Test your website without a developer.
Stellar is the lightweight A/B testing tool for marketing teams on Shopify, Webflow, WordPress and any other site. Edit a page visually, launch a test in minutes and keep the version that converts more. Free to start, one 5.4KB script.
Pick a page and start a test
Every page is ranked by the visitors it gets and how many of them convert. Pick the one with lots of traffic and a weak conversion rate, then launch a test on it in the same screen.
Change your page without code
Click a headline, button or section and edit it on your live page. Nothing changes for visitors until the test starts.
See which version wins
Each test shows the winning version, how sure the result is and how much more it converted. You decide when to apply it.
Find what to fix, then test it.
Heatmaps and funnels show where visitors lose interest on your site or a client's. Test the fix on the same page, with the same tool, without opening a ticket.
Click and scroll heatmaps show which elements get attention and which get skipped. Spot the button nobody reaches before you redesign anything.
- See where visitors click
- See how far they scroll
- Compare desktop and mobile
Follow visitors from the landing page to signup or purchase. Find the step that loses the most people and start there.
- Map every step to purchase
- Spot the biggest drop-off
- Filter by source or device
Change the step that leaks, run it against the original and keep it only if it converts more. Your live page does not change until you apply the winner.
- Edit directly on your page
- Split traffic 50/50
- Bayesian confidence, no guesswork
A/B testing that never stops.
Pick the elements Stellar can change and the goal to improve. Autopilot writes a challenger, tests it against your best version, keeps the winner and starts the next test on top of it. Approve every test or let it run on its own.
See how Autopilot worksWorks with your website and tools.
Add one 5.4KB script to Shopify, Webflow, WordPress, Wix, Framer, Squarespace or a custom site, directly or through Google Tag Manager. Send experiment data to GA4, Mixpanel or Segment, or test inside React and Next.js apps with the SDK.
ShopifyWebflowWordPressWixCustom site16ms impact on LCP.
Google Analytics 4Who it is for
Test landing pages, pricing and copy without waiting on a developer or a sprint.
20k to 250k visits a month is enough traffic to get answers, and too little to justify VWO or Optimizely.
Run tests across every client site from one account and show them the results.
From signup to a live test in minutes.
The teams that get the most out of Stellar launch their first test in the first week. There is no setup call, no SDK to wire and no developer on the critical path.
Add the snippet
2 minPaste one line in your site's head or add it with Google Tag Manager. Stellar checks the install for you and tells you when it is live.
Edit your page
3 minOpen the visual editor on your live page. Change a headline, swap an image or move a button. Add custom CSS or JavaScript if you need more.
Launch and watch
Same daySet the goal, split the traffic and go live. Results update in real time with Bayesian confidence, so you know when you have a winner.
Ask your experiment data anything.
Connect Stellar to Claude, Cursor, ChatGPT or any assistant that supports MCP. Ask which tests won, where visitors drop off and what to test next, in plain English. Read-only, across every project you manage.
Set up the MCP server- 1Ask about your experiments
- 2Get the winner and the why
- 3Decide what to test next
What marketers say.
“It’s exactly what we were looking for. No fluff, easy setup, and a free way to test before committing. We’re using it across every client now. It’s affordable, intuitive, and it simply does what it says it’s going to do.”
Performance Marketer
“The easiest and best A/B testing tool I’ve used. Unbelievably easy to set up, seamless editor, and much better user experience than other apps. Everything we needed, Stellar has.”
Founder, ThrillX
“We never found a good replacement for Google Optimize until we found Stellar. Super easy to install and get campaigns running. We’re running half a dozen campaigns with plans for plenty more.”
Technical Director, Digital Relativity
A plan for every traffic level.
Start free in the Sandbox. Plans scale with monthly tested users, so a site with 20k visits does not pay for enterprise volume.
For one site or a handful of them, with up to 50k monthly tested users included.
- 50k MTU included, then $2 per extra 1k, billed as you go
- Unlimited experiments, variants, goals and domains
- Heatmaps, funnels and AI insights
- Autopilot, advanced targeting and dynamic keyword insertion
- Team seats and priority support
For a solo marketer running steady tests on one site.
- 25k MTU per month
- 2 active experiments, 3 variants each
- Visual editor and real-time analytics
- 3 domains, 180-day data retention
For agencies and brands with several high-traffic sites.
- 250k MTU included, then $1.50 per extra 1k
- Everything in Pro, at higher volume
- Same-day priority support
- Dedicated onboarding and migration help
Frequently asked questions.
Answers to what marketers ask before their first test. Still unsure? Use the chat in the corner and a human replies.
Read the docsWill Stellar work on my website?
Yes. Stellar works on sites that let you add a JavaScript snippet, including Shopify, WordPress, Webflow, Wix, Framer, and custom-built sites. You can create visual experiments without code, then use custom JavaScript and CSS when you need more control.
How is Stellar installed?
Add your unique Stellar snippet once in your site’s global head so it loads on the pages you want to test. Direct installation is recommended for the fastest variant delivery and anti-flicker support. Google Tag Manager also works, but it loads later and is less suitable for above-the-fold visual changes. Use one installation method, not both.
Will Stellar affect my site speed?
Stellar is designed to keep its client-side footprint small and is delivered through a CDN. For visual experiments, anti-flicker can briefly hide the page while a variant is applied; use it with a direct head installation when preventing a flash of original content matters, and disable it for event-only tracking or GTM installs.
How does Stellar work with privacy and cookie consent?
Stellar does not require browser cookies to assign visitors to experiments or track experiment activity. You stay in control of when the snippet loads: if your policy requires consent first, configure your consent platform or tag manager to load Stellar only after that condition is met. Your organization remains responsible for its consent and privacy obligations.
Can I use Stellar with Google Analytics 4?
Yes. Stellar has a native GA4 integration that sends experiment conversion events through Google’s Measurement Protocol. Connect your Measurement ID and API secret in Stellar, then use the experiment and variant parameters in GA4 reports and explorations.
What is an MTU and how does billing scale?
An MTU is a unique visitor who participates in an experiment during a calendar month, not every session or page view. Plans include a monthly MTU allowance. Pro includes 50k MTU and Scale includes 250k; usage-based billing can cover traffic above those allowances instead of requiring an immediate plan change.
Launch your first test today.
Add the snippet, open the editor on your page and ship a test before your next ad budget review. Free to start, and the sandbox never expires.