--- title: "Features" description: "Static caching, built-in SEO and GEO, a block editor, an AI assistant and security: every feature of Éclair, the fast CMS that needs no database." url: "https://eclaircms.org/en/features" lang: "en" author: "Thierry Gustin" published: "2026-10-30" updated: "2026-10-30" --- # Features > **Key takeaways** — Éclair is a fast CMS that comes complete out of the box: automatic static caching (Lighthouse 100), built-in SEO and GEO (JSON-LD, sitemap, llms.txt, Markdown versions, rules for 30 AI bots), a 17-block editor, an optional AI assistant, two-factor authentication and an integrity check. All of it with no database and no plugins, in a 402 KB archive. Éclair is a fast CMS that packs everything a professional website needs into a 402 KB archive: speed, search rankings, visibility in AI answers, comfortable editing and security. There are no plugins to hunt down, install or update: everything is built in, preconfigured and documented. ## Éclair by the numbers ### 17 blocks in the editor, from FAQ to contact form ### 30 AI bots managed in one click in robots.txt ### 7 languages for the admin, 6 for the public site ### 299 automated checks in Éclair’s test suite ## What makes Éclair a fast CMS? A simple principle: a page that has already been generated is never rebuilt, which makes Éclair a fast CMS even on modest hosting. Éclair saves every public page to a static cache, then `index.php` serves it directly, **without loading the application or reading a single piece of content**. The cache clears itself whenever you change something, and at the scheduled time for a scheduled post. - **CSS inlined in the page** (about 12 KB minified for the default theme) and system fonts: no render-blocking requests, no layout shift. - **Images optimized on upload**: resized to 2000 px max, available as responsive WebP (480, 800, 1200 and 1600 px), with explicit dimensions and lazy loading. - **A single public script**, deferred: 1.2 KB compressed. - **ETag and 304 responses**, Brotli or Gzip compression and one-year browser caching for static files, through the included `.htaccess`. ### 100 out of 100 on Lighthouse for performance, accessibility, best practices and SEO ### 0.7 ms server response time for a cached page, measured locally ### 7 to 10 KB of compressed HTML per page, CSS included ### 1.2 KB of JavaScript on the public site > **How were these figures measured?** — On Éclair’s demo site, locally (PHP 8.3), with Lighthouse 12 on mobile and desktop. On real shared hosting, add network latency and your host’s PHP startup time: pages stay very fast, but a score can vary by one point from one run to the next. ## Which SEO tools are built in? Everything WordPress SEO plugins offer, with nothing to install. The details are in the [SEO documentation](https://eclaircms.org/en/documentation/seo). - **Real-time analysis** in the editor, with a score out of 100: title and meta description length, keyphrase (title, URL, introduction, subheadings, density), word count, structure, alt text, internal links, featured image. - **Live Google preview** and character counters for the title and description. - **JSON-LD structured data**: WebSite, Organization, Person or LocalBusiness, WebPage, AboutPage, ContactPage, BlogPosting, BreadcrumbList, FAQPage, ProfilePage. - **XML sitemap** with images and `hreflang`, robots.txt, a full RSS feed, Open Graph and Twitter Cards with a **1200 × 630 share image generated automatically**. - **Automatic 301 redirects** when a URL changes, plus a redirect manager to take over an old site. - **One URL per piece of content**: redirects for HTTPS, www or non-www, trailing slashes, uppercase and `index.php`. - **IndexNow**: Bing, Yandex, Seznam and other compatible engines are notified every time you publish. ## How does Éclair help you get cited by AI? GEO (*Generative Engine Optimization*) means making your site easy for ChatGPT, Perplexity, Gemini, Claude or Copilot to read and cite. Éclair automatically publishes what these engines know how to use. - **`/llms.txt` and `/llms-full.txt`**, following the [llmstxt.org](https://llmstxt.org/) proposal: your site’s map for AI. - **A Markdown version of every page**: add `.md` to any URL (it stays out of Google thanks to `noindex` and the canonical URL). - **A one-click AI bot policy**: open, citations only (answer engines allowed, training refused) or closed. - **The “Key takeaways” block** at the top of each article, the summary AI likes to quote. - **A GEO score**: FAQ, question-style subheadings, concrete figures, sources, identified author, short paragraphs, freshness. ![Éclair’s AI & GEO settings: choosing the access policy for artificial intelligence bots](https://eclaircms.org/media/2026/10/en-ai-geo-settings.webp) *Settings › AI & GEO: allow, limit or block AI bots in one click.