How to Audit a Site With Free SEO Tools

A full SEO audit used to mean paying five hundred dollars a month for a SaaS platform. That was 2019. Today every critical check — the ones that actually move rankings — runs in your browser without a credit card. This guide shows you how to run a complete site audit using 13 free tools, in the right order, with the logic behind every step.

The audit covers five phases: overall health, on-page elements, technical infrastructure, content quality, and domain authority. By the end you will have a prioritised action list and a PDF report you can share with clients or keep as a working document.

Key takeaways

• Every tool in this guide runs entirely in your browser — no data is sent to a server or stored anywhere.
• A complete audit takes 45–90 minutes for a mid-size site and surfaces the same issues a paid crawler finds.
• The 45-Point SEO Analyzer is the fastest entry point: paste a URL and have a full score in 10 seconds.
• Fix critical findings — noindex, missing title, mixed content — before touching anything else.
• No single tool does everything. Run all 13 in sequence for a complete picture.
• Domain age, hosting infrastructure, and outbound link quality are the three checks most beginners skip.

Phase 1: Overall site health — the 45-point audit

Start here. The 45-Point SEO Analyzer runs 45 checks across six SEO categories — indexing, search appearance, content structure, mobile readiness, machine data, and link safety — and returns a single weighted score from 0 to 100.

Paste any URL and wait 10 seconds. The score tells you where you stand right now. The breakdown tells you exactly which category is failing and why.

What to look for first:

The critical-issue banner at the top of the report is the most important element. It surfaces findings that cap your score at 65 regardless of everything else — noindex directives, a missing title tag, a missing viewport meta tag, mixed HTTP/HTTPS content, and zero internal links. Fix every critical finding before you do anything else.

After the critical items, read the category scores from lowest to highest. The lowest-scoring category is where your biggest ranking drag lives. If mobile readiness is 40, start there. If content structure is 40, start with the heading audit.

What the score does not tell you:

It does not tell you what your competitors are doing. It does not show you backlink profiles. It does not track ranking changes over time. Those checks require different tools — covered in Phase 5 and the competitive analysis steps below.

Phase 2: On-page elements — every tag that earns or loses clicks

On-page SEO is the discipline of making one page maximally relevant to one query. The two elements that most directly affect whether a page earns a click from the SERP are the title tag and the meta description.

Meta tags — the complete audit

Run the Meta Tag Analyzer on the same URL you audited in Phase 1. It runs 10 fixed checks covering every ranking and social meta tag:

• charset declaration
• HTML lang attribute
• Title tag (presence, length, pixel accuracy)
• Meta description (presence, length, keyword match)
• Canonical tag
• Robots meta directive
• Viewport meta tag
• Open Graph tags (og:title, og:description, og:image)
• Twitter card tags

Each result shows the current value with a pass or fail rating. Every failing tag is a direct ranking or CTR problem — not a theoretical one.

The three meta tag mistakes that cost the most:

A missing meta description is not a ranking factor but it costs CTR. If Google auto-generates the snippet from page content, you lose control over the message. A well-crafted description with a clear payoff gets more clicks from the same ranking position.

A title that exceeds 580 pixels gets truncated in the SERP. Truncation usually cuts the most important word — the primary keyword — from the end of the title. The Meta Tag Analyzer flags titles that exceed the pixel limit so you can shorten before publishing.

A missing or incorrect canonical tag silently destroys link equity. If two pages share similar content and neither has a canonical, Google picks one — usually not the one you intended. The canonical must point to the URL you want indexed.

SERP preview — see it before Google does

Paste the same URL into the SERP Preview tool. It renders the title, URL, and meta description exactly as Google shows them on desktop and mobile. The pixel-accurate display means you see truncation before it happens, not after.

Use the live-edit mode to test revised titles and descriptions. Aim for the primary keyword in the first 40 characters of the title — the part that survives truncation on mobile. The meta description should state the payoff in 150–160 characters: what the reader gets, not what the page is about.

Keyword density — the stuffing, gaps, and over-optimisation check

Copy the body text from your page and paste it into the Keyword Density Checker. It analyses single-word, two-word, and three-word phrases with stopword removal, then scores each phrase’s density as a percentage of total words.

The tool flags three specific problems:

Stuffing occurs when a target keyword exceeds 3% density. At that level, the language starts reading unnaturally to both users and Google’s quality classifiers. This is not a direct penalty trigger in most cases — it is a signal of over-optimisation that correlates with ranking drops.

Gaps are phrases where your competitors rank but your page does not mention the term at all. Run the density check on your top competitor’s page as well and compare the phrase lists. The gap phrases are your content expansion targets.

Over-optimisation shows as a very high density on semantically related terms — not just the exact keyword. Google’s Hummingbird and BERT algorithms read topical relevance across the full vocabulary of a page, not just the keyword phrase. If every other sentence uses the same variant, the page reads as written for algorithms, not readers.

