How to use Web VNC

Web VNC lets you access VNC-type devices (like QEMU virtual machines, Docker, and other emulated devices with a desktop) directly in your browser. You do not need to install VNC client software.

Quick Start

Open Web VNC

Right-click on a VNC-supported node and select "Web console(inline)" to open an inline Web VNC window. Or select "Web console in new tab" to open it in a new browser tab.

The Web console(inline) window opens in the topology interface. You can drag, resize, move, or minimize it.

note

Window limits:

• Minimum size: 500×400px
• Maximum size: No hard limit

Features

Connection Management

Auto-connect:

• When you open a VNC console, it connects to the device automatically
• There is a 15-second connection timeout for protection

Connection states:

• Connecting
• Connected
• Disconnected

Screen Control

Zoom features:

Action	Description
Zoom in	Make the display bigger
Zoom out	Make the display smaller
Fit to window	Adjust automatically to fill the window

Fullscreen mode:

• Press F11 or click the fullscreen button to enter or exit fullscreen
• Hides the browser frame for a full-screen experience

Send Keys

Send special key combinations to the device (to avoid conflicts in the browser):

Key	Function
Ctrl+Alt+Del	Send Ctrl+Alt+Del
Ctrl+Alt+Backspace	Send Ctrl+Alt+Backspace
F1 to F12	Send function keys
Tab	Send Tab key
Esc	Send Esc key
Print Screen	Send Print Screen key

note

Combination keys are supported, for example Ctrl+Shift+F1.

Screenshot

• Click the screenshot button
• The screenshot is automatically downloaded as a PNG file
• Captures the current VNC screen content

Screen Recording

Recording modes:

Mode	Description
VNC	Record only the VNC screen
VNC+Camera	VNC screen with camera picture-in-picture (bottom-right corner)
Camera	Record only the camera

Recording features:

• Format: WebM
• Pause/Resume: You can pause the recording at any time
• Audio recording: Supports microphone recording (can be muted)
• Visual effects:
  • Timestamp overlay
  • Mouse cursor display
  • Click ripple animation
  • GNS3 watermark (invisible digital watermark)

Recording behavior:

• If VNC disconnects, the recording continues (may show a black screen)
• Paused time does not count toward the recording duration

Clipboard Sync

Send clipboard:

• Paste local text into the VNC device

note

VNC Clipboard Support by Platform

Platform	Clipboard Support	How It Works
Docker	Full support	TigerVNC + vncconfig
QEMU	Partial support	QEMU built-in VNC, depends on guest system

Comparison with Traditional VNC Clients

Feature	Web VNC	Traditional VNC Client
Installation	No installation needed	Needs VNC Viewer
Cross-platform	Any modern browser	Depends on operating system
Recording	Built-in recording	Needs extra software
Screenshot	One-click screenshot	Needs extra steps
Camera	Supports picture-in-picture	Not supported

Feature Contributor

Web VNC feature was developed and contributed by YueGuobin.

• LinkedIn: Guobin Yue