# Site health score

Category: [Monitoring & Alerts](https://seo-geo-glossary.com/en/glossary/category/monitoring-alerts/) › [Issues & analysis](https://seo-geo-glossary.com/en/glossary/category/monitoring-alerts/issues-analysis/)

A **site health score** is a single value, usually a percentage, that an SEO audit tool calculates from the issues it finds on a website. It condenses the audit into one number so that changes can be tracked over time.

## How is a health score calculated?

There is no common formula. Each vendor defines its own, and the weighting is often not disclosed. Semrush's documentation for its Site Audit states only that issues are grouped as errors, warnings and notices, with errors named as the most harmful, and that addressing the issues improves the score. The deduction per issue type is not given on the page that was read. Ahrefs does publish its formula: internal URLs without error-level issues divided by all crawled internal URLs, times 100, with warnings and notices not counting. Screaming Frog does not use a single score on its issues overview. It classifies each issue as high, medium or low priority.

Because tools run different checks and weigh them differently, a score of 90 in one tool says little about a score of 90 in another.

## What can a health score show?

- the direction over time within one tool and one crawl setup
- a quick comparison between sections or sites that were crawled the same way

## What can it not show?

- how much the open issues affect traffic or revenue
- whether a few critical pages are broken, since a large number of healthy pages can hide them
- changes in crawl scope, because adding or removing sections changes the base of the calculation (an expected effect of any percentage)

## Example

A crawl of 20,000 URLs shows a health score of 92. After a release, 300 product URLs return a 404 status. Depending on how the tool weighs the issue, the score falls only a few points, although the affected pages earn a large share of sales. The alert on the new errors is more informative than the score.

## Related terms

- [SEO issue](https://seo-geo-glossary.com/en/glossary/seo-issue/index.md)
- [SEO audit](https://seo-geo-glossary.com/en/glossary/seo-audit/index.md)
- [Severity](https://seo-geo-glossary.com/en/glossary/severity/index.md)
- [Crawl errors](https://seo-geo-glossary.com/en/glossary/crawl-errors/index.md)

## Sources

- [Health Score in Site Audit – Ahrefs Help](https://help.ahrefs.com/en/articles/1424673-what-is-health-score-and-how-is-it-calculated-in-ahrefs-site-audit)
- [Site Audit overview – Semrush Knowledge Base](https://www.semrush.com/kb/542-site-audit-overview)
- [Over 300 SEO Issues & How To Fix Them – Screaming Frog](https://www.screamingfrog.co.uk/seo-spider/issues/)

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Last updated: October 7, 2026
URL: https://seo-geo-glossary.com/en/glossary/site-health-score/