SDKs. |
| Full-page caching | The same cached page serves every variant, so the hit rate does not move. | Not affected for web tests, because the swap happens in the browser. |
| Accelerate | Optimizely | |
|---|---|---|
| Statistics | Bayesian. A live probability to win, no fixed sample size, traffic drifts to the leader as the evidence comes in. | Their Stats Engine, with multivariate tests, bandits and, in their words, AI that helps you reach statistical significance quickly. |
| Winner into live content | One click in the editor, or automatic once it clears the threshold you set. | The winner keeps being served by the snippet. Making it the real page is a change you make in WordPress afterwards. |
| Test types | A/B tests on any block, plus title and featured-image tests on the page. | A/B, multivariate and bandit tests, server-side experiments and feature flags across web, apps and back ends. |
| Accelerate | Optimizely | |
|---|---|---|
| Personalization | Built in. Audiences by location, device, behaviour or UTM, one variant per audience, same editor. | A separate product, Optimizely Personalization, with an AI strategist that stages campaigns for you. |
| Analytics | First-party site analytics in wp-admin. Tests and audiences read the same numbers. | Optimizely Analytics, a separate warehouse-native product. |
| Where the data lives | Collected by a script served from your site, no third-party tracker, retained 30 to 90 days by plan. | In their cloud, with the enterprise controls you would expect and negotiate. |
| 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. | Opal, a library of AI agents that recommend what to test next, write variations and summarise results. |
| WordPress-specific | The whole product. Blocks, synced patterns, wp-admin, the same first-party data. | Nothing current. The plugin closed in 2020; integration is the snippet. |
Pricing, side by side
One of these has a price list. Optimizely's pricing page says every plan is individually packaged, so the table shows the products and not the numbers.
| 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 |
|---|---|---|---|
| Web ExperimentationVisual editor, Stats Engine, Opal AI | On request | Not published | Per contract |
| Feature ExperimentationServer-side, flags, SDKs | On request | Not published | Per contract |
| PersonalizationSeparate product | On request | Not published | Per contract |
Products as listed on optimizely.com. Pricing is by conversation: their page reads, in full, that every plan is individually packaged and they will create a plan together with you.
Where Optimizely is stronger
Reach and rigour. Optimizely runs experiments anywhere code runs: web, mobile, back end, through a visual editor for marketers and SDKs for engineers, with feature flags, multivariate tests, bandits and a Stats Engine that has been argued over in public for a decade. Opal adds agents that propose tests and write variations across the whole programme. If experimentation is how your company ships software, this is the tool built for that.
What Optimizely sells around Web Experimentation, in their words
- Agentic CMS
- Content marketing platform
- Analytics
- Personalization
- Feature experimentation
- Opal AI agents
Accelerate is one plugin that does testing, personalization and analytics inside WordPress. It is not trying to be the suite.
Where Accelerate is stronger
Fit. On a WordPress site, a test or an audience variant is a block, edited by the person who edits the page, rendered by the server with the rest of it. No snippet, no swap, no second analytics tool, no plugin that was closed six years ago. When a variant wins it becomes the page with one click. The price is on the website, the free plan covers a million page views, and agents get the same access a person does, through 41 abilities over MCP.
Common questions
- Is Accelerate an Optimizely alternative for WordPress?
- For A/B testing and personalization on a WordPress site, yes. Optimizely is an enterprise experimentation platform attached to a site with a snippet, sold as one product among a CMS, analytics and personalization, with pricing set per contract. Accelerate is a plugin that does testing, personalization and analytics inside WordPress on the site’s own data, with the price on the website.
- Does Optimizely have a WordPress plugin?
- Not any more. Optimizely Classic on wordpress.org was closed in March 2020 at the author’s request, and its last update was nine years before that. Today you add the Optimizely snippet to your theme or through a tag manager and build variants in their editor.
- Which is cheaper?
- Optimizely does not publish prices. You tell them what you need and they package a plan. Accelerate is free up to one million tracked page views a month, then $150 a month up to ten million, and the numbers are on the pricing page.
- Does the snippet slow the site down?
- Optimizely describes its web delivery as fast and flicker-free. That is their claim and we have not measured it. Accelerate renders variants on the server, so there is nothing to swap in and nothing for a cache to miss.
- When is Optimizely the right answer?
- When experimentation is a programme across products, apps and back ends, with a team that lives in the tool, budget for an enterprise contract, and a need for server-side SDKs and feature flags. That is a different job from testing and personalizing a WordPress site, and Accelerate does not pretend to do it.
Also compared: Accelerate vs Nelio A/B Testing and Accelerate vs VWO, now Wingify.
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 you need the platform, Optimizely will talk to you at optimizely.com.