# Crawl comparison

Category: [Monitoring & Alerts](https://seo-geo-glossary.com/en/glossary/category/monitoring-alerts/) › [Types of monitoring](https://seo-geo-glossary.com/en/glossary/category/monitoring-alerts/types-of-monitoring/)

A **crawl comparison** puts the results of two crawls of the same website side by side. The result shows which URLs are new, which are gone and which properties changed.

## What is compared?

Screaming Frog's documentation describes three levels, and other crawlers offer similar views.

- **Changes to elements:** titles, meta descriptions, crawl depth, word count, internal links and content
- **Site structure:** added and missing URLs and changes at directory level
- **URL mapping:** crawls with different URL patterns, for example staging against live, matched with a regular expression

## Where is it used?

A single crawl is a snapshot. Only the comparison shows what changed between two states. That helps after releases and relaunches and as an ongoing check. Whether a difference is a problem still needs a human judgment, since some changes are intended.

## Example

One crawl before and one after a template update show that the title was shortened on 3,000 product pages and the canonical tag points to a different URL on 500 pages. The example is invented.

*Diagram: Monitoring: measure, compare, alert.* Monitoring loop based on practice: fetch again, compare with the previous state, check a rule or threshold. An alert follows only for a relevant deviation, then review and fix. This is not a standard; each team sets its own interval and rules.

## Not to be confused with

- [Change monitoring](https://seo-geo-glossary.com/en/glossary/change-monitoring/index.md): watches a website continuously and reports changes automatically. A crawl comparison sets two specific crawl states side by side, also on demand.

## Related terms

- [Web crawler](https://seo-geo-glossary.com/en/glossary/web-crawler/index.md)
- [Staging crawl](https://seo-geo-glossary.com/en/glossary/staging-crawl/index.md)
- [Change monitoring](https://seo-geo-glossary.com/en/glossary/change-monitoring/index.md)
- [SEO monitoring](https://seo-geo-glossary.com/en/glossary/seo-monitoring/index.md)
- [Crawl frequency](https://seo-geo-glossary.com/en/glossary/crawl-frequency/index.md)

## Sources

- [How to compare crawls - Screaming Frog](https://www.screamingfrog.co.uk/how-to-compare-crawls/)

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Last updated: October 8, 2026
URL: https://seo-geo-glossary.com/en/glossary/crawl-comparison/