Eleventy (11ty)
Simple, flexible, and fast static site generator. Eleventy works with 11+ template languages (Markdown, Nunjucks, Liquid, HTML, JavaScript, etc.) and outputs plain HTML with zero client-side JavaScript by default. Extremely fast builds (no bundler required), flexible data cascade, and no framework lock-in. Used for high-performance sites where output HTML quality and build speed matter. Maintained by Zach Leatherman, sponsored by companies including Netlify.
Score Breakdown
⚙ Agent Friendliness
🔒 Security
MIT open source. Static HTML output with no server-side execution in production. No credentials required. Minimal dependency footprint compared to React-based SSGs.
⚡ Reliability
Best When
You want maximum flexibility in template languages, zero-JavaScript output by default, and blazing-fast builds without framework opinions.
Avoid When
You need React, a large plugin ecosystem, complex data fetching patterns, or an opinionated full-stack framework — Next.js, Astro, or SvelteKit are better.
Use Cases
- • Build fast documentation or marketing sites that output pure HTML with zero JavaScript payload by default
- • Generate static pages from JSON/YAML data files using Eleventy's data cascade for agent-driven content generation
- • Create template-agnostic sites that mix Nunjucks, Markdown, and JavaScript templates in the same project
- • Build sites with excellent build performance — Eleventy's build speed is among the fastest SSGs for large content volumes
- • Generate HTML emails or other structured documents from templates using Eleventy's flexible template system
Not For
- • Applications needing React component ecosystem — Eleventy is for static HTML output; use Next.js or Gatsby for React-based sites
- • Sites needing client-side interactivity — Eleventy outputs static HTML; JavaScript must be added manually
- • Teams wanting a batteries-included framework — Eleventy is intentionally minimal; routing, image optimization, and other features need explicit setup
Interface
Authentication
No auth — static site generator. Private sites require hosting-level auth.
Pricing
MIT open source. Free forever. Maintained by Netlify via sponsorship.
Agent Metadata
Known Gotchas
- ⚠ Eleventy's data cascade (global data → directory data → template data) can produce unexpected results — agents must understand which data layer takes precedence for each template
- ⚠ Eleventy 3.x is ESM-only — projects using CommonJS (require()) must migrate to ESM or use older Eleventy versions; this is a significant breaking change from 2.x
- ⚠ Collections in Eleventy are built from file globs — agents adding content to new directories must verify glob patterns in eleventy.config.js include the new paths
- ⚠ Pagination in Eleventy generates multiple output files from one template — agents managing paginated content must understand Eleventy's pagination tag system
- ⚠ Incremental builds (--incremental) have caveats — changes to shared layouts or data files don't always invalidate all dependent pages; full rebuild needed after global changes
- ⚠ Eleventy's template language auto-detection based on file extension can be overridden — agents setting explicit template engines via eleventyConfig.setTemplateFormats() must match their file extensions
Alternatives
Full Evaluation Report
Detailed scoring breakdown, competitive positioning, security analysis, and improvement recommendations for Eleventy (11ty).
Scores are editorial opinions as of 2026-03-06.