How to Change Security Level in ComfyUI (Full Guide)

ComfyUI is powerful. But with power comes responsibility. Especially when it comes to security. If you are running custom nodes, APIs, or sharing your workflow with others, you need to understand how security levels work. The good news? Changing the security level in ComfyUI is simple once you know where to look.

TLDR: ComfyUI security levels control how much access scripts, nodes, and external connections have. You can change the level by adjusting startup flags or editing the configuration file. Lower security gives more flexibility but increases risk. Higher security keeps things safer but may block some custom features.

Why Security Level in ComfyUI Even Matters

ComfyUI is modular. That means it supports custom nodes. Extensions. Third-party scripts. Even external API calls.

That flexibility is amazing.

But it can also be risky.

If security is too open:

• Malicious nodes can execute unsafe code.
• External connections may access local files.
• Remote users could control your workflows.

If security is too strict:

• Custom nodes may fail to load.
• API integrations may break.
• Development workflows slow down.

The goal is balance.

Understanding ComfyUI Security Levels

Before you change anything, you need to know what the levels actually do.

ComfyUI typically runs in one of several modes depending on how you launch it. These modes control:

• File system access
• External network access
• Execution permissions for custom Python code
• Remote connections to the server

Here are the most common security setups:

1. Default Mode

This is how most people run ComfyUI locally.

• Allows custom nodes
• Allows local file access
• Blocks outside connections unless configured

Good balance for personal use.

2. Safe Mode

Safe mode locks things down.

• Prevents risky code execution
• Restricts certain node behaviors
• Limits potentially dangerous file operations

Best for shared systems.

3. Open / Network Mode

This mode allows external access.

• Other devices can connect
• API calls may work more freely
• Higher risk if exposed to the internet

Great for teams. Risky without protection.

How to Check Your Current Security Setup

You cannot change what you do not understand.

Here is how to check your setup:

1. Open the terminal or command prompt.
2. Look at how you start ComfyUI.
3. Check for startup flags.

If you see something like:

python main.py –listen

That means network access is enabled.

If you see flags related to safety or restricted execution, your security level is modified.

Also check the config files inside your ComfyUI folder. Some versions store options there.

Method 1: Change Security Level Using Startup Flags

This is the most common method.

When you launch ComfyUI, you can add flags that adjust behavior.

Step 1: Locate Your Launch Command

Find how you normally start ComfyUI.

• Windows: check your .bat file
• Mac/Linux: check your terminal command
• Portable builds: look for launch scripts

Step 2: Modify the Flags

Here are useful examples:

• –listen → Allows network access
• –port 8188 → Set a custom port
• –force-fp32 → Not security related, but sometimes seen

If you want stricter security, avoid using –listen unless necessary.

If you want local-only access, run:

python main.py

No network exposure.

Step 3: Save the File

If using a .bat file:

1. Right click it.
2. Choose Edit.
3. Add or remove flags.
4. Save.

Done.

Method 2: Adjust Firewall Instead

Sometimes you want network access. But only inside your home.

In that case, control security at the firewall level.

This gives you flexibility without opening everything.

Windows Firewall

• Open Windows Security
• Go to Firewall & Network Protection
• Allow or block ComfyUI Python access

Router Firewall

Do not port forward unless necessary.

If you must:

• Use password protection
• Limit IP access
• Avoid exposing it publicly

Security is not just software. It is network control too.

Method 3: Disable Risky Custom Nodes

Here is something many users forget.

The biggest security risks often come from custom nodes.

Some nodes:

• Download files automatically
• Execute shell commands
• Call external APIs

If you want higher security:

1. Open your custom nodes folder.
2. Review unfamiliar nodes.
3. Remove or disable suspicious ones.

You can temporarily test security by renaming the custom_nodes folder.

For example:

custom_nodes_backup

Restart ComfyUI.

If issues disappear, a node was the problem.

Method 4: Run ComfyUI in a Sandbox

This is advanced but powerful.

Instead of reducing permissions inside ComfyUI, isolate it.

Options include:

• Virtual machines
• Docker containers
• Sandbox environments

Benefits:

• Separate file system
• Controlled network access
• No risk to main OS

This is ideal if:

• You test unknown nodes
• You develop custom scripts
• You collaborate often

Common Security Mistakes to Avoid

Let us keep you out of trouble.

1. Exposing ComfyUI to the Public Internet

This is dangerous.

Unless you add:

• Authentication
• Reverse proxy
• HTTPS encryption

Never open ports casually.

2. Downloading Random Nodes Without Checking

Only download from trusted sources.

Check:

• GitHub stars
• Recent commits
• Community reviews

3. Ignoring Update Notes

Security patches happen.

Stay updated.

Best Security Setup for Most Users

If you are a solo creator working locally, here is a simple setup:

• Do not use –listen
• Keep firewall enabled
• Install only necessary custom nodes
• Update regularly

If you run ComfyUI for a team:

• Use internal network only
• Protect with firewall rules
• Consider reverse proxy with authentication
• Run inside Docker

If you are a developer experimenting heavily:

• Use virtual machines
• Test nodes in isolation
• Keep backups of workflows

How to Revert Changes If Something Breaks

Security changes sometimes block features.

Do not panic.

To revert:

1. Restore original startup command.
2. Re-enable removed flags.
3. Restore custom_nodes folder.
4. Restart ComfyUI.

Most issues are reversible.

Final Thoughts

Changing the security level in ComfyUI is not complicated.

It comes down to three things:

• Startup flags
• Network access
• Custom node control

Higher security means fewer risks.

Lower security means more flexibility.

You choose what matters more.

If you work alone on your laptop, keep it simple and local.

If you collaborate, think before exposing ports.

If you experiment with random extensions, use a sandbox.

Smart setup. Safe creativity.

That is how you change the security level in ComfyUI the right way.