# Outils SEO gratuits

> Tous les outils SEO gratuits : audits, robots IA, test robots.txt, sitemap, schema, redirections, vitesse, SSL et plus. Sans inscription ni limite.

## Audits SEO

- [Vérificateur SEO gratuit](https://yes-seo.com/fr/verificateur-seo-gratuit): Full single-page SEO audit with no signup: 0–100 SEO score plus an AI-visibility score, 60+ checks, prioritized fix list with why/how, SERP and social previews, keywords, headings, AI crawler access, tech stack, export to Markdown/JSON/print. 10 free audits a day.
- [Audit SEO de site web](https://yes-seo.com/fr/audit-seo-site-web): Website SEO audit: free single-page audit, or a whole-site crawl (up to 100 pages on Pro, 250 on Agency) that finds broken internal links, duplicate titles/descriptions, thin pages and site-wide issues, ranked by impact.
- [Analyse SEO](https://yes-seo.com/fr/analyse-seo): SEO analyzer that reads a page like Googlebot (server HTML, no JS): titles, headings, canonical, robots, hreflang, schema, links, speed signals, security headers, with a plain-English fix for every issue.
- [Score SEO d’un site](https://yes-seo.com/fr/score-seo-site): Check a website SEO score from 0 to 100 and see exactly which checks cost points, the category breakdown (indexing, content, links, speed, mobile, security, social) and which fixes raise the score most.
- [Vérificateur SEO on-page](https://yes-seo.com/fr/verificateur-seo-on-page): On-page SEO checker: title, meta description, H1 and heading outline, content depth, keyword consistency between title/H1/description, image alt text, internal links, readability.
- [Générateur de rapport SEO](https://yes-seo.com/fr/generateur-rapport-seo): SEO report generator: shareable report link, free Markdown/JSON export and print-to-PDF; white-label branded PDF reports (logo, colors) on Pro and Agency plans for client work.
- [Vérificateur SEO IA](https://yes-seo.com/fr/verificateur-seo-ia): AI SEO / GEO checker: AI-visibility score (0–100) showing whether ChatGPT, Claude, Perplexity, Gemini and Google AI Overviews can access, understand and cite a page: AI crawler access in robots.txt, server-rendered text, snippet directives, answer-ready structure, entity schema, author/date (E-E-A-T) signals, freshness, citations, llms.txt (optional).
- [Comparateur SEO](https://yes-seo.com/fr/comparateur-seo): Compare the SEO of two pages side by side (yours vs a competitor): scores, title and description, word count, headings, links, schema, speed, AI readiness, with the gaps highlighted.

## Recherche IA (GEO)

- [Vérificateur de robots IA](https://yes-seo.com/fr/verificateur-robots-ia): AI crawler checker: tests a site's robots.txt against 25+ AI bots (GPTBot, OAI-SearchBot, ChatGPT-User, ClaudeBot, Claude-SearchBot, Claude-User, PerplexityBot, Perplexity-User, Google-Extended, Applebot-Extended, CCBot, Meta-ExternalAgent, Bytespider, Amazonbot, DuckAssistBot, MistralAI-User and more), grouped by purpose (search, user fetch, training), plus a live firewall test that requests the page with real AI user-agents to detect 403 blocks.
- [Générateur llms.txt](https://yes-seo.com/fr/generateur-llms-txt): llms.txt generator and validator: checks whether /llms.txt exists and is well-formed (H1, summary, link sections), and generates a ready-to-upload llms.txt draft from the site's home page, navigation and sitemap. Honest note: llms.txt is optional and no major AI platform has confirmed using it for ranking or citations.

