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Preview

Quick Reference: Preview

  • Hero Image

    The Preview window shows what LightBurn will send to the laser, with black lines representing cuts and red lines travel.

  • Location

    Main Toolbar

    Window → Preview

  • Keyboard Shortcuts

    Windows: Alt+P

    Mac: Option+P

The Preview window simulates movements and lasering operations before sending a project to the machine. Use it to:

  • See the order in which cuts will be completed
  • Check that your laser will do what you expect
  • Estimate how long a job will take based on the information in the Additional Settings tab of Device Settings
  • Recover interrupted jobs using Start Here

Using the Preview Window

The Preview window is an accurate representation of what LightBurn will send to the laser. Black lines represent cut moves, while red lines are travel moves between cuts.

It's a good practice to check the Preview window before starting any job, to make sure the simulated output matches your expectations, or to identify any problems before it's too late.

To open the Preview window, go to Window → Preview, or click the Preview icon Preview icon in the Main Toolbar, or press Alt/Option+P.

Time Slider

The Time Slider allows you to slide quickly through the project and see the cut order.

Time Slider demo

Job Time Statistics

Below the Time Slider are statistics about the job and the estimated run time. The Additional Settings tab in Device Settings can help you get more accurate time estimates – see the video above for help.

  • Cut distance shows the distance the laser will travel while on, and the estimated time it will take the laser to complete those movements in parentheses.
  • Rapid moves shows the distance the laser will travel while off, between cutting and engraving, and the estimated time it will take the laser to complete those movements in parentheses.
  • Total estimated time shows the combined time it will take the laser to complete all Cut and Rapid moves.

Preview Settings

The settings here only affect the Preview window – they don't change anything about LightBurn's output to the laser.

Setting Description
Playback Speed Sets the speed of playback with the Play button – ranges from ⅕ of actual speed to 5 times the actual speed.
Show Traversal Moves If enabled, shows travel moves in red. If disabled, travel moves are hidden.
Shade According to Power If enabled, uses grayscale shading to indicate higher and lower power cut moves. This only works with the Grayscale Image Mode or Power Scaling.
Invert If enabled, sets cut moves to white on a black background. Useful when engraving on dark surfaces that engrave lighter, such as slate.

Shading According to Power and Invert switches in use

Start Here

Use the Start Here button to recover interrupted jobs by starting the laser at a precise time partway through the operation. Move the Time Slider to the point at which you want to start, then click Start Here.

Save Image

Saves the current Preview as an image file.

Play

Animates the simulation to show the job from start to finish at the speed set in Playback Speed.

Troubleshooting

For more help using LightBurn, please visit our forum to talk with LightBurn staff and users, or email support.