Silex

Silex is a free, libre visual website builder maintained by Silex Labs, a French non-profit. It lets designers and developers create websites visually using a GrapesJS-based drag-and-drop editor, then export clean, standards-compliant HTML and CSS that can be hosted on any platform — no proprietary formats, no forced hosting, no vendor lock-in.

At its core, Silex bridges the gap between no-code visual design and real web standards. You design visually, but every output is plain HTML, CSS, and JavaScript that you own entirely. The tool integrates with headless CMS platforms (WordPress, Strapi, Squidex, Supabase) via GraphQL, and pairs with 11ty (Eleventy) for generating full static sites with dynamic CMS-driven content.

Silex is structured as a meta-monorepo of 24 independently versioned packages, including the core Node.js library, a plugin system, GrapesJS extensions for fonts, symbols, data sources, CSS variables, and an upcoming Tauri-based desktop application with an integrated MCP server for AI-assisted design. The platform is free forever under AGPL, with all features included and no premium tier.

With over 23,000 accounts created and 1,000+ weekly users, Silex has been community-maintained since 2009. It targets web agencies, WordPress developers, and freelance designers who need Webflow-level visual control without the subscription costs or proprietary formats.

What You Get

• GrapesJS-based visual editor — Drag-and-drop page builder with live HTML, CSS, and JS editors enabling pixel-perfect layout without writing code
• Static HTML/CSS export — Clean, standards-compliant static output that can be hosted on Netlify, GitHub Pages, S3, or any web server
• CMS integration via GraphQL — Bind components to WordPress, Strapi, Squidex, Supabase, or any custom GraphQL API to pull dynamic content into static pages
• 11ty static site generation — Generate full static sites from Silex templates and deploy through CI/CD pipelines with complete build control
• Self-hosting options — Run Silex via Docker, Node.js (npx), CapRover, YunoHost, or Elest.io with full data ownership
• Plugin system (JS/TS) — Extend the editor and server with custom plugins using an environment-agnostic plugin API and official starter template
• SEO and meta tag controls — Configure per-page title, meta description, Open Graph tags, and structured data directly in the visual editor
• CSS Variables manager — Define and manage CSS custom properties (design tokens) across the site for consistent branding and easier redesigns
• Advanced Selector Manager — Apply compound CSS selectors, manage styles at class and ID level, with compound selector support like .a > .b
• Desktop app with AI/MCP support — Offline-first Tauri-based desktop application exposing an MCP server so any compatible AI tool (Ollama, Claude Code, Goose) can design pages via prompts

Common Use Cases

• Agencies building static client sites — Web agencies use Silex to design and export clean HTML/CSS for clients, skipping SaaS subscriptions and giving clients full ownership of their site code
• WordPress developers replacing theme layers — WordPress developers connect Silex to the WP GraphQL API to design modern, fast static frontends while pulling live content from the existing CMS
• Freelancers selling reusable site templates — Freelancers build CMS-connected Silex templates for verticals (restaurants, law firms) and reuse or sell them across clients with zero code duplication
• No-code builders who outgrew Wix/Squarespace — Power users wanting full CSS control, static output, and no subscription costs migrate to Silex as a fully open alternative to Webflow
• Educators teaching web fundamentals — Schools use Silex to teach HTML, CSS, and JAMstack concepts through a visual interface that outputs real, transferable web skills
• Developers experimenting with AI-driven web design — Developers use the MCP server in Silex Desktop to automate layout generation and site building using local AI models

Under The Hood

Architecture Silex is organized as a meta-monorepo of 24 independently versioned git submodules, each living in its own repository with its own issues, releases, and pull request history. A custom topological dependency sorter enforces correct build order across packages by resolving internal workspace references into a directed acyclic graph. Concerns are cleanly separated: GrapesJS editor plugins handle all visual editing, the silex-lib Node.js core manages storage and server connectors, the Rust/Tauri desktop shell exposes an MCP server for AI integration, and the 11ty layer handles static output. This architecture makes each concern independently replaceable and allows contributors to work on a single package without understanding the full system. The trade-off is coordination overhead around submodule references and release synchronization.

Tech Stack The visual editing layer is built on GrapesJS, a JavaScript WYSIWYG framework extended through Silex’s own plugin system (silex-plugins). The server is Node.js 16+ using ES modules and Yarn 1.x Workspaces for dependency management. The desktop application is built with Rust and Tauri v2, providing cross-platform (Windows, macOS, Linux) native packaging and an MCP server endpoint at http://localhost:6807/mcp. CMS data binding uses GraphQL against Strapi, WordPress, Supabase, and generic APIs. Static site generation uses Eleventy (11ty). Deployment artifacts include Docker images, an npx CLI, and one-click platform integrations for CapRover, YunoHost, and Elest.io. Build orchestration uses Yarn Workspaces with a custom topological build script; releases follow a canary → stable tag workflow that drives CI deployments.

Code Quality The meta-repo scripts are written as modular ES module utilities with clear responsibilities — dependency graph resolution, build ordering, changelog generation, and release automation — and the release script employs set -euo pipefail for robust error handling. The project enforces a discuss-before-coding contribution policy and uses Husky for pre-commit hooks. Coding standards are documented (BEM CSS, GrapesJS CssComposer, Flexbox-only layout). The test script runs a consistency checker for internal dependencies rather than unit tests, and individual package testing lives in each submodule repository. The meta-repo layer itself is appropriately thin; meaningful code quality assessment requires examining individual package repositories like silex-lib or grapesjs-data-source.

What Makes It Unique Silex’s defining characteristic is that it combines a professional-grade WYSIWYG editor with CMS-agnostic dynamic data binding and static output — a combination commercially offered only by Webflow, but here implemented entirely as free/libre software under AGPL by a non-profit. The emerging MCP server integration enables local AI models to directly control the visual editor, which is genuinely novel territory for open-source website builders. The CSS Variables manager and Advanced Selector Manager bring design system workflows (design tokens, compound selectors) normally found only in paid tools. The AGPL license and non-profit governance model with transparent finances on OpenCollective provide a structural guarantee against the tool being commercialized or abandoned to investors.

Self-Hosting

Silex is licensed under the GNU Affero General Public License v3.0 (AGPL-3.0), a strong copyleft license. For self-hosters, this means you can run, modify, and distribute Silex freely — including for commercial client work — as long as any modifications to the Silex source code itself are shared under the same license if you distribute them or offer them as a network service. If you use Silex internally to build client websites and export the output HTML/CSS, that output is entirely yours and is not affected by the AGPL. The copyleft clause applies to modifications to Silex itself, not to sites built with it.

Running Silex yourself requires a Node.js 16+ environment or a Docker-capable host. Storage connectors (GitLab, local filesystem) need to be configured, and by default the online version uses GitLab for project storage. The npx route is the fastest way to start: a single npx @silexlabs/silex command launches the editor at localhost:6805 with no prior installation. For production self-hosting, CapRover and YunoHost provide one-click deployment with automatic SSL. The desktop app (currently in alpha) adds offline-first operation with local file storage and no account requirement. Operational burden is modest for the editor itself; the bigger responsibility is configuring and maintaining any CMS or storage backend you connect to it.

Compared to the hosted version at v3.silex.me, self-hosting gives you full data ownership and removes any dependency on Silex Labs infrastructure, but you are responsible for uptime, backups, and upgrades. There is no paid enterprise tier, no SLA, and no managed upgrade service — the community forum and GitHub issues are the primary support channels. The non-profit model means there is no commercial cloud upsell, and all features are available equally in the self-hosted version. Users who want managed infrastructure can use third-party platforms like Elest.io, which offer hosted Silex with managed operations.