Heading structure — the hierarchy audit

Run the page HTML through the Heading Hierarchy Checker. It runs five focused checks:

1. Exactly one H1 per page
2. No skipped heading levels (H1 → H3 without H2)
3. No empty headings
4. No duplicate heading text across the page
5. Logical heading sequence

Heading structure is an accessibility requirement under WCAG 2.2 — screen readers use heading levels to build a page outline for visually impaired users. It is also an SEO signal: Google uses heading hierarchy to understand the relationship between concepts on a page. An H2 titled “Pricing” beneath an H1 titled “Our Services” reads as a sub-topic of services. An H2 titled “Pricing” beneath an H1 titled “Blog” reads as disconnected.

The most common mistake: using heading tags for visual styling instead of structural hierarchy. An <h2> with bold text is not the same as a genuine H2. The heading checker catches empty headings most sites miss — ones that exist in the HTML for styling purposes but contain no actual text.

Featured snippet eligibility

Run every target H2 on the page through the Featured Snippet Optimizer. It detects whether the query expects a paragraph, list, or table answer from Google, scores the current H2 against seven position-zero rules, and rewrites the heading to match question-phrasing requirements.

The three SERP format signals it checks:

Paragraph format — Google pulls a direct answer from the first paragraph that directly answers the question implied by the query. The H2 must start with a question word or question phrasing.

List format — Google pulls a numbered or bulleted list. The H2 must pose a query where the answer is a sequence of steps or items. The list itself must appear within the first 90 words of the section.

Table format — Google pulls a data table or comparison table. The H2 must pose a comparison or data question. A properly marked-up HTML table within the section increases table-format probability.

Phase 3: Technical infrastructure — sitemap, robots, and DNS

Technical SEO is the discipline that gets your pages found, read, and considered by search engines. A page that cannot be crawled cannot be indexed. A page that renders incorrectly looks different to Googlebot than to a human visitor.

XML sitemap validation

Run the Sitemap Validator on the site’s XML sitemap — typically at /sitemap.xml. The tool parses the full sitemap, flags syntax errors, relative URLs, duplicate entries, invalid date formats, and mixed HTTP/HTTPS schemes.

The three sitemap errors that cause the most damage:

A relative URL in a sitemap tells Google the URL is relative to the sitemap file itself, not the domain. If the sitemap lives at example.com/sitemap.xml and contains a URL like /blog/post, Google resolves it correctly. But if the sitemap contains a bare path without a leading slash, Google ignores the entry.

A lastmod value set to today’s date on every URL tells Googlebot to re-crawl every URL every day. This wastes crawl budget on pages that have not changed and trains Googlebot to ignore the lastmod signal.

A sitemap that lists URLs blocked by robots.txt is a contradiction that wastes crawl budget on pages Google cannot index. Every URL in the sitemap must be accessible to Googlebot.

Robots.txt — build it clean or fix what’s broken

Run the Robots.txt Generator to build a clean robots.txt from scratch, or use it to validate an existing file. The tool checks against the RFC 9309 standard and flags malformed directives as you type.

Every site needs at minimum five things in robots.txt:

1. A User-agent: * block covering all crawlers
2. A Disallow: rule that blocks only the paths that should not be crawled — not entire directories by default
3. A Sitemap: directive pointing to the canonical sitemap URL
4. Correct directive order (User-agent first, Allow/Disallow second within each user-agent block)
5. An end-anchor $ on pattern matches where a prefix should not match a similar path

Domain age and hosting infrastructure

Run the Domain Age Checker on the target domain. Domain age is Google’s oldest confirmed ranking signal — it was embedded in PageRank from the beginning and remains part of the trust calculation.

New domains under 12 months carry an inherent trust deficit that no amount of content quality can instantly overcome. Google has stated explicitly that registration length is a factor in its decisions about whether to trust a new site. Domains registered for 10 years receive a trust signal that one-year registrations do not.

The Domain Into IP Checker reveals the hosting infrastructure. Shared hosting on a known spam or malware IP block carries a reputation risk — even if your content is clean, sharing an IP with a penalised site can cause collateral ranking damage. VPS, cloud, and dedicated hosting remove this risk but do not guarantee better rankings.

Phase 4: Content and schema quality

Structured data tells Google what your page contains in a format it can process programmatically. A page with correct schema markup can earn rich results — expanded listings in the SERP that include images, ratings, FAQs, or step-by-step instructions.

Schema markup generation

Run the Schema Markup Generator to build valid JSON-LD for the page. The tool supports seven schema types:

• Article — for blog posts and news articles. Required fields: headline, image, datePublished, dateModified, author, publisher.
• FAQPage — for pages that answer questions. Renders as an expandable FAQ section in the SERP. Required: an exact match between every question in the JSON-LD and a visible question on the page.
• HowTo — for step-by-step instructional content. Renders with step numbers and optional images.
• Product — for e-commerce product pages. Includes price, availability, and review ratings.
• LocalBusiness — for business locations. Required: address, geo coordinates, opening hours.
• Organization — for company homepages. Links to social profiles and logos.
• Recipe — for food and drink content. Includes cook time, ingredient list, and nutrition facts.

