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+1 (855) 418-2323
File Converters TIFF and PDF apps Forensic FreewareHPGL (Hewlett-Packard Graphics Language) is the standard language for plotters. PLT, HGL, HP, HPL, and PRN files all contain HPGL instructions — pen movements, line coordinates, and pen selections that tell a plotter what to draw. The problem: HPGL files are meant for output devices, not for editing. You cannot open an HPGL file in AutoCAD and modify it as a drawing. To edit plotter data, you need it in DXF — the universal CAD exchange format that every CAD application reads and writes. Total CAD Converter converts HPGL and PLT files to editable DXF in batch, with no AutoCAD required.
(includes 30 day FREE trial)
(only $99.00)
HPGL (HP-GL / HP-GL/2) is a plotter control language developed by Hewlett-Packard. An HPGL file contains pen-movement instructions: pen up, pen down, move to coordinates, select pen, set line speed. Plotters and wide-format printers read these instructions directly to produce output on paper or film. HPGL is a device language — it describes physical actions, not a design. Files with extensions .plt, .hgl, .hp, .hpl, .spl, and .prn typically contain HPGL data.
DXF (Drawing Exchange Format) is an open CAD interchange format created by Autodesk. A DXF file stores geometric entities — lines, arcs, circles, polylines, text, dimensions — as a structured document that any CAD application can read and edit. DXF is designed for human and machine consumption: you can open it in AutoCAD, LibreCAD, FreeCAD, DraftSight, or dozens of other tools, modify the drawing, and save it back.
| HPGL / PLT | DXF | |
|---|---|---|
| Purpose | Plotter output (device instructions) | CAD interchange (design data) |
| Editability | Not editable as a drawing | Fully editable in any CAD tool |
| Content | Pen movements, coordinates, pen selections | Lines, arcs, polylines, text, dimensions |
| Software | Plotters, specialized viewers | AutoCAD, LibreCAD, FreeCAD, DraftSight, etc. |
| Extensions | .plt, .hgl, .hp, .hpl, .spl, .prn | .dxf |
| Use case | Sending drawings to plotters | Editing, sharing, archiving drawings |
Converting HPGL to DXF reverses the output process: it takes plotter instructions and reconstructs them as editable CAD geometry. This is essential when the original CAD file has been lost and only the plotter file remains.
For a folder with hundreds of PLT files, the batch runs in minutes. No user interaction after clicking Start.
Total CAD Converter includes a command-line interface for scripted and scheduled workflows:
CADConverter.exe C:\PlotFiles\*.plt C:\Output\ -cDXF
This converts every PLT file in the source folder to DXF. Other HPGL extensions work the same way:
CADConverter.exe C:\PlotFiles\*.hgl C:\Output\ -cDXF CADConverter.exe C:\PlotFiles\*.hp C:\Output\ -cDXF
Save the command in a .bat file and run it via Windows Task Scheduler for automated conversion of incoming plotter files.
Total CAD Converter handles HPGL as input and converts it to DXF, PDF, TIFF, JPEG, BMP, PNG, WMF, SVG, CGM, and other formats. It also reads DWG, DXF, SVG, CGM, and WMF files as input. One tool covers all your CAD conversion needs.
| Feature | Online Converters | Total CAD Converter |
|---|---|---|
| Batch processing | One file at a time | Unlimited files per batch |
| File privacy | Files uploaded to third-party server | Files stay on your machine |
| HPGL variants | Limited (.plt only) | PLT, HGL, HP, HPL, SPL, PRN |
| Output quality | Varies, sometimes rasterized | Vector-to-vector, editable DXF |
| Command line | Not available | Full command-line interface |
| File size limit | Typically 5–50 MB | No limit |
| Requires internet | Yes | No — 100% offline |
| Price | Free or subscription | One-time $99.00 |
Viewing HPGL files traditionally required tools like CorelDRAW ($449+), TurboCAD ($130+), or ACD Canvas ($599+). Total CAD Converter reads HPGL directly at a fraction of the cost — $99 for a perpetual license.
Total CAD Converter handles HP-GL and HP-GL/2 data in all common container extensions: PLT, HGL, HP, HPL, SPL, and PRN. You do not need to know which variant your file uses — the converter detects it automatically.
Select a folder, click Start, and the converter processes every file without user interaction. For recurring tasks, the command line with a scheduled .bat file handles everything automatically.
The conversion reconstructs HPGL pen movements as DXF entities: lines, arcs, polylines. The output is a real CAD drawing, not a rasterized image. You can edit individual elements in any CAD application.
Personal license: $99.00. Free 30-day trial with no restrictions — no email or credit card required.
Windows 7/8/10/11
"We received a batch of legacy PLT files from a subcontractor — the original DWG files were lost years ago. Total CAD Converter turned them back into editable DXF. The geometry came through accurately, and we could modify the drawings in AutoCAD without re-drawing anything. Saved us at least a week of work."
Erik Johansson Mechanical Engineer
"Our office receives HPGL files from clients who use older plotting systems. We need DXF to integrate their drawings into our projects. Total CAD Converter handles the conversion in batch — I drop a folder of PLT files in and get clean DXF output in minutes. Much cheaper than buying CorelDRAW just to open plotter files."
Angela Bianchi CAD Technician, Progetto Studi
"I used this to convert a set of building floor plan PLT files to DXF so our maintenance team could mark up areas in LibreCAD. The conversion preserved all the line work. Some text came through slightly repositioned, but the overall result was good and definitely faster than tracing the plots manually."
Michael Brennan Facilities Manager
*.plt for automated batches.CADConverter.exe C:\PlotFiles\*.plt C:\Output\ -cDXF. Save the command in a .bat file and schedule it with Windows Task Scheduler for automated conversion of incoming plotter files.
Download free trial and convert your files in minutes.
No credit card or email required.
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