Port 8501Streamlit

Usually the default HTTP port for Streamlit apps; IANA assigns it to CYTEL Message Transfer Management.

transport: tcp
in transit: cleartext
assignment: official
risk: 5/10
lookups: 0

also known as cmtp-mgt, Streamlit server

2 other services are registered on port 8501. compare all 3 →

Technical Details

what runs on :8501

In common deployments, this is Streamlit's web interface: HTTP traffic serves the app, with WebSocket connections used for interactive updates. Streamlit defaults to port 8501; the app may bind only to localhost or be configured to listen on a network interface. Traffic is not encrypted by default, though TLS can be configured or provided by a reverse proxy. This common use differs from the IANA assignment, CYTEL Message Transfer Management.

Security Information

exposure of :8501

risk score

5/ 10caution

worth attention. how exposed you are depends on configuration — don't leave it reachable from the internet without a reason.

web services averages 3.1 across 221 ports — this one sits 1.9 above.

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

An exposed Streamlit server can let unauthenticated visitors use the app and potentially access data or functionality it presents; the impact depends on the app and its data sources. Avoid exposing it directly to the internet without a deliberate access-control design, and use TLS and authentication through the app or a reverse proxy.

Record

iana registry entry

port: :8501
service: Streamlit
transport: TCP
encryption: cleartext
assignment: iana registered
risk: 5/10caution
category: Web Services
usage: Port 8501 is widely used as the default web-server port for Streamlit apps, which present Python data apps in a browser. The IANA assignment is CYTEL Message Transfer Management, but that is not the common reason engineers encounter this port open.
lookups: 0rank 993
added: 2026-10-14
updated: 2026-10-14
references: IANA service name registry — port 8501

Something wrong?

This record is maintained by the engineers who use port 8501. 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 2026-10-14.

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edit this record →back to the registry

Related Ports

all 221 in web services →

the 8 most looked-up other ports in web services — 221 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 :8501Streamlit

Technical Details

Security Information

Related Ports

Port 8501Streamlit