Eleventy vs Astro: the CTO decision guide for content sites, docs, and marketing pages

Eleventy vs Astro: the CTO decision guide for content sites, docs, and marketing pages

Astro sits around 2 million weekly downloads, and Eleventy sits around 200,000, per a 2026 SSG roundup from PkgPulse Best Static Site Generators 2026. The download gap matters less than the operating model gap. Astro pushes a component workflow and “islands” hydration. Eleventy pushes templates and plain HTML.

Most CTOs I talk to don’t fail on the tool choice. Teams fail on the second-order effects: build times in CI, who can ship changes, and how painful migrations feel two years later. The Eleventy vs Astro decision is really a bet on how your org wants to build and maintain content software.

Eleventy vs Astro: what each tool is, and what it ships

Eleventy (11ty) is a JavaScript static site generator that turns templates and content into HTML. Astro is a content-focused web framework that also outputs static HTML, but it’s built around components and selective hydration.

A quick timeline helps set expectations:

• Eleventy started in 2018, and Astro started in 2021, per a 2026 comparison by Gautam Khorana Astro vs Eleventy (2026).
• Astro’s core pitch is “ship zero JavaScript by default” and hydrate only interactive parts, described in PkgPulse’s 2026 guide Best Static Site Generators 2026.

Both tools can produce the same end result: a fast content site on a CDN. The differences show up in the build pipeline and the authoring model.

Eleventy core capabilities

• Template flexibility: Eleventy supports many template languages, including Liquid and Nunjucks, and you can mix them, per CloudCannon’s comparison Eleventy (11ty) vs. Astro.
• Plain HTML output: Eleventy produces static HTML without a framework runtime.
• Performance focus: Eleventy positions itself as “best-in-class build performance” and publishes benchmark tables in its docs Eleventy Performance.

Astro core capabilities

• Component-first templating: Astro uses .astro components for most templating, per CloudCannon Eleventy (11ty) vs. Astro.
• Multi-framework islands: Astro can embed React, Vue, Svelte, and others, and hydrate only the interactive parts, per PkgPulse Best Static Site Generators 2026.
• Asset pipeline out of the box: Astro handles bundling CSS and JavaScript without manual setup, per Astro’s migration guide Migrating from Eleventy.

A framing I’ve used with leadership teams that actually sticks: Eleventy is a content compiler. Astro is a content compiler plus a component system.

Eleventy vs Astro performance: build times, installs, and CI cost

Static site performance shows up in two places. Users feel it in Core Web Vitals. Teams feel it in build time and install time.

Build time benchmarks: what the numbers say

Eleventy’s docs cite a July 2022 benchmark building 4,000 Markdown files: Eleventy at 1.93s and Astro at 22.90s Eleventy Performance. Benchmarks age, but the shape of the result is still useful. Eleventy does less work per page.

A more “real world” test from 2024 used 770 posts and about 2,550 built pages. The author measured 10 builds and got Eleventy at 4.29 seconds and Astro at 10.07 seconds Inexactly benchmarking Eleventy vs Astro build times. That gap turns into CI minutes and slower feedback loops.

A practical rule I use:

• If your marketing site builds on every merge, and you merge 50 times a day, a 6 second delta costs 5 minutes a day in wall clock time. Queue time makes it worse.
• If your docs site builds on every doc PR, and you run 30 doc PRs a week, build time matters less than authoring friction.

Install time and dependency weight: supply chain and developer time

Tom MacWright compared fresh installs and counted 246 dependencies for Astro and 116 for Eleventy. He also measured 87.9MB vs 14.6MB in dependency weight Eleventy - macwright.com. A smaller dependency graph means less audit surface and faster cold installs.

Eleventy’s own docs cite a node_modules weight of 34MB for Eleventy and 169MB for Astro, plus install times of 5.81s vs 12.52s in a 2023 review Eleventy Performance. Install time hits every new laptop, every CI cache miss, and every ephemeral build runner.

