Website audit: what 8 tools actually check
Every tool on this page will tell you your images are too large. One of them will tell you why the person who read your headline closed the tab.
Short answer
What does a website audit actually check?
Three separate layers, and most tools only cover the first. Technical: can a machine crawl, render and index the site. Product: can a person tell what this is, who it is for and what it costs. Customer: would that person actually sign up and pay. A site can pass the first layer perfectly and still convert nobody, which is why a clean crawl report is not the same thing as a healthy website.
The short version
- Technical layer — speed, Core Web Vitals, titles, duplicates, redirects, structured data, indexability. Covered by all 8 tools compared below.
- Product layer — does the first screen say what this is, who it is for, and what happens next. Covered by 1 of 8.
- Customer layer — would a specific buyer sign up and pay. Covered by 1 of 8.
- Only one tool in this comparison completes the signup itself and reports on what is behind the login, where most abandonment happens.
- Free without an account: PageSpeed Insights, HubSpot Website Grader, GoNoGo Roast.
The three layers of a website audit
These fail independently. A site can score 100 in Lighthouse, have zero crawl errors, rank on page one, and still take no money — because the headline does not say what the product does, or because the signup form asks for a credit card before showing anything. Fixing the first layer does not touch the other two.
Technical
Can a machine read this site?
Page speed and Core Web Vitals, titles and meta descriptions, heading structure, duplicates, redirects, broken links, images, structured data, mobile rendering, indexability. Well served: every tool in the table below does this, and the dedicated crawlers do it exhaustively.
Covered by All 8 tools
Product
Can a person tell what this is and what it costs?
Whether the first screen states what the product does, who it is for, what happens after the button, and what the price is. This is not a matter of taste — it is checkable. Most audit tools skip it entirely, because it is not a crawl signal.
Covered by 1 of 8
Customer
Would this specific person sign up, and would they pay?
The only layer that predicts revenue. It needs someone with a problem, a budget and an alternative to compare against — not a scanner. It also needs someone to go through the signup and see the product on day one, which is where most abandonment happens and where almost nothing is measured.
Covered by 1 of 8
The comparison
Crawl limits and free tiers are taken from each vendor's own page in September 2026. Where a vendor does not publish a number, this table does not invent one.
| Tool | What it looks at | Layers | Behind the signup | Free tier |
|---|---|---|---|---|
| GoNoGo Roast | Up to 40 pages, depth 3, internal links only. Screenshot of every page. | Technical + product + customer | Yes — completes the signup itself and explores what is inside | Free, no account |
| Semrush Site Audit | Whole site crawl | Technical only | No | One check per day, then paid |
| Ahrefs Site Audit | Whole site, 170+ issue types across 19 groups | Technical only | Crawls restricted sites if you hand it credentials — but judges only technical issues | Up to 5K pages a month, account required |
| Screaming Frog SEO Spider | Whole site, 300+ issue types. Desktop software, not a web app | Technical only | No | 500 URLs per crawl, then £199/year |
| Seobility | 300+ factors per page, 50+ reports. Paid plans up to 100,000 subpages | Technical only | No | Separate SEO Checker without registration; full audit needs an account |
| SEOptimer | Single page or full crawl. Adds an AI-search visibility check | Technical only | No | 14-day trial, account required |
| PageSpeed Insights | One URL at a time. Lab data from Lighthouse plus real-user field data from CrUX | Technical only (performance, accessibility, best practices, SEO) | No | Free, no account |
| HubSpot Website Grader | One page. Scores speed and SEO | Technical only | No | Free |
Read the table by the job, not by the score. If you need an exhaustive technical inventory of a large site, the dedicated crawlers win and nothing here competes with them. If you need to know why the traffic you already have is not converting, none of them answer it.
Audit the third layer now
Synthetic personas built from real discussion data browse your site, go through the signup, and report what stopped them. Scores for SEO, performance, mobile, accessibility, trust, copy and conversion, plus a screenshot of every page they saw. Free, no account.
Up to 40 pages · Screenshots of every page · No credit card
What our audit does not do
- It stops at 40 pages and depth 3. On a large marketing site that is a sample, not a full crawl. The cap is deliberate — the decision to sign up is made on a handful of pages — but it means Roast will not find a broken canonical on page 900.
- It follows internal links only. No backlink profile, no referring-domain analysis, no competitor link gap.
- It does not read your server logs, crawl staging environments behind a password you supply, or check hreflang across language versions.
- Its personas are synthetic. They are built from real discussion data, and they are a rehearsal, not a substitute for talking to five actual customers. Use them to narrow what to ask real people.
For the first three, run one of the dedicated crawlers alongside. They are better at that job than we are, and this page links to them directly.
Real audits, published
Every audit can be shared as a public page. Read a few before running your own — the verdicts are unedited, including the ones that scored badly.
Browse published audits →