How to Free Port 8080 on Mac, Linux & Windows

One command: portrm

$ ptrm fix 8080
  Port 8080 in use
  java (PID 19432) - Spring Boot
  SAFE - development server
  Killed PID 19432. Port 8080 is free.

Free port 8080 on macOS

$ lsof -i :8080
COMMAND   PID  USER   FD   TYPE DEVICE SIZE/OFF NODE NAME
java    19432  dev    56u  IPv6 0x...  0t0      TCP *:http-alt (LISTEN)

$ kill -9 19432
# Or one-liner:
$ kill -9 $(lsof -ti :8080)

Free port 8080 on Linux

# Using ss
$ ss -tlnp | grep :8080
LISTEN  0  100  *:8080  *:*  users:(("java",pid=19432,fd=56))

$ kill -9 19432

# Using fuser (one-liner)
$ fuser -k 8080/tcp

Free port 8080 on Windows

> netstat -ano | findstr :8080
  TCP    0.0.0.0:8080    0.0.0.0:0    LISTENING    19432

> taskkill /PID 19432 /F

What commonly uses port 8080?

Why port 8080 instead of 80?

Port 80 is the standard HTTP port, but binding to ports below 1024 requires root/admin privileges on most operating systems. Port 8080 is the conventional alternative that does not require elevated permissions, making it the default for Java application servers and development environments.

Change the default port

Spring Boot

# application.properties
server.port=9090

# Or via command line
$ java -jar app.jar --server.port=9090

Tomcat

<!-- conf/server.xml -->
<Connector port="9090" protocol="HTTP/1.1" />

Express.js

$ PORT=9090 node server.js