What is W3C-checklink?

W3C-checklink crawls websites to validate links and anchors, checking for broken links, redirects, and link conformance to web standards. Agent Analytics can track when it visits your website.

Overview

Operated By W3C
Source Official Website
Expected To Follow Robots.txt No
Insights Last Updated August 11, 2026

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Category

Developer Helper
Assists with testing, debugging, and ensuring website functionality

Expected Behavior

W3C-checklink's traffic often follows fixed intervals like a cron job. Activity may consist of short recurring checks or occasional intensive bursts, but it usually remains limited to a specific set of pages or endpoints.

W3C-checklink's User Agent

User Agent W3C-checklink/5.0.0

How To Block W3C-checklink With Robots.txt

Add this rule to your robots.txt file to request that W3C-checklink not access your website, or use Automatic Robots.txt to request the same of all developer helpers at once. You can customize which pages are blocked by swapping out / for a different path.

User-agent: W3C-checklink # https://knownagents.com/agents/w3c-checklink
Disallow: /

Global Statistics for W3C-checklink

As of August 11, 2026, this data reflects agent visits measured across thousands of websites using Agent Analytics, combined with daily scans of the top 1000 websites and their robots.txt files.

Robots.txt Blocked Percentage

0%
0% of top websites are blocking W3C-checklink
Learn How →

Country of Origin

United States
W3C-checklink normally visits From the United States

Robots.txt Blocking Trend

0% of top websites block W3C-checklink in their robots.txt files.

Overall Developer Helper Traffic

0.3% of all web traffic came from developer helpers.

Frequently Asked Questions

Should I Block W3C-checklink?

Only if no one on your team relies on it. W3C-checklink may support uptime monitoring, performance tests, or audits. Blocking it without checking first can silently disrupt those workflows. Almost none of the top websites we track currently have robots.txt rules for W3C-checklink.


Does W3C-checklink Follow Robots.txt Rules?

No. W3C-checklink is not expected to follow robots.txt directives, so a disallow rule only communicates your preference. Enforce the block with firewall or server rules, then use Agent Analytics to verify that its requests stop.


Does W3C-checklink Access Private Content?

Only when configured with access. A team may grant W3C-checklink credentials to monitor staging sites or private health endpoints. Without those credentials, it sees only public pages.


Why Is W3C-checklink Visiting My Website?

Someone, most likely on your own team, configured W3C-checklink to check your site. Uptime monitors, performance testers, and audit tools visit only the sites or endpoints they are told to watch.


How Can I Tell if W3C-checklink Is Visiting My Website?

Agent Analytics tracks W3C-checklink visits in real time alongside every other known AI agent, crawler, and scraper. You can also check your server logs for requests whose user-agent string contains "W3C-checklink". Look for repeated checks of the same pages or endpoints at regular intervals. Because W3C-checklink does not publish a verification method, any client can claim its identity and a log match is only a clue.