The free tools on this site handle the specific, mechanical checks that used to mean opening a paid platform for a two-minute job. Each one does one thing: checks your title tags, tests your robots.txt file, previews how a page looks in the SERP (Search Engine Results Page), or traces a redirect chain. You paste a URL, get an answer, and move on.
What each tool actually checks
These are not cut-down demos of a bigger product. They are built to answer one question properly.
- The Title Tag Scorer takes a title tag and an optional target keyword, then scores the title out of 100 against a set of checks: character length (50 to 60 is the target range), pixel width measured against Google's roughly 600px desktop limit, whether the keyword appears and how early, duplicate words, keyword stuffing, all-caps, a trailing brand separator, and generic openers. The score comes with a one-sentence breakdown for each signal, alongside a desktop SERP-style preview that truncates exactly where Google would, and both update as you type. It runs entirely in the browser, with no server, API key, or third-party proxy involved, and states what it cannot see.
- The Meta Tag Checker takes the HTML source of a page, pasted into a text box straight from View Source, and parses out the title tag, meta description, canonical URL, robots directives, viewport tag, Open Graph and Twitter card tags, hreflang links, and the first H1, each shown with its length and a pass, warn, or fail check for the usual problems: missing or empty values, a title or description running too long, duplicate tags, a stray noindex, or a canonical pointing somewhere else entirely. It builds a Google-style snippet preview from the title and description as you go. There's also a URL field that attempts a direct fetch, though most sites block that kind of cross-origin read, so the interface says as much and points you back to pasting the source in instead. It runs entirely in the browser, with no server, API key, or third-party proxy involved, and states what it cannot see.
- The Robots.txt Tester takes the contents of a robots.txt file pasted into a text box, a URL path, and a choice of user-agent (Googlebot, Googlebot-Image, Bingbot, or a generic *), then works through the file per the robots exclusion protocol, user-agent groups, Allow and Disallow rules, longest-match wins, wildcards, and Sitemap lines, to report whether that path is allowed or disallowed for that agent, quoting the exact line that decided it. It also flags syntax slips such as an unknown directive, a missing user-agent group, or conflicting rules of equal length, and lists any Sitemap URLs it finds. There's an optional button that tries to fetch the file straight from a domain, though most sites block that kind of cross-origin read, so pasting the file in directly is the more reliable route. It runs entirely in the browser, with no server, API key, or third-party proxy involved, and states in the interface what it cannot see. Worth confirming after any site migration.
- The Redirect Chain Checker works from what you can see, because a browser cannot observe another site's redirect hops on its own. Paste the chain as one hop per line in the form "<status> <url>" (301 http://example.com/old, then 302 https://example.com/new, then 200 https://www.example.com/final), or paste the raw response headers from a curl -I run, and it parses the hop count, the final destination, whether the chain loops back on itself, http-to-https and www hops that could be collapsed into one, a temporary (302 or 307) hop sitting where a permanent (301 or 308) one belongs, and any method-changing 302. It shows the chain as a vertical timeline with a status badge on each hop, flags anything longer than two hops as too long for crawlers, and gives a plain verdict with the single-hop redirect it recommends instead. There's also a URL field that runs a best-effort fetch and, where the target allows a cross-origin read, reports whether the final response was redirected and where it landed; where the target blocks it, the tool says so and prints a curl -I -L command to run instead. Every extra hop spends crawl budget and dilutes the link equity passed through to the final page, which is why the chain length is worth knowing. It runs entirely in the browser, with no server, API key, or third-party proxy involved, and states what it cannot see.
- The Canonical URL Checker fetches a page's declared canonical tag and flags the common problems worth knowing about: a missing canonical, one that isn't self-referential when it should be, or one pointing to a URL that redirects. It sits naturally alongside the redirect chain checker, since those two problems often turn up together.
- The SERP Snippet Previewer takes a title, meta description, and URL, and renders a realistic Google result preview for desktop and mobile side by side. It measures pixel widths on a canvas, roughly 600px for a desktop title and 920px for a two-line mobile title, with the description held to around 920px across two lines, and truncates with an ellipsis exactly where the limit falls. Live character and pixel counts sit next to the preview in green, amber, or red bands, with a one-line tip the moment a title or description is about to get cut, and the URL renders as a breadcrumb the way Google shows it. It runs entirely in the browser, with no server, API key, or third-party proxy involved, and states what it cannot see.
- The Core Web Vitals Checker takes a URL and a mobile or desktop toggle, and calls Google's public PageSpeed Insights v5 endpoint to read back the loadingExperience field data: Largest Contentful Paint (LCP), Interaction to Next Paint (INP), and Cumulative Layout Shift (CLS), each at the 75th percentile. Each metric shows as a card with its value, Google's own thresholds (LCP at 2.5 seconds and 4 seconds, INP at 200ms and 500ms, CLS at 0.1 and 0.25), a pass, needs-improvement, or fail verdict, and the distribution bar behind it. Where no field data exists for the exact URL, it says so, and offers the origin-level result instead. Rate limits and failed calls come back as a plain, readable message. It runs entirely in the browser, with no server, API key, or third-party proxy involved, and states what it cannot see.
