PRJ Converter

PRJ to STL, OBJ, STEP, IGES and more. reaConverter processes 3D files for sharing across different platforms.

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PRJ Files
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PRJConverter

How to Convert .prj Files in Bulk

1. Install reaConverter

Download reliable PRJ conversion software to convert multiple .prj files and folders in one go.
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Install reaConverter

2. Select PRJ Files

Select PRJs from a folder or drag and drop them into reaConverter, then choose the desired output format.
reaConverter - Load PRJ files

3. Start Conversion

Click Convert to start the bulk conversion of all selected PRJ files. The process will begin right away.
reaConverter - Start PRJ conversion

Convert PRJ on your PC

For quick and effortless PRJ file handling on your PC, reaConverter offers powerful conversion tools with batch processing. Best of all, it works entirely offline — ensuring your sensitive data never leaves your computer.

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Do more with your files

Converting PRJ files for use in a larger project? reaConverter offers many ways to process files, so you can customize them according to your requirements.

Our range of editing options includes auto-processing options such as auto-rotate, auto-crop, watermarking and more. Change Color Space, copy Metadata, set DPI, manage ICC Profile, control Bit Depth.

Conversion features
Image editing

User Reviews

Average User Rating:
Last updated on May 31, 2026
"An excellent program! I use it regularly in my work - it supports nearly every file format imaginable. The interface is intuitive and runs flawlessly every time."
Roger Cook
Roger Cook
Happy User
"I deal with hundreds of images daily, and reaConverter has been a lifesaver. The Watch Folders feature lets me automate file conversions without lifting a finger. I set up a folder for incoming files and it automatically resizes, renames, and converts them into the formats I need. It's like having a personal assistant!"
Sarah T.
Sarah T.
Graphic Designer
"This software just works! My old laptop can’t handle Photoshop, but reaConverter flies through conversions without breaking a sweat. Wi-Fi gone? Still strong!"
Robert Williams
Robert Williams
Happy User
"An efficient all-in-one solution for image conversion and light editing, designed for maximum user-friendliness."
Elena Anderson
Elena Anderson
Happy User
"Finally an app that actually opens my weird files! Saves me from format frustration daily."
Kyle Brooks
Kyle Brooks
Happy User
"I was skeptical at first, but reaConverter exceeded my expectations. The interface is intuitive, and the advanced settings let me tweak outputs perfectly. Plus, the customer support is fantastic!"
Sarah Lane
Sarah Lane
Satisfied Customer

PRJ files: Frequently Asked Questions

What are PRJ files?

The PRJ extension is attached to project files created with 3D Studio, the predecessor of 3ds Max, created for operation on the DOS platform. PRJ is also known as a mesh file, containing graphical data related to geometry, texture, lighting and other relevant info associated to a 3D model.

Can reaConverter open PRJ files?

reaConverter fully supports the PRJ file format – open, edit, and export PRJ files to any other popular file format with ease.

How do I change PRJ to another format?

reaConverter is a user-friendly tool for converting PRJ files. Once installed on your computer, it allows you to convert all your .prj files at once with just a few clicks. You can even convert prj images directly from Windows Explorer using the right-click menu — fast and convenient.

Can I convert PRJ online?

If you only want to convert a few PRJ files, you are welcome to try our free online PRJ converter.

How can I turn PRJ files on my computer to another format?

The best way to convert PRJ files on your PC is to get a quality piece of software, such as reaConverter. This software is extremely efficient in managing a wide range of batch files conversions, including conversion from PRJ.

How can I automate PRJ files conversion?

reaConverter supports all the essential automation features, such as right-click сonversion and Watch Folders, for the most efficient automated file conversion in any software of its kind.

Can I convert PRJ files using scripts or the command-line interface?

reaConverter provides full access to all its features from the Windows command-line shell, including the command-line prj converter.

What else can I do with reaConverter?

Convert DICOM filesResize pictureConvert PDF filesWatermark imagesConvert vector files

What formats can I convert a PRJ file to?
ai  apng  avif  bmp  bpg  cal  cg4  cgm  cin  cit  dcm  dcx  dds  dgn  dis  drw  dwf  dwg  dxf  emf  epi  eps  fax  fits  flif  gbr  gif  glb  gltf  hpg  hru  ico  iff  iges  igs  jp2  jpeg  jpg  jxl  jxr  mif  mtv  pcl  pct  pcx  pdf  pgm  pic  plt  png  ppm  prc  ps  psd  qoi  qrt  rad  rla  sgi  shp  step  stl  stp  svg  svgz  tga  tif  tiff  u3d  webp  webpll  wmf  wmz  wpg  wrl  x3d  xbm  xpm 

Beyond PRJ conversion

Convert .prj files in batches of any size, with editing and processing applied along the way. The same tool also handles 700+ other formats, including CAD, medical imaging, and GIS.
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Free trial · Windows 10/11 · 64-bit · v8.0.240 · Files never leave your computer
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