This page is about one tool’s data: the All-in-One SEO Audit. For how it compares with the other two tools, how the scores are distributed and where your own score ranks, go to SEO Score Benchmarks — the methodology and privacy notes live there too.
Which checks fail
This tool runs a single URL through 45 checks. The list below shows the share of audits in which a check did not pass — the higher the percentage, the more widely that item is missing. Items marked “hard fail” cut the score sharply; “partial” ones remove a fraction of it.
| Check | Did not pass | Weight |
|---|---|---|
| Healthy text-to-HTML ratio | 93% | Partial |
| No fixed desktop widths | 87% | Partial |
| llms.txt present | 81% | Partial |
| Clickjacking protection | 74% | Partial |
| HSTS header | 71% | Partial |
| Title length optimal (30–60) | 67% | Partial |
| Extra security headers | 65% | Partial |
| No skipped heading levels | 64% | Partial |
| No broken links | 49% | Hard fail |
| Author & date (E-E-A-T) | 48% | Partial |
| Meta description length (70–160) | 30% | Partial |
| Question-style headings | 28% | Partial |
Which category is weakest?
The audit’s checks are grouped into eight categories. The share below is how often each category came out as the lowest-scoring one in an audit.
The conclusion is clean: the weakest link is content & headings (30%). Performance and indexability were the weakest category in only 1% of audits — hosting and crawling are largely solved, and the work has moved to content structure.
Security headers are still being ignored
Clickjacking protection is missing in 74% of audits, HSTS in 71%, and extra security headers in 65%. All three are a single line of server configuration. They are not direct ranking factors, but they are measured as trust signals and the cost of fixing them is close to zero.
Broken links are the single most expensive mistake
Broken links were found in 49% of audits, and that check is scored as a hard fail rather than partial credit. The average audit carries 10.5 open items in total, but only 0.65 of them are critical. What drags a score down is rarely one catastrophe — it is accumulated small omissions, and a broken link is the heaviest of the small ones.
Frequently asked questions
What is the average SEO audit score?
The arithmetic mean on the All-in-One SEO Audit is 81.8/100 and the median is 86/100. The median is higher because the distribution is stacked toward the top and a handful of very low scores drag the mean down. Compare yourself against the median — with a skewed distribution like this, the average misleads.
Which SEO check fails most often?
The text-to-HTML ratio tops the list at 93% of audits, followed by fixed desktop widths (87%) and a missing llms.txt (81%). The single most costly one is broken links: present in 49% of audits and scored as a hard fail rather than partial credit — so the most common failure and the most expensive one are not the same check.
Are security headers worth fixing for SEO?
They are not direct ranking factors, but the audit scores them as trust signals and they cost almost nothing to add. Clickjacking protection is missing in 74% of audits, HSTS in 71% and extra security headers in 65%. All three are one line of server configuration, and the fact that they are missing this often means easy points are still sitting on the table.
The sample, the methodology, the anonymization and the CC BY 4.0 licence are all set out in the methodology section on the hub.