- The Keyword Difficulty Estimator takes a keyword phrase and a market selector (UK, US, or generic), then works out a difficulty band, Easy, Medium, Hard, or Very hard, from on-device heuristics: word count and specificity (whether the phrase is long-tail or a head term), commercial modifiers such as best, buy, price, or near me, brand names, question forms, and year or location qualifiers, alongside the SERP features those patterns tend to attract. It classifies the likely search intent, informational, navigational, commercial, or transactional, with one sentence explaining why, and suggests five to eight related long-tail variants built from the phrase you entered. The result is a heuristic estimate, and the tool says so, along with what's worth checking by hand before you commit to a keyword. It runs entirely in the browser, with no server, API key, or third-party proxy involved, and states what it cannot see.
Changing a title tag or meta description on the strength of the previewer is a reasonable move, but knowing whether the new version actually pulled in more clicks, or whether a page redesign lifted conversion rate, is a different question. The A/B Test Significance Calculator runs a Z-score test on the two sets of numbers and gives you a 95% confidence interval, which is a reasonable way to check whether the difference you're seeing is real or just noise, particularly on marketing, ecommerce, or analytics-driven pages where a few percentage points get argued over.
If the question runs the other way, and you're trying to work out whether a paid media quote is reasonable before you commit budget to it, that's a different tool for a different job. The CPM / CPC Benchmark Comparator lets you pick an advertising channel, whether that's Google Search, Meta, LinkedIn, TikTok, programmatic display, or YouTube, along with your industry vertical, and returns indicative UK CPM and CPC ranges alongside a note on what tends to drive the variance between them. It's a reasonable way to sense-check a quote from an agency or platform rep, or to see how one channel's costs compare with another before you shift spend around.
If you need to build a robots.txt file, the Robots.txt Generator walks you through which bots to block, which directories to disallow, and where your sitemap sits, then outputs a file ready to upload. Use our robots.txt tester to see how the rules you've written actually apply to a given path and agent before you upload anything: test what you have with the tester, build what you need with the generator, and between them they cover the file from creation through to confirmation.
Building rather than checking
Structured data (schema markup) is a similar case: you're building something. The SEO Schema Generator puts together JSON-LD for Article, Product, and FAQ page markup across three tabs, with the preview updating on every keystroke and a copy button that copies the exact schema generated, not a version with the word "copy" stripped out of it if that word happens to appear in your text. Any field you leave blank shows up as a clearly marked placeholder in the preview, with a notice next to the output telling you precisely which fields are still placeholders, so nothing invented gets mistaken for real data and pushed live by accident. It's a reasonable tool to run a schema draft through before pasting it into a page, since a price that won't parse or a half-finished FAQ pair is the kind of thing that's easy to miss by eye.
The meta tags that control how a page shows up when someone shares it are the same kind of job. The Social Card Generator (Open Graph) takes a title, description, image URL, and page URL, and builds a live preview of the sharing card alongside the block of meta tags that would produce it. Every value you type is escaped before it lands in an attribute, so a quote mark or an ampersand in a title can't break the tag, and the Open Graph and Twitter card tags are written with the attribute each specification actually reads. Leave a field empty and it's left out of the generated code entirely, type a bare domain into the URL field and the tool visibly adds the scheme, and a broken image URL gets a placeholder and a note. Worth running before a page goes live, since a malformed share card is the kind of thing you only notice once someone's already posted the link.
Any of these can return a wrong or incomplete answer, particularly on pages that rely heavily on JavaScript to render content, so treat the result as a starting point for investigation rather than a final verdict. If you're weighing up which keywords to chase before you write a word of copy, use the keyword difficulty estimator to see how this applies to your situation, and treat the band it gives you as a starting steer.
Where a free check stops being enough
A single-page check is useful for a specific question about a specific page. It is not a substitute for crawling a whole site, tracking rankings over weeks, or analysing a backlink profile, which is where the paid platforms earn their monthly fee. If you are past the point of spot-checking and into ongoing monitoring, the Rank Trackers Compared and Technical SEO Crawlers Compared pages set out what the paid options cover and where their pricing tiers start to matter.
Used together, the free tools are good for catching the obvious problems before they become expensive ones: a blocked page, a truncated title, a redirect chain nobody noticed, a canonical tag quietly pointing at the wrong URL, or a page failing its Core Web Vitals on mobile without anyone having checked. That is a reasonable use of two minutes, whatever else is on your plate that day.
