My CMS doesn't send Last-Modified. What now?

Configure your server (Nginx, Apache, Cloudflare) to send Last-Modified for HTML responses. WordPress users: install a plugin like "Add Last-Modified Header" or set it in functions.php. The header should reflect the date the content was last meaningfully updated.

How often should I update each page?

Depends on query type. News: weekly-to-monthly. How-to guides: every 3–6 months. Evergreen content: annually. Use Search Console to see which pages are losing impressions — those need updating fastest.

Will faking the update date trick Google?

For a while, then no. Google has explicitly added detection for "fake freshness" — changing the date without real content changes — and pages caught doing this can see ranking drops. Update for real, then update the date.

Does this work without a sitemap?

It falls back to checking just the homepage. For real value, make sure your sitemap is at /sitemap.xml and referenced in robots.txt.

Why are pages without Last-Modified flagged as stale?

Because Google has no efficient way to detect changes to them. Adding the header is a one-line config change and unlocks freshness signals across your entire site.

Free Tool

Updated 6 June 2026

Content Freshness Checker

Find which pages on your site haven't been updated in months. See last-modified dates, age in days, and which pages need a refresh to keep ranking.

By Deepak Shukla — Founder & CEO, Pearl Lemon

Part of Website change detection — the full answer, the facts and the alternatives in one place.

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What This Tool Checks

Last-Modified HTTP header for every page in your sitemap
Pages older than 6 months (stale threshold)
Pages with no Last-Modified header at all (worst case)
Average and oldest content age across the site
Distribution of fresh vs stale URLs

Why This Matters

Google's "Query Deserves Freshness" algorithm explicitly favours recently-updated pages for many query types (news, how-to, software, reviews). Two-year-old content that hasn't been touched gets out-ranked by a competitor's six-month-old article — even if yours was originally better.

How to Fix Issues

1.Update stale top-traffic pages first — biggest ranking lift per hour
2.Add real Last-Modified headers (most CMS-built pages don't send one)
3.Refresh the publish date in your CMS when you update content materially
4.Use schema.org `dateModified` to signal freshness explicitly
5.Set a calendar reminder: every page reviewed at least annually

Stale content is the silent ranking killer. Google's QDF (Query Deserves Freshness) signal means a competitor who updated their article last month will out-rank yours from 2022 — even if yours has better backlinks and more depth. This checker scans your sitemap, fetches the Last-Modified header for every URL, and tells you exactly which pages are bleeding rankings to age.

Why "last updated 2022" is a ranking signal

Google's John Mueller has confirmed many times that freshness matters for queries where users expect current information — "best CRM 2026", "how to install Node.js", "covid travel rules". For evergreen topics like "how does photosynthesis work" freshness matters less, but Google still uses dateModified as a quality signal across the board. The widely-cited Searchmetrics research found that top-3 ranking pages had an average content age of 6 months less than positions 8–10.

Last-Modified — the header most sites don't send

The Last-Modified HTTP response header tells crawlers when a URL last changed. CDNs send it for static files; CMSes usually don't for dynamic pages. Missing Last-Modified means Google has no easy signal of freshness — they have to crawl and diff your content to detect a change, which costs them crawl budget and costs you faster re-ranking after updates. Adding it is a one-line server config change with outsized SEO impact.

What counts as a "real update"?

Google has gotten very good at detecting fake "updated 2026" stamps with no actual content changes. A real update means: meaningful new sections, refreshed statistics, updated screenshots, removed obsolete info, fixed broken links. A 5% content diff plus a date change is enough; a 0% diff with just a date change is detected and demoted.

The 6-month rule

Our default stale threshold is 180 days. This is conservative — for news and fast-moving topics, 30 days is closer to right. For deep evergreen content (history, science fundamentals), 12+ months is acceptable. Tune to your category, but use 6 months as the start.

What to update first

Sort your stale pages by current traffic (Google Search Console > Pages). Refresh the top 10% by traffic first — that's where the ranking lift will be biggest and fastest. Pages with zero traffic can be left alone or considered for noindex/consolidation.

Methodology

We pull your sitemap (or fall back to the homepage if no sitemap is reachable), extract up to 100 URLs, and send a parallel HEAD request to each. We capture the Last-Modified header, calculate the page's age in days, and classify anything older than 180 days as stale. Pages with no Last-Modified header are classified as stale by default — they give us no freshness signal and Google has no easy way to detect updates. We sort results by age (oldest first) so you can prioritise the worst offenders. The check completes in under 30 seconds for most sites and respects a polite rate limit.

Frequently Asked Questions

Monitor this continuously with LemWatch

A one-off free content freshness checker shows you today. LemWatch re-runs the same checks around the clock and alerts you the moment something breaks — free for up to 10 sites, no card needed.