Free tools you can run on your own website

A word on scores before you start. These tools produce numbers, and the numbers are easy to chase for their own sake. A site scoring 78 that loads in under two seconds and converts visitors is worth more than a site scoring 100 that says nothing convincing. Treat every result as a list of questions to ask rather than a grade.

Speed and page experience

PageSpeed Insights — pagespeed.web.dev. Paste a URL and it reports on both mobile and desktop. The section worth your attention is the one at the top, drawn from real Chrome users who visited your site over the past month. The lab scores underneath are a simulation on a throttled connection, which is why the mobile number often looks alarming.

Three measurements carry most of the weight. LCP is how long the biggest thing on screen takes to appear, usually a hero image. CLS is how much the page jumps around while loading, which is what happens when images have no dimensions reserved for them. INP is how quickly the page responds when someone taps something.

Lighthouse — built into Chrome. Right-click any page, choose Inspect, and find the Lighthouse tab. It runs the same audit as PageSpeed Insights with one advantage: it works on a site that is still private, so you can test before anything is live.

How search engines see the site

Google Search Console — search.google.com/search-console. The most valuable free tool a website owner has, and the one most often left unopened. It requires verifying that you own the domain, usually through a DNS record. It will show you which searches actually brought people to your site, which pages Google has indexed and which it has skipped and why, and any structured data it has found.

The URL Inspection tool inside it answers a question people otherwise guess at: has Google seen this specific page, and what did it make of it?

Bing Webmaster Tools — bing.com/webmasters. Same idea, second search engine, ten minutes to set up. Worth having because Bing feeds several AI assistants, so its view of your site reaches further than its search share suggests.

Structured data

Structured data is machine-readable information about your business sitting invisibly in the page: who you are, what you sell, where you work, what your articles are about. It is how a search engine or an AI assistant tells your phone number apart from any other number on the page.

Rich Results Test — search.google.com/test/rich-results. Google's own validator. Paste a URL and it reports what it found and whether the markup is eligible for any enhanced display.

Schema Markup Validator — validator.schema.org. Broader than Google's test, since it checks the markup against the schema.org vocabulary rather than against Google's specific requirements. Use it when you want to know whether your markup is correct in general.

Accessibility

WAVE — wave.webaim.org. Overlays icons directly on your page showing missing image descriptions, contrast failures, empty links, and heading problems. The visual output makes it far easier to act on than a list of error codes.

Lighthouse accessibility score — same tab as the speed audit. Useful, and worth knowing its limits: automated testing catches somewhere around a third of accessibility problems. A perfect score means the machine-checkable things are right.

Your keyboard — free, already installed. Put your mouse down and press Tab repeatedly through a page. You should always be able to see where you are, reach every link and button, open and close every menu, and fill in every form. If focus disappears somewhere invisible, or a menu opens that you cannot close, you have found something worth fixing.

Code and links

Nu HTML Checker — validator.w3.org/nu. The W3C's validator. Browsers are forgiving of broken markup, which means errors accumulate silently and then surface as strange behavior in one browser or one screen reader.

Screaming Frog SEO Spider — screamingfrog.co.uk. A desktop application, free for up to 500 URLs, which covers most small business sites entirely. It crawls the whole site the way a search engine would and hands you a spreadsheet: broken links, redirect chains, missing or duplicated titles and descriptions, images with no alt text, pages nothing links to.

Security and certificates

SSL Labs Server Test — ssllabs.com/ssltest. Grades how your certificate and encryption are configured. Takes a couple of minutes to run and is worth doing once after any hosting change.

Security Headers — securityheaders.com. Checks whether your site sends the HTTP headers that limit what a browser will do on your behalf. Most small business sites score an F here and nobody has ever mentioned it to them.

Social and link previews

These decide what appears when someone pastes your link into a message, a post, or an email. Getting it wrong is the difference between a link that looks like a professional business and a link that looks like nothing.

Facebook Sharing Debugger — developers.facebook.com/tools/debug, and LinkedIn Post Inspector — linkedin.com/post-inspector. Both show you the preview as their platform sees it. Both also cache aggressively, so if you have fixed an image and the old one still appears, these are the tools that force a fresh look.

What none of these will tell you

Every tool here measures something a machine can measure. None of them can tell you whether your writing answers the question a visitor arrived with, whether your prices make sense to the person reading them, or whether someone finishes your homepage understanding what you do. A site can pass every test on this page and still fail the only test that matters.

Run them anyway. They catch real problems, and a clean result rules out a whole category of explanation when something is going wrong.