The Sketch alternative where the design runs.
Sketch defined a decade of interface design on the Mac. Prototyper is an AI-native canvas in any browser, on any operating system, where your agent builds the design as a running React screen and the whole team works on it together.
Last reviewed
What Sketch does well
Native Mac craft
A fast, focused, genuinely native app. People who love Sketch love how it feels, and they are right to.
Mature vector tooling
Components, libraries and precise vector editing refined over a decade of interface work, with real-time collaboration in the Mac app.
Local files and AI on your terms
Work offline in local documents if you want, and its local-only MCP server lets agents like Claude Code read and change those documents on your Mac.
Where Prototyper is different
The output runs
A Sketch artboard is a picture of a product. A Prototyper screen is React and TypeScript you can click, type into and commit to GitHub.
Any browser, any machine
Full editing happens in the browser. Designers on Macs, PMs on Windows and engineers on Linux all work the same canvas.
Agents build, not just automate
Claude Code, Codex or Cursor connects over MCP and writes the screen’s code on the canvas, instead of scripting a design file.
Bring your own agent
Your own agent runs on the plan you already pay for. A built-in agent is there for quick edits.
Side by side
| Prototyper | Sketch | |
|---|---|---|
| Real running output (React) | Yes | No |
| Full editing in the browser, any OS | Yes | View, inspect, comment |
| Real-time multiplayer editing | Yes | Yes |
| External AI agents over MCP | Build screens in code | Local, on the Mac |
| Precise vector illustration tooling | No | Yes |
| Native Mac application | No | Yes |
Checked against Sketch's official pages on 6 October 2026; tell us if something is out of date.
Which one to pick
Pick Sketch when
- Your design team works on Macs and loves a native app
- Vector illustration, icons and precise craft are the job
- You want local files and offline work
- You want agents to automate work inside design files
Pick Prototyper when
- Your team uses Windows, Linux or a mix of machines
- You want an AI-native tool where the design is running code
- You want Claude Code, Codex or Cursor to build the screens
- The design should end as a pull request, not a spec
A picture of a product, or the product
Sketch produces artboards: precise, considered pictures of software. The craft is real, and for years it was the best way to specify an interface. But a specification still needs builders. Every artboard waits for an engineer to translate it, and every translation drifts a little from what the designer meant.
On Prototyper the design and the software are the same object. You sketch or describe a screen, an agent builds it as running React on the canvas, and refinement happens on the real thing. What the team approves is code, ready to commit.
The platform question
Sketch made a principled bet on the Mac, and the app is better for it. Editing happens in the Mac app; the web app lets anyone on any platform view, inspect and comment. For a design team on Macs that is enough. For a product team with Windows and Linux machines in it, only some people can change the design.
Prototyper is browser-native. The same multiplayer canvas opens on any modern machine with editing included, so a team on Windows, Linux and macOS works one surface. Agents connect over MCP from wherever they run.
Where the AI sits
Sketch has taken a careful route to AI. Its MCP server is off by default, runs locally inside the Mac app, and lets clients such as Claude Code, Codex or Cursor read and modify Sketch documents through the Sketch API. It suits automation: exporting assets, auditing a design system, generating screens from templates.
Prototyper is AI-native in a different sense. The agent’s job is to build the product screen itself in code, next to your sketches, and to revise it when you point at what is wrong. Your own agent connects over MCP from any machine, and the built-in agent covers quick changes.
Where each tool earns its seat
For icon work, illustration and precise vector craft, Sketch remains an excellent instrument, and Prototyper does not compete for that seat. The same goes for teams who want offline, local files they control.
The seat we claim is product work: screens, flows and prototypes meant to become software, shaped by a team that is not all on Macs.
Moving over, or running both
Keep Sketch for vector craft and brand assets if that is where it serves you; plenty of teams will. Product screens are the work to move. There is no .sketch import: drop a screenshot onto the canvas, redraw it roughly, or describe it, and the agent builds the running version.
A practical first step is one active flow. Rebuild your onboarding or checkout in a workspace, review it with the team on the live canvas, and compare that cycle with your current one. The canvas is free to start, reviewers join as free viewers, and your own agent runs on the plan you already pay for.
Frequently asked questions
- Is there a Sketch alternative for Windows?
- Prototyper runs in any modern browser on Windows, Linux or macOS, with full editing rather than a viewer. There is nothing to install.
- Can I edit Sketch files in the browser?
- Sketch’s web app lets you view, inspect and comment on documents from any platform; editing happens in the Mac app. Prototyper does not open .sketch files.
- Does Sketch have AI?
- Sketch has a local MCP server that lets AI clients read and modify documents in the Mac app. Prototyper’s agents write the product screens themselves as running React code.
- Do I need to know how to code?
- No. You direct with sketches, selections and plain language; the agent writes the code. People who read code can open any file.
- Is Prototyper a Sketch replacement?
- For product screens and prototypes, yes. For vector illustration and icon craft, Sketch still earns its seat, and many teams keep it for exactly that.
Sources
- Sketch: What is Sketch?, accessed
- Sketch: Real-time collaboration, accessed
- Sketch: MCP server, accessed
See it against your current tool.
The fastest way to compare is to put an agent on the canvas and watch it build. Free to start, no credit card.