You've probably tried Fusion already, or you're weighing it up. It does something most AI builders don't: it opens the app your team already runs, lets a designer change it on a canvas, and hands engineering a pull request. If you searched "Builder.io alternatives" and got a page of CMSs, that's Builder's other product. This post is about Fusion.
Below is what Fusion does, where it stops fitting, and the tools people move to, starting with the one closest to it in shape.
What Fusion does
You connect a GitHub, GitLab, Bitbucket or Azure DevOps repository, tell Fusion how to install and start the app, and paste in your .env if it needs one. Builder runs the app in its cloud. You edit visually or by prompt, and Send PR opens a pull request with only the changed code.
There are three commit modes: direct commits to the base branch, draft pull requests and ordinary pull requests. Check which one a project is on before a designer starts clicking.
Why teams look elsewhere
The framework list is short. React, Vue, Svelte and Angular are supported, and Builder says more are in development. That rules out a Laravel or Rails app today, along with anything whose pages are rendered by a Go or Python server.
The bill grows with the team. Fusion's pricing is per seat. The free tier gives you 60 agent credits a month. Pro is $24 per user and Team is $40, with extra credits on Pro at $25 per 500. Put a PM, a designer and one developer on Team and you're at $120 a month before anyone runs out.
It writes to your repo. A .builderrules file appears once you connect and make changes. Branches start from main, and picking another base branch is an Enterprise setting. Neither is a dealbreaker. Your engineers will notice both.
Refinar
Best for: a PM or designer who doesn't code, on a GitHub app outside Fusion's four frameworks or one where the backend matters.
Stack range is the first difference. Refinar has adapters for Next, Vite, Astro, Nuxt and Angular on the frontend, and for apps served by Laravel, Django, Rails, Go or Rust, plus static sites and monorepos. It pulls the app from GitHub and runs all of it in a cloud sandbox, so the preview is talking to the same services production does.
Pricing is the second. Every plan, from $50 a month, covers 20 teammates, so adding the designer doesn't add a seat (pricing). Your repository gets a branch and a draft pull request. No rules file, no runtime config.
Where Refinar is weaker: there's no design canvas to drag things around on. You write what should change, or click the element in the live preview you mean, and the agent makes the edit in front of you. It also supports GitHub alone, so a team on GitLab or Azure should stay where it is. On safety, Refinar flags any write to a connected service and pauses for approval. A change to sign-in, payments or customer data won't go out on its own. Refinar builds the safe part and hands the remainder to a developer, either yours or one at Refinar, who on business days takes it on within 4 hours (how it works).
JetBrains Matter
Best for: a frontend team that wants the idea for free and doesn't mind early access.
Matter is JetBrains' version, free while its early access programme runs. PMs and designers prompt changes in a cloud mirror of your repo, pull colleagues in with @mentions and hand off a GitHub pull request. Like Fusion it's frontend-first, since the preview needs a dev server such as Vite. It connects with a personal token or SSH key, and JetBrains can end the programme at any time. The full picture is in JetBrains Matter alternatives.
Onlook
Best for: a designer who wants a canvas they can host themselves.
Onlook is open source under Apache 2.0, the only one here that is. Run it locally or use the hosted version, and it edits the underlying code as you move elements around. It's happiest on Next.js with Tailwind. The hosted app still has a waitlist, and no pull request flow is documented, so expect a developer to handle the handoff.
v0
Best for: Next.js, already on Vercel.
If your Fusion project is a Next.js app deployed on Vercel, v0 is the shortest jump. It imports the repo and opens pull requests that respect branch protection. Off Vercel it gets harder, because it wants a Vercel project attached and its preview only reads Development variables. Can v0 import an existing GitHub repo goes through the details.
Cursor or Claude Code
Best for: changes an engineer will make anyway.
Fusion earns its seat price by letting non-developers work in the codebase. If the person making this change is an engineer, that part doesn't apply. An agent in the repository does the same job with no hosted runtime, no seats and no files added for the platform.
Which one should you pick?
- Outside Fusion's four frameworks, or the backend matters: Refinar.
- A frontend team happy on early access: JetBrains Matter.
- A canvas you can host yourself: Onlook.
- Next.js on Vercel: v0.
- The person making the change writes code: Cursor or Claude Code.
- React, Vue, Svelte or Angular on GitLab or Azure, with a design team that thinks in canvases: stay on Fusion.
Figma teams have their own version of this question, covered in Figma Make alternatives. And before anyone outside engineering ships, agree on what non-developers can change and what still needs a developer.
If your stack is one Fusion can't open, point Refinar at the repository and see whether the whole app comes up in the preview.