Port 16021FileMaker Java Web Publishing Core Binary

Port 16021 is assigned to FileMaker's Java Web Publishing Core Binary service and is not commonly seen open in internet scans.

inWeb Services

transport: tcp
in transit: cleartext
assignment: official
risk: 1/10
lookups: 0

also known as jwpc-bin

Technical Details

what runs on :16021

FileMaker Java Web Publishing Core Binary is registered on port :16021 over tcp to Robert Parks, assigned May 2010. We don't have a technical write-up for it beyond the IANA registry entry.

In nmap's internet-wide scan data this port is never observed open, so if it's open on your network it's more likely a custom or misconfigured service than the registered one.

find what's listening on :16021

this machine

# linux
sudo ss -tlpn 'sport = :16021'

# macos / bsd
sudo lsof -nP -i :16021

# windows (then: tasklist /FI "PID eq <pid>")
netstat -ano | findstr :16021

another host

nmap -sV -p T:16021 <host>

run it? the handshake, the implementations you meet in the wild and the flags that matter come from the engineers who do.

add technical details

Security Information

exposure of :16021

risk score

1/ 10safe

routine exposure. this port is rarely the way in on its own — keep it patched and logged and move on.

web services averages 3.1 across 241 ports — this one sits 2.1 below.

in transit

cleartext

credentials and payloads are readable by anyone on path

assignment

official

registered with iana for this service — scanners fingerprint it by number

reachable over

tcp

every listening transport is another surface to filter at the edge

security overview

no security notes recorded for :16021 yet

known exploits, hardening advice, what a compromise looks like — suggest an edit if you know its exposure.

Record

iana registry entry

port: :16021
service: FileMaker Java Web Publishing Core Binary
transport: TCP
encryption: cleartext
assignment: iana registered
risk: 1/10safe
category: Web Services
usage: The IANA assignment describes this as the FileMaker Java Web Publishing Core Binary service. It was registered by Robert Parks; its deployment details are not established here, and it has not been observed open in nmap's internet-wide scan data.
lookups: 0rank 993
added: 2026-10-17
updated: 2026-10-17
references: IANA service name registry — port 16021

Something wrong?

This record is maintained by the engineers who use port 16021. Every field on it is editable — change what's wrong, say how you know, and a reviewer publishes it, usually within a minute. Last touched 2026-10-17.

01edit any field on a page of its own
02a model checks it for accuracy and spam
03clean and confident goes live immediately

edit this record →back to the registry

Related Ports

all 241 in web services →

the 8 most looked-up other ports in web services — 241 ports carry that label.

port	service	proto	category	risk	views
:8888	Sun Answerbook & Alt HTTP	TCP	Web Services	caution	123.9k
:8000	Intel Remote Desktop / Alternate HTTP Port	TCP	Web Services	safe	84.3k
:8888	NewsEDGE	TCPUDP	Web Services	caution	83.3k
:8888	HTTP Alternative Port	TCP	Web Services	caution	76.5k
:8888	GNUmp3d Streaming HTTP	TCP	Web Services	caution	76.3k
:9080	Groove RPC	TCPUDP	Web Services	caution	70.8k
:8881	Atlasz Secure Server	TCP	Web Services	caution	67.6k
:80	HTTP	TCPUDP	Web Services	caution	67.3k

risk mix of the 8 listed

safe13%
caution88%

0 of 8 encrypted

Port :16021FileMaker Java Web Publishing Core Binary

Technical Details

Security Information

Related Ports

Port 16021FileMaker Java Web Publishing Core Binary