Runtime performance: both can be fast, but Astro makes interactivity easier to control

Both tools can ship near-zero JavaScript pages. The difference shows up the moment product asks for interactive UI.

• Eleventy teams often bolt on client JavaScript by hand. That can work fine, but someone has to police bundle size and hydration patterns.
• Astro teams can keep most pages static and hydrate only a search box, pricing calculator, or docs sidebar.

PkgPulse calls out Astro’s islands model and “zero JavaScript by default” behavior Best Static Site Generators 2026. That default is a real guardrail, especially for marketing sites that tend to accrete widgets over time.

Which scales better: 50 pages, 5,000 pages, or 50,000 pages?

Scale isn’t just page count. Scale is page count plus content model complexity plus contributor count.

Small sites: Eleventy wins on simplicity and speed

For a 50-page blog or a small marketing site, Eleventy stays hard to beat. Gautam Khorana’s 2026 comparison calls Eleventy “the cleanest path” for a small content site with Markdown and Liquid Astro vs Eleventy (2026).

I’ve seen this pattern a lot in startups with 5 to 20 engineers. Marketing wants a fast site. Product doesn’t want a second React app to babysit. Eleventy gives you a folder of content and templates, and you ship.

The catch is consistency work. Someone has to own RSS, <head> tags, and asset bundling. Wavebeem called out the tedium of keeping RSS and consistent <head> tags, even while preferring Eleventy’s simplicity Becoming an Astro-not.

Medium sites: Astro starts to pay off with components and typed content

Once you add repeated UI patterns, Astro’s component model saves time. CloudCannon notes Astro components offer reusable UI without a client runtime by default Eleventy (11ty) vs. Astro.

Typed content is the other inflection point. Sandro Roth described moving to Astro content collections with Zod schema validation for type safety Migrating my site from Eleventy to Astro. That matters when content becomes a product surface, like a docs portal with versioned APIs.

A real scenario:

• A B2B SaaS has 600 docs pages, 120 changelog entries, and 40 landing pages.
• The team wants a shared “callout” component, a version badge, and a code block component.
• Astro lets a platform or docs team ship those components once, and content authors reuse them.

Very large sites: page count forces you to care about incremental builds and hosting

PkgPulse claims Eleventy and Next.js with ISR are viable for 50,000+ pages, and it notes Astro lacks native ISR, even as Astro adds more server features Best Static Site Generators 2026. Gautam Khorana also argues Astro scales past a few hundred pages better due to its content layer and rebuild story Astro vs Eleventy (2026).

Here’s what I’ve learned the hard way: large sites don’t break for the same reason. They break for different reasons depending on your pipeline.

• CI timeouts and memory spikes.
• Content fetch limits from headless CMS APIs.
• Preview builds that take 20 minutes, so editors stop using previews.

Eleventy supports incremental builds, but a 2024 benchmark notes limits in CI usage and pagination cases Inexactly benchmarking Eleventy vs Astro build times. Astro has its own caching and build strategies, but you still need to design for scale.

If your org plans programmatic SEO at scale, treat the generator as one part of a pipeline. You’ll also need content QA, redirects, canonical tags, and monitoring.

The CTO decision matrix: Eleventy vs Astro across people, risk, and time

Most comparison posts stop at features. CTOs need a decision model that includes hiring, security, and ownership.

Here’s a link-worthy element you can reuse.

The SSG Fit Matrix (CTO edition)

Score each row 1 to 5 for your org. Add the totals. Then argue about the top two rows, not the total.

CloudCannon highlights Eleventy’s template decoupling as a migration advantage Eleventy (11ty) vs. Astro. Astro’s opinionated component model can raise switching costs, but it also reduces internal fragmentation.

A quotable definition I use with exec teams:

Eleventy is a fast HTML compiler. Astro is a component system that compiles to fast HTML.