## On-page et contenu

- [Vérificateur balises meta](https://yes-seo.com/fr/verificateur-balises-meta): Meta tags checker: lists every meta tag of a page (title, description, robots, viewport, charset, canonical, Open Graph, Twitter, hreflang, verification tags) with length and pixel-width checks and fixes.
- [Aperçu SERP](https://yes-seo.com/fr/simulateur-serp): SERP snippet preview / Google simulator: type or fetch a title, meta description and URL and see the desktop and mobile Google result with real pixel-width truncation (title ~580 px, description ~920 px), character counts and a live checklist.
- [Vérificateur de balises Hn](https://yes-seo.com/fr/verificateur-titres-hn): Heading checker: shows the H1–H6 outline of a page as a tree, flags missing or multiple H1, skipped levels, empty and overlong headings.
- [Densité de mots-clés](https://yes-seo.com/fr/densite-mots-cles): Keyword density checker: top 1-, 2- and 3-word phrases with counts and density for a URL or pasted text (stop words removed in English, French, Spanish and Arabic), and whether the main phrases appear in the title, H1 and description.
- [Vérificateur alt d’images](https://yes-seo.com/fr/verificateur-alt-images): Image alt text and image SEO checker: every image on a page with its alt text, file size, format (JPEG/PNG vs WebP/AVIF), dimensions, lazy loading; flags missing alt, oversized files and layout-shift risks.
- [Analyseur de liens](https://yes-seo.com/fr/analyseur-liens): Link analyzer: every internal and external link on a page with anchor text, rel attributes (nofollow, sponsored, ugc), empty anchors, duplicates and counts.
- [Compteur de mots](https://yes-seo.com/fr/compteur-de-mots): Word and character counter: words, characters with and without spaces, sentences, paragraphs, reading and speaking time, keyword frequency; works in any language, entirely in the browser.
- [Test de lisibilité](https://yes-seo.com/fr/test-lisibilite): Readability checker: Flesch Reading Ease (English), Kandel-Moles (French), Fernández Huerta (Spanish), plus sentence length, long sentences, word length and passive-voice hints for a URL or pasted text.
- [Vérificateur Open Graph](https://yes-seo.com/fr/verificateur-open-graph): Open Graph and Twitter Card checker: previews how a link looks when shared on Facebook, X/Twitter, LinkedIn, WhatsApp and Slack, validates og:image size and every tag.
- [Générateur de balises meta](https://yes-seo.com/fr/generateur-balises-meta): Meta tag generator: fill a form and copy ready HTML for title, description, robots, canonical, viewport, Open Graph, Twitter Card and hreflang tags, with a live SERP preview.

