What is Expanse?
Expanse is a security scanner operated by Palo Alto Networks that continuously scans the global IPv4 address space multiple times per day. The scanner identifies and maps internet-facing assets and presences across the internet, typically as part of cybersecurity monitoring and attack surface management services. You can set up Agent Analytics to see when Expanse visits your website.
Overview
| Operated By | Palo Alto Networks |
| Expected To Follow Robots.txt | Yes |
| Insights Last Updated | September 14, 2026 |
Do you operate this agent? Contact us to suggest an update.
Category
Expected Behavior
Expanse's cadence depends on how the scan is configured. Continuous monitoring may run daily or hourly, while a one-time or internet-wide scan may sweep once and disappear.
Expanse's User Agent
| User Agent | Expanse, a Palo Alto Networks company, searches across the global IPv4 space multiple times per day to identify customers' presences on the Internet. |
How To Block Expanse With Robots.txt
Add this rule to your robots.txt file to block Expanse from accessing your website, or use Automatic Robots.txt to block all security scanners at once. You can customize which pages are blocked by swapping out / for a different path.
User-agent: Expanse # https://knownagents.com/agents/expanse
Disallow: /Insights for Expanse
As of September 14, 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
Country of Origin
Robots.txt Blocking Trend
6% of top websites block Expanse in their robots.txts.
Overall Security Scanner Traffic
0.0% of all web traffic came from security scanners.
Frequently Asked Questions
Should I Block Expanse?
Usually not, unless you already run your own security scans and want cleaner logs. Expanse checks for exposed vulnerabilities, and some services report their findings to site owners at no cost. For context, 6% of the top websites we track currently have robots.txt rules for Expanse.
Does Expanse Follow Robots.txt Rules?
Yes. Expanse is expected to follow robots.txt rules, so a disallow rule is the appropriate first step. Automatic Robots.txt can add and maintain that rule, while Agent Analytics lets you verify whether Expanse respects it.
Does Expanse Access Private Content?
It deliberately looks for exposed private content. Expanse tests login pages, admin panels, and API endpoints for vulnerabilities. Probing does not mean it gained access, but you should expect requests to sensitive paths in your logs.
How Can I Tell if Expanse Is Visiting My Website?
Agent Analytics tracks Expanse visits in real time. You can also check your server logs for requests whose user-agent string contains "Expanse". Look for bursts of requests to uncommon paths that ordinary visitors rarely access. Because Expanse does not publish a verification method, any client can claim its identity and a log match is only a clue.
Why Is Expanse Visiting My Website?
Expanse is scanning your site for vulnerabilities, either as part of an internet-wide sweep or because someone requested an assessment of your domain. Recurring visits often indicate that a monitoring service has added your site to its checks.