URL: /rules/crawl/sitemap-lastmod-churn

---
title: "Sitemap Lastmod Churn"
description: "Checks that sitemap lastmod values aren't all stamped with the same build date"
---

Checks that sitemap lastmod values aren't all stamped with the same build date

| | |
|---|---|
| **Rule ID** | `crawl/sitemap-lastmod-churn` |
| **Category** | [Crawlability](/rules/crawl) |
| **Scope** | Site-wide |
| **Severity** | warning |
| **Weight** | 4/10 |

## Solution

If every URL in your sitemap carries the same (or nearly the same) lastmod date, the field is being stamped at build/deploy time rather than reflecting real content changes. This makes lastmod useless as a freshness signal - search engines may learn to ignore it entirely. Update lastmod only when a page's content actually changes, driven by your CMS or version control history, not by the deploy pipeline. Google News sitemaps are excluded from this check: they hold only about 48 hours of articles by design, so their lastmod values are supposed to cluster.

## What this rule does not count

**Google News sitemaps are excluded.** A news sitemap (one declaring the `xmlns:news` namespace) carries roughly the last 48 hours of articles by specification, so its `lastmod` values always fall on one or two days. Counting them would flag every publisher that has one. Detection is by namespace, not filename, so a news sitemap served from any path is recognised.

If the only `lastmod` values found on your site come from a news sitemap, the check reports as skipped and says so, rather than reporting a problem you do not have.

The check needs at least 20 URLs carrying a `lastmod` (news-sitemap URLs excluded) before it will judge anything. Below that it skips, because a handful of pages legitimately updated in the same week is indistinguishable from a build stamp.

## Enable / Disable

### Disable this rule

```toml squirrel.toml
[rules]
disable = ["crawl/sitemap-lastmod-churn"]
```

### Disable all Crawlability rules

```toml squirrel.toml
[rules]
disable = ["crawl/*"]
```

### Enable only this rule

```toml squirrel.toml
[rules]
enable = ["crawl/sitemap-lastmod-churn"]
disable = ["*"]
```