Open PLT files in your browser
The language of HP's pen plotters, which CAD apps, cutters and engravers still write. Open a plot right here, drawn pen by pen. Nothing leaves your device.
Or drop it anywhere on this page
What you'll see
Your plot opens drawn on white paper, each pen in its color, with its pens listed in the panel beside it.
- Every line in its pen's color • Sharp at any zoom
- Pens • Hide a pen or show one alone
- Measure in millimeters • Its size, pens and labels
- Export • PDF, PNG or SVG
About PLT
HP made HP-GL in 1977 for its pen plotters: two letter instructions that pick a pen, lift it or put it down and move it, draw circles and arcs and write labels in a stick font. HP-GL/2 came with the DesignJets in 1991, adding pens' widths and colors, fills and a compact way to write coordinates.
AutoCAD, CorelDRAW and other apps write PLT files when they print to a plotter's driver, and vinyl cutters, laser engravers and sign making software read and write them to this day. Nothing on Windows, macOS or phones shows one, so it usually goes to a plotter or cutter as it is.
Filepeek draws the plot in your browser on white paper, each pen a layer in its color, its labels in the stick font, at its true size in millimeters. Hide a pen or show it alone, Measure between two points, see its size and pens in Show details, and Export it as PDF, PNG or SVG.
HP-GL plot file
.plt • .hpgl • .hgl
Format
- MIME type
- application/vnd.hp-hpgl
- Made by
- HP
- Released
- 1977
Inside the file
- Pens
- Each with its color and width
- Instructions
- Two letters and numbers, like PU, PD, CI and LB
- Units
- Plotter units, 1,016 an inch
- Labels
- In the plotter's stick font
Opens in every browser
Filepeek opens HP-GL and HP-GL/2 plots in Chrome, Edge, Firefox and Safari. On their own, browsers download them, and Windows, macOS, iOS and Android need a CAD app or a plot viewer to open them.
- YouChromeOpens through Filepeek
- YouEdgeOpens through Filepeek
- YouFirefoxOpens through Filepeek
- YouSafariOpens through Filepeek
Apps that open PLT
- WindowsNo app built in opens it • CAD apps, like AutoCAD, or a plotter
- MacNo app built in opens it
- iPhone and iPadNo app built in opens it
- AndroidNo app built in opens it
Questions
Why aren't my plot's colors the ones I chose?
HP-GL keeps only pen numbers, and the colors were the pens loaded in the plotter, so a plot that doesn't set them is drawn in HP-GL/2's own: pen 1 black, 2 red, 3 green, 4 yellow, 5 blue, 6 magenta and 7 cyan. Most apps' HP-GL/2 plots set their colors and show in them.
Is every .plt file a plot?
No. gnuplot names its scripts .plt too, and some cutters keep formats of their own under that name. A PLT that isn't HP-GL opens as text, or shows its About card.
Can I turn a plot into a PDF or SVG?
Yes. Choose Export, then Save as PDF, or Save as SVG to keep it as lines for a vector app or a cutter.
Why does my PLT open on a map?
A .plt that starts with OziExplorer Track Point File is OziExplorer's track, a GPS log rather than a plot, so it opens on the map with its heights and times.