Contents
Give Web-Check one URL, and it collects what can be learned about that website from the outside and puts it on one page. It runs in the browser, so it is an easy way to start checking your own site’s settings.
This review is for people who manage a website for themselves or their company. After reading it, you can do the following:
- Check your site’s certificate, DNS, and security headers in one go
- Spot settings you forgot to configure
- Run Web-Check yourself to check internal sites
What Web-Check is for
According to the official site, Web-Check runs 44 checks in 7 categories. These are the ones administrators look at most:
| Category | Main checks |
|---|---|
| Security | SSL certificate, HSTS, HTTP security headers such as CSP, security.txt, web application firewall |
| Domain | DNS records, DNSSEC, CAA records, WHOIS, subdomains seen in Certificate Transparency logs |
| MX, SPF, DKIM, and DMARC records | |
| Server | IP address, server location, open ports, traceroute |
| SEO and performance | Redirect chain, sitemap, Lighthouse scores |
It also looks up vulnerabilities that Shodan links to the host, data breaches recorded by Have I Been Pwned, and whether the site is on common malware and phishing lists.
Try it safely: check your own domain
- Open web-check.xyz in your browser.
- Enter a domain you manage and run the check.
- Go through the result cards. Start with HSTS, HTTP Security, and Email Configuration. These three often reveal settings you forgot.
Reading the results
| Result | What it means and what to do |
|---|---|
| HSTS is off | Browsers aren’t told to always use HTTPS. Have your server send the Strict-Transport-Security header |
| No CSP or similar headers | Nothing limits which scripts and embeds the page can load. Add headers that fit your site |
| No DMARC | Recipients can’t easily spot mail that impersonates your domain. Add a DMARC record to your DNS |
| Unexpected open ports | A service is reachable from outside. Check it with Nmap and close it if you don’t need it |
Run it yourself for internal sites
The hosted Web-Check checks sites from its operator’s servers. For URLs you don’t want to enter there, such as internal sites, run it in your own environment. With Docker, start it with this command and open http://localhost:3000:
docker run -p 3000:3000 lissy93/web-check
When you run it yourself, environment variables change how it behaves. For example, hosts listed in API_BLOCKED_HOSTS can’t be scanned, and API_DISABLED_CHECKS turns off specific checks such as ports or traceroute.
Cautions
- Don’t check sites you don’t have permission to check. The official fair-use terms ask you not to use it on hosts you aren’t allowed to scan. Some checks send traffic to the target, such as connecting to its ports, tracing the route, and testing a TLS handshake.
- Some checks use data from outside services such as Shodan, SSL Labs, and Have I Been Pwned. Assume the domain you check is passed to those services.
- The hosted version may be rate-limited, and its uptime is not guaranteed. For heavy or work use, run your own copy.
- The hosted version’s operator says it records only the URLs visited and error logs, and doesn’t collect IP addresses or other personal data.
Read next
Sources
- Official repository (README)github.com/lissy93/web-check
- Every check, explainedweb-check.xyz/checks
- About (fair use, privacy, and license)web-check.xyz/about
- Self-hosted setupweb-check.xyz/self-hosted-setup
Checked on 2026-10-25
Similar tools
Nmap
Impact Reaches othersThe standard scanner for finding hosts on a network, the ports they have open, and the services running on them.
- Purpose
- Audit
- Type
- Command line
- Difficulty
- Intermediate
- License
- Check termsNmap Public Source License
- Category
- Network / Reconnaissance
Nuclei
Impact Can harm othersA command-line scanner that sends requests following steps written in YAML templates and checks the responses for known vulnerabilities and misconfigurations.
- Purpose
- Audit
- Type
- Command line
- Difficulty
- Intermediate
- License
- PermissiveMIT
- Category
- Vulnerability scanning / Web security
ZAP
Impact Can harm othersA free web app scanner that sits between your browser and a web app, records the traffic, and looks for vulnerabilities. Formerly OWASP ZAP, now ZAP by Checkmarx.
- Purpose
- Audit
- Type
- Desktop app
- Difficulty
- Intermediate
- License
- PermissiveApache-2.0
- Category
- Web security / Vulnerability scanning