## SEO technique

- [Testeur robots.txt](https://yes-seo.com/fr/testeur-robots-txt): robots.txt tester: fetches and parses robots.txt, tests any URL against Googlebot, Bingbot and AI bots with Google's longest-match rules, highlights the matching rule, syntax errors and sitemap lines. Also accepts pasted robots.txt rules.
- [Générateur robots.txt](https://yes-seo.com/fr/generateur-robots-txt): robots.txt generator: build a robots.txt with presets (allow all, block admin areas, block or allow AI training bots, allow AI search bots), custom rules and sitemap lines.
- [Validateur de sitemap XML](https://yes-seo.com/fr/validateur-sitemap): XML sitemap validator: finds the sitemap (robots.txt, /sitemap.xml, sitemap index), validates XML and limits (50,000 URLs / 50 MB), lastmod dates, hreflang alternates, and status-checks a sample of listed URLs for 404s, redirects and noindex.
- [Générateur de sitemap XML](https://yes-seo.com/fr/generateur-sitemap): XML sitemap generator: crawls up to 300 pages of a site (respecting robots.txt, skipping noindex and non-canonical pages) and produces a downloadable sitemap.xml.
- [Vérificateur de redirection](https://yes-seo.com/fr/verificateur-redirection): Redirect checker: traces every hop of a redirect chain (301, 302, 307, 308, meta refresh) with status, location, timing; detects loops, long chains and http→https / www consolidation.
- [Vérificateur d’en-têtes HTTP](https://yes-seo.com/fr/verificateur-en-tetes-http): HTTP header checker: shows the raw response headers (status, server, cache-control, content-type, encoding, X-Robots-Tag, link, HSTS) and explains the SEO-relevant ones.
- [Vérificateur de code HTTP](https://yes-seo.com/fr/verificateur-code-http): Bulk HTTP status code checker: paste up to 50 URLs and get each status code, redirect target and response time.
- [Vérificateur de liens cassés](https://yes-seo.com/fr/verificateur-liens-casses): Broken link checker: tests up to 200 links on a page (internal and external) for 404, 410, 5xx, DNS errors and redirects, with the anchor text of each broken link.
- [Vérificateur canonical](https://yes-seo.com/fr/verificateur-canonical): Canonical checker: finds rel=canonical in HTML and HTTP headers, checks it is absolute, self-referencing or intentional, returns 200 and is indexable, and tests http/https and www/non-www variants redirect to one version.
- [Vérificateur hreflang](https://yes-seo.com/fr/verificateur-hreflang): Hreflang checker: lists hreflang alternates from HTML, HTTP headers, validates language/region codes, x-default, self-reference, and fetches each alternate to verify return links and canonicals.
- [Validateur de schema](https://yes-seo.com/fr/validateur-schema): Schema markup validator: extracts JSON-LD, microdata and RDFa types, validates JSON syntax and Google's required/recommended properties for Article, Product, Organization, LocalBusiness, BreadcrumbList, Event, Recipe, VideoObject, JobPosting, Review, SoftwareApplication; notes that FAQ (since 2026) and HowTo rich results are no longer shown by Google.
- [Générateur de schema](https://yes-seo.com/fr/generateur-schema): Schema markup generator: build JSON-LD for Organization, LocalBusiness, Article, Product, BreadcrumbList, Person, Event, WebSite, SoftwareApplication and FAQPage with a form, then copy the script tag.
- [Test de vitesse de site](https://yes-seo.com/fr/test-vitesse-site): Page speed test: server response time (TTFB), download time, HTML size and compression, HTTP version, number and weight of scripts, styles and images, render-blocking resources, caching and modern image formats; Core Web Vitals (LCP, INP, CLS) from Google PageSpeed Insights when available.
- [Test de compatibilité mobile](https://yes-seo.com/fr/test-compatibilite-mobile): Mobile-friendly test: viewport tag, responsive CSS (media queries), fixed-width elements, legible base font, tap-target hints, responsive images, plugins, interstitial hints — static checks since Google retired its own Mobile-Friendly Test in 2023.
- [Vérificateur d’indexabilité](https://yes-seo.com/fr/verificateur-indexabilite): Indexability checker: answers "can Google index this page?" in one view: HTTP status, robots.txt rule, meta robots and X-Robots-Tag, canonical target, sitemap presence, redirect, nosnippet — with the blocking reason highlighted.
- [Détecteur de CMS](https://yes-seo.com/fr/detecteur-cms): Website technology checker / CMS detector: detects the CMS (WordPress, Shopify, Wix, Squarespace, Webflow, Joomla, Drupal, Magento, Ghost…), frameworks (Next.js, Nuxt, React, Vue, Angular), CDNs, analytics and tag managers, servers and SEO plugins from HTML and headers.
- [Soumission IndexNow](https://yes-seo.com/fr/soumission-indexnow): IndexNow submitter: generate an IndexNow key, verify the key file on your site and submit up to 1,000 URLs to Bing, Yandex, Naver, Seznam and Yep in one click (Google does not support IndexNow).

## Domaine et sécurité

- [Vérificateur SSL](https://yes-seo.com/fr/verificateur-ssl): SSL certificate checker: issuer, validity dates and days left, covered domains (SAN), key and signature, TLS version, and whether HTTP redirects to HTTPS.
- [En-têtes de sécurité](https://yes-seo.com/fr/verificateur-en-tetes-securite): Security headers checker: grades A+ to F for Strict-Transport-Security, Content-Security-Policy, X-Content-Type-Options, X-Frame-Options, Referrer-Policy, Permissions-Policy and cookie flags, with copy-paste fixes for Apache, Nginx and Cloudflare.
- [Recherche DNS](https://yes-seo.com/fr/recherche-dns): DNS lookup: A, AAAA, CNAME, MX, NS, TXT, SOA and CAA records, with SPF and DMARC parsed and checked for common mistakes.
- [Âge du nom de domaine](https://yes-seo.com/fr/age-du-domaine): Domain age and expiry checker (RDAP/WHOIS): registration date and age, expiry date and days left, registrar, status codes and name servers.