Leadership reality: tool choice sets your ownership model

Eleventy works best when one team owns the site end to end. That team can keep templates clean and avoid plugin sprawl.

Astro works best when multiple teams ship content and UI. The component model becomes a contract. A platform team can publish a small internal component library and keep marketing and docs consistent.

If you want to make that ownership visible, track it. Our internal guide to a DORA-focused engineering metrics dashboard pairs well with this decision. Track lead time for content changes and failure rate for deploys.

CTO recommendations: how to choose, migrate, and run the work

Most orgs can switch between Eleventy and Astro in days, not months. Stephan Max said his migration took “a couple of hours” and praised both tools’ docs Why I Switched from Eleventy to Astro. Astro also publishes a direct migration guide Migrating from Eleventy.

The hard part isn’t the code. The hard part is content workflows and ownership.

Immediate actions (next 2 weeks)

1. Measure build and preview time. Run 10 clean builds in CI and record p50 and p95. Use Piper Haywood’s method as a template, and keep the page count in the notes Inexactly benchmarking Eleventy vs Astro build times.
2. Inventory interactivity. List every interactive element you need in the next 6 months. Count them. A site with 2 widgets is a different beast than a site with 30.
3. Audit dependency weight. Compare node_modules size and dependency count in a fresh install. Use MacWright’s numbers as a reference point Eleventy - macwright.com.
4. Pick a content source of truth. Decide between Markdown in repo, headless CMS, or API-driven content. Both tools support all three, per Astro’s migration guide Migrating from Eleventy.

If you want one place to track the decision and the risks, use Command Center as your system of record for tech choices, migrations, and incident risk.

Policy framework (how to stop the site from becoming a side quest)

1. Ownership. Name a single DRI for the site build pipeline and deploys. Rotate the DRI quarterly.
2. Change control. Require previews for any change that touches navigation, SEO tags, or redirects.
3. Dependency policy. Set a rule for adding plugins and integrations. A simple rule works: one new dependency needs one owner.

Our playbook on architecture governance that doesn’t slow teams down fits here. Model the site as a product with interfaces, not as a pile of pages.

Architecture principles (how to keep performance and velocity)

1. Static by default. Keep pages static unless a clear user need demands runtime.
2. Islands for interactivity. If you pick Astro, standardize on one UI framework for islands. Don’t allow three.
3. Content schemas. If you pick Astro, use content collections and schemas for any content that drives routing or SEO. Sandro Roth’s Zod mention is the right instinct Migrating my site from Eleventy to Astro.
4. Build budgets. Set a build time budget and treat regressions like incidents. Use our incident postmortem template when build time jumps 2x.

For vendor choices like headless CMS or search, run the decision through our Build vs Buy Matrix. Static sites still have vendors, and lock-in shows up in content APIs.

Bigger picture: static sites are now part of your supply chain

Marketing sites and docs sites used to sit outside “real engineering.” That split is gone. SEO pages drive pipeline. Docs drive support load. A broken deploy can block a product launch.

Astro’s growth and component story make it attractive for orgs that want one content platform across teams. Eleventy’s simplicity and smaller dependency graph make it attractive for orgs that want low risk and low overhead. PkgPulse frames the choice well: pick based on what you’re building, not what’s popular Best Static Site Generators 2026.

One question I’d put on the staff meeting agenda: who owns the content build system when the marketing site deploy fails at 2 a.m.?

Sources

1. Best Static Site Generators 2026 — PkgPulse Guides
2. Astro vs Eleventy (11ty) (2026) — Which Static Site Generator Wins?
3. Eleventy - macwright.com
4. Eleventy (11ty) vs. Astro | CloudCannon
5. Why I Switched from Eleventy to Astro
6. Migrating from Eleventy - Astro Docs
7. Becoming an Astro-not
8. Migrating my site from Eleventy to Astro - Sandro Roth
9. Inexactly benchmarking Eleventy vs Astro build times
10. Performance — Eleventy