Free SEO tools
Paste a public URL, read what the checker found, and what it cannot prove. No signup.
Crawling & indexing
Check crawler access and other indexability signals on a public URL.
Canonical Tag Checker
Free, no account. A canonical tag can look perfect in view-source and still be doing nothing — because a header contradicts it, because its target redirects, or because the www version of the same page says something different. This checks the declaration in both places it can live, follows the target to confirm it's usable, and compares the URL variants that usually turn out to be the actual problem.
Open toolrobots.txt Generator
Free, no account. Pick which crawlers you want to keep out — AI training bots without touching search, or particular paths without touching everything — then test real URLs against the rules before the file goes anywhere near your server. Nothing you enter leaves this page.
Open toolrobots.txt Tester
Free, no account. A misplaced Disallow doesn't announce itself — it just quietly stops half a site being crawled, and you find out weeks later. Paste a robots.txt and a list of URLs, pick your crawlers, and get a verdict for every combination with the exact line that decided it. Nothing you paste leaves this page.
Open toolDomain & site health
Read the transport, policy and disclosure signals a public URL exposes to any visitor.
HTTP Header Checker
Free, no account. Before a browser renders anything, the server sends a set of headers deciding whether the page can be cached, framed, indexed or trusted — and a redirect chain can quietly change all of it on the way. Check any public URL and see every hop, every header, and what each one means, graded separately for security and for search.
Open toolPre-publish Comparison
Free, no account. A line-by-line diff of two HTML documents buries five real changes under four thousand irrelevant ones. Paste your draft and your current live page and see only the signals a search engine reads — title, canonical, robots, hreflang, headings, structured data — with anything removed flagged before you approve the release. Nothing you paste leaves this page.
Open toolWebsite Security Checker
Free, no account. A graded snapshot of what a page exposes publicly — whether every hop stays on HTTPS, whether anything loads over plain HTTP, whether your forms and cookies are protected, and whether your Content-Security-Policy does anything at all. It is a passive check on public responses, not a penetration test, and the difference is explained below.
Open toolInternational SEO
hreflang Tester
Free, no account. An hreflang set only works when every page in it points at every other page, including itself — so checking one page's tags tells you almost nothing. Enter a URL and this fetches every alternate it declares, confirms they point back, and checks each one is actually a valid destination: right status, right canonical, indexable.
Open toolJavaScript & rendering
Compare the HTML the server returns with what appears after JavaScript runs.
Raw vs. Rendered HTML Checker
Free, no account. A page can look complete in a browser while a crawler still reads the raw HTML first. Paste a public URL to see where the two diverge, and whether a render even ran.
Open toolOn-page
Inspect titles, headings, canonicals, robots, links, and images in the raw HTML.
Free SEO Page Audit
Enter any page of your website and get an instant health check with the key issues holding it back in Google.
Open toolInternal Link Checker
Free, no account. Most link tools hand you a thousand rows, and nine hundred of them are your navigation counted once per menu. This one separates the template from the content, so you can see the internal links this page actually makes — their anchor text, whether they're crawlable at all, and where the same words point to different places. Enter a public URL.
Open toolMobile vs Desktop Parity Checker
Free, no account. Google indexes the mobile version of your page — so anything that exists only on desktop effectively doesn't exist. Nothing warns you about it, because nothing looks broken. Enter a URL and see exactly what your mobile response is missing: content, internal links, structured data, and the directives that decide whether the page is indexed at all.
Open toolOn-Page SEO Checker
Free, no account. Paste a public URL for a five-item on-page memo from the raw HTML, then open Advanced for the full detector output. This is not a ranking score, and it does not execute JavaScript.
Open toolSemantic Content Map
Free, no account. Upload a crawl export and see how your content actually relates: which pages overlap enough to be competing with each other, which pairs are closely related and don't link, and which pages sit on their own with nothing near them. It's a map for making editorial decisions — not a score, and not a list of things to delete.
Open toolPerformance & Core Web Vitals
Core Web Vitals Checker
Free, no account. Two different things get called Core Web Vitals, and only one of them counts for search: what real Chrome users measured on your page over the past month. This shows that first, on its own, then runs a lab audit to explain what's behind it — and tells you plainly when there isn't enough real-user data to report.
Open toolFree SEO Page Audit
Enter any page of your website and get an instant health check with the key issues holding it back in Google.
Open toolSERP & snippets
Write and measure titles and descriptions the way they appear on a results page.
Favicon Checker
Free, no account. Checks every icon your site declares — plus the ones browsers look for whether you declare them or not — and fetches each one to confirm it actually exists at the right size. Also checks the thing that usually explains a missing favicon in search results, which is that a crawler can't reach the file at all.
Open toolGoogle SERP Simulator
Free, no account. Type a title and description and see how they'd render in search, measured in pixels rather than characters, for desktop and mobile at once — with query-matched bolding counted in the width, because that's what actually pushes a title past the edge. Nothing you type leaves this page.
Open toolH1 Generator & Checker
Free, no account. Plenty of sites don't have the H1 they think they have — a lot of themes wrap the site logo in one, so every page's main heading is the brand name. Enter a URL to see what your H1 actually is, how it relates to your title and your content, and get better options written from the page itself.
Open toolMeta Description Generator
Free, no account. Descriptions get rewritten by Google more often than not — which is a reason to write a good one, not a reason to skip it. This reads your page and drafts descriptions from what's actually there, measured to fit, with nothing invented that the page doesn't say.
Open toolMeta Title Generator
Free, no account. Most title generators take a keyword and hand back five versions of the same sentence. This one reads your actual page — the heading, the content, what's already there — and writes options from that, each measured in pixels so it fits, with nothing invented that isn't on the page.
Open toolOpen Graph & Social Preview
Free, no account. Most preview tools read your tags and draw a card. This one fetches the image too — because a preview that looks perfect in a mock-up and breaks when shared is almost always an image problem, not a tag problem. Check what each platform will actually display, and find out why the old version is still showing.
Open toolStructured data & entities
Build JSON-LD in the browser and check it against current search-engine requirements.
Schema Markup Generator
Free, no account. Choose what your page is about, fill in a short form, and copy out structured data that actually describes it — checked as you type against the requirements search engines publish today, including the ones they've quietly stopped supporting. Everything happens in this browser; nothing you enter is sent anywhere.
Open toolWhat these tools do
Each checker reports what it observed on a public URL or in page HTML. That is not a ranking score, and a pass is not proof that a search engine indexed or rendered the page the same way.
No signup. Submitted URLs and results are not stored. Live checks go through the site API with private-network blocks, a 2 MB / 10s cap, and a per-IP rate limit. Some tools run entirely in the browser.
Every tool page states what it cannot prove. Use Search Console (or equivalent) when you need index status.