* To dig deeper: [the GEO documentation](https://eclaircms.org/en/documentation/geo) and our guide to [getting cited by ChatGPT](https://eclaircms.org/blog/geo-get-cited-by-chatgpt). ## What is the editor like? It’s a block editor designed to help you write quickly and well: type **`/`** on an empty line to choose from the 17 blocks (text, subheading, list, quote, image, callout, FAQ, table, button, video, code, separator, banner, features, team, latest posts, contact form). - **Assisted internal links**: as you type a link, the editor suggests your pages and posts. - **Smart paste** from Word, Google Docs or a web page: headings, lists, tables and bold text become clean blocks. - **Nothing gets lost**: `Ctrl+S` to save, a local backup draft if the connection drops, and a history of the last 20 versions. - **Real preview** before publishing and **scheduled publishing** in your site’s time zone. - **Cookie-free YouTube and Vimeo videos** until the visitor clicks. All the details, shortcuts included: [the block editor](https://eclaircms.org/en/documentation/editor). ## What does the AI assistant do? It writes drafts, improves your texts and creates images **in your site’s voice**, with Claude (Anthropic) or ChatGPT (OpenAI) and your own API key. There’s no subscription: you pay the provider for what you actually use, about $0.24 per full post with Claude Opus 5.5. The assistant prepares, and only you publish: it can’t publish, delete or touch the settings. ![The AI assistant prepares to add a person and her photo to the About page, with Preview, Apply and Dismiss buttons](https://eclaircms.org/media/2026/10/en-ai-assistant-proposal.webp) *On a published page, the assistant suggests; nothing changes until you approve.* 5-minute setup and detailed costs: [the AI assistant](https://eclaircms.org/en/documentation/ai-assistant). ## Which protections are on by default? All of them, with nothing to configure. Éclair went through an offensive security review: 17 vulnerabilities were found and all of them fixed, then the 13 attack scenarios were replayed against the fixed version. | Threat | Éclair’s protection | | --- | --- | | SQL injection | No database | | Password theft | Argon2id, two-factor authentication and recovery codes | | Brute force | Limits per network and per account, your usual device never locked out | | XSS vulnerability | Allowlist-based content sanitizing, strict Content-Security-Policy | | Booby-trapped file | Re-encoded images, SVGs refused, no executable scripts in `/media` | | File modified behind your back | Integrity check of every file | Full details: [Éclair’s security](https://eclaircms.org/en/documentation/security). ## What about the rest of the site? - **Media library**: drag and drop, alt text, detection of images in use. - **Drag-and-drop menus** for the header and footer. - **“Pillar” categories** to organize your blog as a topic cluster. - **Site search**, weighted (title, summary, text). - **Spam-proof contact form without a captcha**: honeypot field, token, 5 messages per network every 10 minutes and 100 per day for the whole site, with an inbox in the admin. - **Administrator and editor accounts.** - **Appearance**: main color with guaranteed WCAG contrast, eight system font styles, logo, icon and automatic dark mode. - **Multilingual**: admin in 7 languages (French, English, Spanish, German, Italian, Portuguese, Chinese), public site in 6 languages, with linked translations and `hreflang` tags. ![An article on an Éclair site, automatically displayed in dark mode](https://eclaircms.org/media/2026/10/mode-sombre.webp) *The site automatically follows each visitor’s light or dark theme.* ## What doesn’t Éclair do? Better to know before you choose. Éclair deliberately focuses on business websites, blogs, portfolios and sales pages. - **No online store**: no cart, no payments, no inventory management. - **No plugins**: a deliberate choice, for speed and security. The theme, on the other hand, can be customized. - **No member area** and no visitor registration. - **No automatic WordPress importer**: you migrate with smart paste and redirects, [step-by-step method here](https://eclaircms.org/blog/migrate-from-wordpress). If your project needs any of these, WordPress or a specialized tool will be a better fit: our [Éclair vs WordPress comparison](https://eclaircms.org/en/eclair-vs-wordpress) helps you decide. ## Questions about the features ### Do I need plugins for SEO or caching? No. Static caching, SEO, GEO, the sitemap, redirects, the contact form and backups are built into Éclair and active as soon as it’s installed. ### Does Éclair work without JavaScript for visitors? Yes. The public site uses just one 1.2 KB script, deferred, for the contact form, videos and the “Edit” button shown to logged-in users. Pages display fully without it. ### Can I build a multilingual site? Yes. Each piece of content has its own language (French, Spanish, English, German, Italian or Portuguese) and you link its translations together: Éclair adds the `hreflang` tags and a “Read in…” link to the page. ### Can I customize the design? Yes: color, fonts, logo and dark mode are set in Settings › Appearance, and developers can edit the theme (PHP templates and CSS). This very site, eclaircms.org, uses a custom theme. [Download Éclair for free](https://eclaircms.org/en/download)