OpenPencil

OpenPencil is a free, open-source editor for Figma-compatible interface design and for embedding a canvas inside other software. It is strongest for Figma users, local-first teams, and developers building focused editing workflows. The broad design and automation set is impressive at no cost, but the absence of prototyping and developer handoff makes it a poor fit for teams that need those delivery stages.

Overview

OpenPencil reads and writes native Figma .fig files and supports copy-and-paste in both directions. That makes it a practical companion to Figma rather than an isolated replacement, especially when a team needs to move existing files between tools. Its local-first model requires no account or server, while real-time collaboration connects peers directly through WebRTC. This is attractive for privacy-conscious work and quick sessions, though it also means collaboration depends on direct peer connections.

The product doubles as a toolkit. Its Vue SDK is aimed at teams embedding a focused canvas in an internal workflow, template editor, or AI-assisted product. That is a meaningful advantage for software makers; a designer seeking only a standalone editor may gain little from the SDK.

Key features

Design and file handling

Vector drawing, rich text, components, variables, multi-page documents, and flexbox and CSS Grid auto-layout cover serious interface-production needs. Export targets include PNG, JPG, WEBP, SVG, and Tailwind JSX, with raster scales from 0.5× through 4×. The formats suit both visual assets and developer-oriented output, although there is no developer-handoff capability or UI animation support.

AI and automation

The assistant provides more than 90 tools for editing and analysis and can connect to Anthropic, OpenAI, Google AI, or OpenRouter. OpenPencil charges no subscription or backend fee for this feature: you supply a provider key and connect directly to that provider. That keeps the application cost low but puts model access and usage billing under your control. An MCP server works with Claude Code, Cursor, Windsurf, and other MCP clients over stdio or HTTP. The CLI can inspect, export, and analyze .fig files and return machine-readable JSON, making repeatable or scripted workflows considerably more practical.

Privacy and collaboration

Peer-to-peer WebRTC collaboration works without accounts and sends design data between participants instead of through a central service. The local-first approach also means local chat history is not synchronized to the cloud or backed up. For automation, the MCP HTTP server enables authentication by default, listens on 127.0.0.1 by default, limits file access to a configured root, and rejects symlink escapes. Those safeguards are useful when exposing tooling, but teams still need to manage their own provider keys and local data.

Pricing

OpenPencil has one plan: Free at free. It includes a no-account, no-subscription editor under the MIT license, with real-time collaboration and design-system support. There is no free trial because the product is already free, and no paid tier or seat charge is described. This is the natural choice for individual designers, open-source projects, and teams comfortable operating their own AI provider connections. It offers no prototype capabilities and no developer handoff, so a zero price does not remove the need for another tool in a full product-design process.

Platforms

OpenPencil is offered on Android, iOS, Linux, macOS, Windows, and the web, with API access. Desktop binaries cover macOS, Windows, and Linux; the macOS build is signed and notarized. On phones, the web app can be installed as a progressive web app and uses a touch-oriented interface. The primary experience is web desktop, while the broad platform list helps distributed teams use the same editor across devices.

Who it's for

Choose OpenPencil if you need Figma file interchange without committing every workflow to Figma, want account-free peer collaboration, or are building a custom canvas into another product. It is especially compelling for developers who can take advantage of the Vue SDK, CLI, and MCP integrations. Look elsewhere if interactive prototypes, animations, or formal developer handoff are central requirements, or if your team wants cloud-synchronized chat history and a managed AI bill.

Pros and cons

• Pros: Native Figma file support and copy-paste ease migration; broad layout and component tools handle substantial UI work; five export formats plus Tailwind JSX cover design and implementation needs; 90-plus AI tools and MCP/CLI automation suit technical workflows; peer-to-peer collaboration requires no account; MIT licensing and the free plan remove subscription and seat costs.
• Cons: No prototyping, animation, or developer-handoff features; AI requires your own provider key and direct provider billing; local chat history is not cloud-backed up; WebRTC collaboration relies on peers connecting directly rather than a central workspace.

Alternatives

Fluid UI is a better fit when you want a freemium product with a free lifetime account, trial access, and paid Solo capacity. Choose Framer instead for a freemium web-design service with a free domain, 1 GB bandwidth, CMS collections, and AI credits. UXPin suits teams prioritizing prototype work and AI credits, with a limited free plan after its 14-day trial. Justinmind offers a free editor plan with one project, unlimited screens and viewers, and interactive input forms. MasterGo is worth considering for a managed freemium workspace with draft-file, member, page, and layer limits. Mockplus provides a free-forever Basic plan for 10 users, 10 active projects, and unlimited designs. ProtoPie is the alternative when cloud prototypes and scene-based interaction matter. FlowMapp is oriented toward site planning, with a free one-project plan and a paid Pro tier.

For more options, browse Game UI Design Software.

Verdict

OpenPencil is an excellent choice for Figma-compatible design on a zero-subscription, local-first foundation, particularly for open-source users and teams embedding a custom editor. Choose it for file interoperability, automation, and account-free collaboration. Choose another product when prototyping, animation, developer handoff, or managed cloud history is more important than control and flexibility.