---
title: "How does Lemwatch monitor XML sitemaps? — Lemwatch Help"
description: "Lemwatch fetches every sitemap and sitemap-index nightly, validates XML, and alerts on 404s, drops in URL count, and stale lastmod dates."
canonical: "https://lemwatch.com/help/sitemap-monitoring"
source: "https://lemwatch.com"
---

# How does Lemwatch monitor XML sitemaps?

> Lemwatch fetches every sitemap and sitemap-index nightly, validates XML, and alerts on 404s, drops in URL count, and stale lastmod dates.

## Quick answer

 Lemwatch discovers your sitemaps from robots.txt, fetches each nightly, validates the XML, and alerts on 404s, sudden URL-count drops (>20%), and lastmod dates older than 30 days.

## What we check

- XML validity and correct namespace

- HTTP status of each sitemap URL (up to 500 per site)

- URL count trend vs last 7 days

- lastmod recency

- Nested sitemap-index resolution

## Where to find it in Lemwatch

 **Site → SEO → Sitemaps** — see every discovered sitemap and its history.

## FAQ

### What is the 500-URL cap?

 We sample the first 500 URLs per sitemap to keep crawl budget sane. Priority pages are picked first.

### Can I add sitemaps manually?

 Yes — paste any URL under Sitemaps → Add.

## Related

- Robots.txt monitoring

- Indexation tracking


## Related

- [Help centre](https://lemwatch.com/help)
- [How does Lemwatch track robots.txt changes?](https://lemwatch.com/help/robots-txt-monitoring)
- [How does Lemwatch track Google indexation?](https://lemwatch.com/help/indexation-tracking)
- [SEO Health Monitoring](https://lemwatch.com/help/seo-monitoring)
- [How does Lemwatch validate canonical URLs?](https://lemwatch.com/help/canonical-url-checks)
- [Lemwatch pricing](https://lemwatch.com/pricing)
- [SLA Dashboard](https://lemwatch.com/help/sla-dashboard)
- [My Site Shows as Down But It's Working](https://lemwatch.com/help/site-shows-down-but-working)