Port Scanner

Probe a host’s port responses using browser requests. Protocols, certificates and browser restrictions affect results; cross-check with server configuration.

Browser Sandbox Security & Scanner Notice

1. 浏览器禁用端口（Unsafe Ports）：现代浏览器出于安全考虑，默认拦截了对某些端口的请求（如 21-FTP、22-SSH、23-Telnet、25-SMTP 等）。这些端口会被标记为“浏览器拦截”，无法从网页端建立连接。如需扫描，请使用本地命令 nmap -p [端口] [目标]。

2. 协议兼容性限制：由于浏览器只能发送 HTTP 族协议请求，对于不响应 HTTP 的非 Web 端口（如 MySQL 3306、Redis 6379），即使端口开放，连接后也会因为协议不匹配返回 fetch 失败（TypeError）。本工具会通过耗时差异进行智能推断，若失败发生在极短时间内（通常 < 15ms），倾向于“关闭”；若有明显延时或异常错误，通常倾向于服务存在但未响应 HTTP。

3. 混合内容安全（Mixed Content）：当本网站以 HTTPS 协议运行时，浏览器默认禁止对非安全 HTTP 的外部 IP 发送请求。但对本机 127.0.0.1 / localhost 拥有豁免权。因此，本工具最适合用于本地开发环境调试。若要扫描公网主机的 HTTP 端口，可能受到混合内容策略限制。

Target Host / IP

Timeout Limit (ms)

Concurrency Workers

Custom Ports Range

Preset Port Groups

Total Scanned: 15

Tool guide

Interpret browser-based port probes

Send browser requests to a specified host and ports, showing response states and timing for connectivity troubleshooting.

How to use

Enter an authorized target, ports and timeout.
Start with a few ports, inspect results and stop if needed.

Example and expected result

Scenario: probe a test host and ports you administer.
Cross-check results with server listeners or a dedicated network tool.

Capabilities and limits

This is not a raw TCP scanner; CORS, TLS, mixed content and blocked ports affect results.
Failures and timing alone cannot prove a port is open or closed.

Troubleshooting

Check protocol, certificates and browser restrictions, then compare with server logs when results disagree.

Data processing and storage

Probes actively contact the target, which may log your network address and requests. This is not only local computation.

Read the full data-processing notice