The tool generates copy-ready JSON-LD. Paste it into the <head> of the page before the closing </head> tag. Validate the output with Google’s Rich Results Test before publishing.

Email sender reputation for outreach

Before any outreach campaign connected to the site — guest post pitches, HARO responses, link building emails — run the Email Privacy Checker on the sender address. It resolves the MX record for the domain, looks up the mail server IP, and checks it against 10 major public DNS-based blocklists simultaneously.

A listed IP on even one blocklist means emails from that server will be flagged as spam or rejected by most major mailbox providers. This is not an SEO factor for the site itself — it is an operational check before any outreach effort. Catch a listed IP before sending 200 pitches, not after.

Phase 5: Competitive analysis and link equity

Outbound link auditing

Run the Link Price Analyser on the page. It scores every outbound link on a 0–100 scale using four signals: the nofollow attribute, the link’s position on the page (body links pass more equity than footer or navigation links), the descriptive quality of the anchor text, and the age of the target domain via public WHOIS data.

The tool surfaces three problems that silently drain link equity:

Nofollow links in the body pass no ranking signal to the target page. This is sometimes intentional — linking to a competitor you are citing fairly is a legitimate nofollow use case. But nofollowing every outbound link in the body is a missed opportunity to build relationships and pass equity to trusted sources.

Footer links with generic anchor text waste the most link equity per click. A footer link reading “click here” points to a page with zero keyword context. Change it to “read our guide to technical SEO” and the link now passes topical relevance.

Links to new or untrusted domains with high domain age scores in the target can be valuable — age is a trust signal. Links to brand new domains with no history carry risk: if a link target later receives a manual penalty, links from your page to that domain become guilt-by-association.

How to run this audit in 45 minutes

1. Start with the 45-Point SEO Analyzer on your top 5 pages by traffic. 10 minutes.
2. Run the Meta Tag Analyzer on the same 5 pages. 5 minutes.
3. Check SERP Preview for all 5. 5 minutes.
4. Run the Heading Hierarchy Checker on the most important page. 3 minutes.
5. Validate the Sitemap and check robots.txt. 5 minutes.
6. Run the Featured Snippet Optimizer on every H2 of the top-ranking page. 5 minutes.
7. Check Domain Age and DNS for your domain and 2 competitors. 5 minutes.
8. Run the Link Price Analyser on your homepage. 5 minutes.
9. Export the SEO Analyzer PDF report as a working document. 2 minutes.

Frequently asked questions

Can I really audit a full site without Screaming Frog or Sitebulb?

Yes — for sites under 5,000 pages. The browser-based tools cover every individual URL check that a paid crawler runs on a page-by-page basis. What paid crawlers do that free tools cannot: crawl an entire site in one pass, discover all URLs, map internal link structures, and identify orphan pages. For a full site crawl, run the browser tools on your most important pages and use Google Search Console’s Index Coverage report to find URLs that exist but are not indexed.

Does domain age still matter in 2026?

Yes. Google has confirmed domain registration length as a trust signal since 2012 and has never walked that back. A domain registered for 10 years receives a stronger trust signal than one registered for 1 year. This does not mean new sites cannot rank — they absolutely can, particularly for low-competition queries. But for competitive head terms, the trust advantage of an older domain is a real factor.

How often should I run this audit?

Run the full audit quarterly for established sites. Run it before any major site migration, redesign, or content programme launch. Run the individual tool checks — meta tags, SERP preview, heading audit — on every new page before publishing. The 45-point check takes 10 seconds per URL; make it a pre-publish habit.

Is the SEO Analyzer score the same as a Google ranking?

No. The score is a diagnostic tool, not a ranking prediction. It measures technical and on-page compliance against Google’s documented best practices. A score of 100 does not guarantee a top-10 ranking. A score of 60 with no critical issues can outrank a score of 90 on a poorly optimised competitor page for a low-competition query. Use the score to identify and fix specific problems, not as a proxy for search performance.

What is the single most impactful thing to fix first?

The critical-issue banner in the 45-Point SEO Analyzer output. Noindex directives, missing title tags, missing viewport meta, mixed content, and zero internal links — any one of these is a ranking blocker that no amount of content improvement will overcome. Fix the critical items first, then work through the category scores from lowest to highest.

Wrap-up

Free SEO tools have closed the gap with paid platforms on every individual page check. The tools in this guide — all 13, running in sequence — give you the same diagnostic picture as a £500/month subscription, on any URL, in under an hour.

The discipline is not the tools. The discipline is running them in the right order, acting on critical findings first, and making the audit a quarterly habit. Technical problems compound. A redirect chain added in a migration becomes invisible over time. A canonical tag that drifts when a CMS template updates silently destroys link equity. The sites that consistently rank are the ones that catch the small failures before they become structural penalties.

Run the audit. Export the PDF. Fix what matters most. Repeat every quarter.