Product Type

Mouse Jiggler MJ-3

Mouse Jiggler MJ-3


Prevent a computer from going to sleep while you work or play


Mouse/keyboard activity emulation dongle; tiny size; works like MJ-1 by default; programmable


Product name Mouse Jiggler MJ-3
Host (I/O) Ports USB type A (m)
Number of LEDs 1
Description of LEDs Tricolor LED (green/red/amber) with configurable functionality
Operating system compatibility Windows XP or later
Windows Server 2003 or later
Mac OS X
Most modern Linux distributions
Bus power Yes
Dimensions 0.71″ x 0.55″ x 0.24″ (18mm x 14mm x 6mm)
Weight 0.05 lbs. (0.02 kg)
Compliancy FCC, CE, RoHS, RCM
Warranty CRU provides a 2-year limited warranty for this product.
Technical Support Your investment in CRU products is backed up by our free technical support for the lifetime of the product. If you need to contact us for any reason, visit or call us at 1-800-260-9800 or +1-360-816-1800.

About Mouse Jiggler MJ-3


The hardware-based Mouse Jiggler prevents your computer from going to sleep while you work or play. This plug-and-use USB device comes in three versions and creates constant mouse activity so your computer won’t go idle and trigger screen savers or sleep mode—eliminating the need to log in repeatedly.


Use the MJ-3 for:


  • Giving a presentation
  • Playing a game like Minecraft
  • Uploading or downloading files, copying drives, or installing updates and programs onto your computer
  • And more!


The MJ-3 is programmable, making it ideal for repetitive IT or gaming tasks. You can create customized scripts with programmed mouse movement, mouse clicks, and keystrokes. The smaller size of the MJ-3 keeps it out of the way and is unobtrusive when installed.


Mouse Jiggler’s small size makes it easy to carry and keeps it out of the way while you work. At roughly the size of a dime – 0.75″ x 0.55″ x 0.25″ (18mm x 14mm x 6mm) – the MJ-3 slips into any pocket. Mouse Jiggler appears as a USB mouse to the host computer it’s plugged into—and its presence and use will be logged by some operating systems. Mouse Jiggler should be used only in compliance with applicable workplace IT policies.


Presenters use Mouse Jiggler because it allows them to present without the screensaver popping up in the middle of the presentation. Employees who are unable to change their system sleep settings or install unapproved software on their computers find Mouse Jiggler convenient to keep screen savers or login screens from activating.


IT professionals use the Mouse Jiggler to prevent password dialog boxes due to screensavers or sleep mode after an employee is terminated and they need to maintain access to their computer.


Computer forensic investigators use Mouse Jigglers to prevent password dialog boxes from appearing due to screensavers or sleep mode. With many computer hard drives now employing full-disk encryption, such modes can greatly increase the time and cost of a forensic investigation. When combined with a WiebeTech HotPlug™, investigators can transport a running computer without shutting it down or worrying about logging in.


Whether you’re a forensic investigator, technician, or IT professional, the CRU WiebeTech Mouse Jiggler is a useful tool.




To automate repetitive or predictable tasks commonly found in IT operations or fun pursuits like gaming, the plug-and-use USB device can be programmed with your scripts to play back keystrokes, mouse movements, and mouse clicks.




The easy-to-use MJ-3 software lets you customize your MJ-3 by helping you create, save, and load scripts for your MJ-3. The free software contains pre-configured scripts and comes in Windows 32-bit, Windows 64-bit, and macOS versions.


  • Programmable! Create custom scripts for mouse and keyboard simulation
  • Temporarily deactivates screen savers for presentations
  • Behaves like an ordinary mouse
  • Forensic use: Pair with HotPlug to prevent computer sleeping