Free SEO audit: what it sees, what it misses, and what to fix first

What a free audit can see, and what it cannot

On Google France, “audit seo gratuit” (free SEO audit) is searched 880 times a month and “analyse seo gratuite” (free SEO analysis) 480 times. Behind these searches sits the same expectation: to find out in a few minutes why the website brings in no customers. A free tool answers part of that question, and it pays to know which part.

It sees everything that is public in your page and your technical files: title, description, headings, text, images, structured data, links, contact buttons, robots.txt, sitemap and llms.txt. These are verifiable facts that anyone can check on screen.

It cannot see what only Google knows: which pages are actually indexed, which searches you appear for and in what position, how many clicks you receive. That data lives in your Google Search Console. Nor can it see, without a paid tool, the links from other sites to yours or how competitive your trade is in your city.

A good free audit is therefore for clearing the obvious blockers and setting priorities. A complete strategy then calls for Google Search Console and a study of what your customers actually search for.

Pillar 1: found on Google (11 checks)

These checks make sure Google can get in, read and understand your home page. Three of them are critical: if they fail, the rest hardly matters.

• Site served over HTTPS (critical): without a secure address, browsers display a warning. Passed by 96% of the sites in our study.
• Google can crawl the site (critical): robots.txt must not shut Googlebot out. Passed by 99% of the sites in our study.
• Mobile-friendly (critical): the viewport tag announces a mobile layout, the one Google crawls first. Passed by 95% of the sites in our study.
• A page title of 25 to 65 characters, with your trade and city or your offer. Passed by 59% of the sites in our study.
• A single H1 that says what you sell, not just your name. Passed by 55% of the sites in our study.
• At least 400 useful words on the home page, menus excluded. Passed by 60% of the sites in our study.
• A sitemap published or declared in robots.txt. Passed by 82% of the sites in our study.
• Described images: at least 80% with alt text. Passed by 79% of the sites in our study.
• A meta description of 70 to 165 characters, the text that makes people want to click. Passed by 50% of the sites in our study.
• A fast server response: under 1.5 seconds for the home page.
• A declared canonical URL, so Google does not hesitate between several versions of a page. Passed by 79% of the sites in our study.

Pillar 2: cited by AI (6 checks)

ChatGPT, Perplexity, Copilot and Google’s AI answers cite pages they can read and whose facts they understand. These checks make sure you are not closing the door and that your information is easy to reuse.

• AI assistants allowed (critical): robots.txt does not block OAI-SearchBot, GPTBot, PerplexityBot, Claude-SearchBot, ClaudeBot, Bingbot or Google-Extended. Passed by 98% of the sites in our study.
• The business described in structured data (name, activity, address, opening hours, phone). Passed by 45% of the sites in our study.
• Frequently asked questions on the page, with real answers. Passed by 19% of the sites in our study.
• An llms.txt file that sums up the offer for assistants. Passed by 20% of the sites in our study.
• The page language declared. Passed by 94% of the sites in our study.
• A sharing preview (Open Graph) for social networks and messaging apps. Passed by 72% of the sites in our study.

Pillar 3: turns visitors into customers (3 checks)

Being found is not enough: visitors must be able to contact you in a single tap, especially on a phone.

• A tappable phone number or WhatsApp link on the home page. Passed by 61% of the sites in our study.
• A short enquiry form on the home page. Passed by 52% of the sites in our study.
• At least 10 internal links from the home page to the pages that sell. Passed by 74% of the sites in our study.

When it detects an online shop, the tool adjusts the weight of some checks and, on Shopify sites, adds two checks on the public catalogue: a single product page per product and described category pages.

How to read your score

Each check is worth a number of points according to its weight, and each pillar has its own score out of 100. The overall score is the share of points earned, with one rule: a single failed critical check caps the score at 59. A site closed to Google cannot show a good score, even if it passes everything else.

For reference: half of the sites in our study score between 59 and 82, and 27% are below 60. The weakest pillar in the study is “turns visitors into customers”, with a median of 64 out of 100.

What to fix first

The tool ranks fixes by severity, then by weight. Follow that order: it matches the real impact.

1. 1
   The critical issues: HTTPS, robots.txt, mobile layout, AI assistants allowed. They can often be fixed in an hour and unlock everything else.
2. 2
   The page title and the H1: your trade and your city, stated clearly. For most small businesses, this is the fix that pays off most.
3. 3
   One-tap contact and the form: every visitor you win must be able to call.
4. 4
   Home page content and one page per service: answer the questions your customers ask before they call.
5. 5
   Structured data, the FAQ and llms.txt: make your facts readable by Google and AI.