Plotter file created using the Hewlett-Packard Graphics Language (HPGL); contains a series of two-letter codes, such as "IP," which declares the initial point on a plot; may contain optional parameters with the codes; used by various drawing programs and printers for creating printable plotter documents.

PLT files can be scaled to different sizes without losing quality. They are stored in an ASCII text format. PLT files are the same as .HPG files.

A PLT file is a data file created by Tecplot, a scientific visualization program. It contains output data created through a scientific computation in the software and may contain multiple frames and datasets. PLT files are used for rendering complex 2D and 3D visualizations and may be rendered to a static image or an animated visualization.

Tecplot also offers an ASCII text format for data output. However, this format is discouraged for larger datasets since it renders much more slowly than the PLT binary format in the software.