PRJ Converter

PRJ to STL, OBJ, STEP, IGES and more. reaConverter processes 3D files for easy 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 March 30, 2026
"reaConverter's automation tools have completely changed how I manage my projects. I often work with large batches of illustrations and used to spend hours converting and organizing them. Now, with Watch Folders, I just set the rules once and everything is handled automatically, exactly how I need it. This is pro-level automation made simple."
Chloe M.
Chloe M.
Freelance Illustrator
"Before reaConverter, I was the ‘File Conversion Guy’ at work — a title I never asked for and definitely didn’t want. Then I found the Watch Folders feature, and suddenly I was free! Now, files convert themselves while I sip coffee and pretend I'm still working hard. My coworkers think I'm a wizard. Thanks reaConverter, for saving my sanity and boosting my fake productivity!"
Ben H.
Ben H.
Overwhelmed Office Hero
"This program is incredibly simple and user-friendly, even beginners can use it with ease. It supports batch processing, works offline, and runs smoothly on my aging Acer Aspire laptop. Best of all, the output quality is outstanding!"
Kevin Harris
Kevin Harris
Happy User
"For cross-platform compatibility, JPEG remains the gold standard. reaConverter’s precision conversions ensure perfect results every time, whether for presentations, websites, or client deliverables."
Paul Baker
Paul Baker
Happy User
"Your solution was buried deeper in search results than it should be. After struggling with unclear alternatives, I found your guides — finally, instructions that made sense for a first-time user like me. Excellent work!"
Richard E. Miller
Richard E. Miller
Satisfied Customer
"Working in a print studio means constantly juggling obscure file formats. I used to waste hours Googling converters or installing random software — until reaConverter became my Swiss Army knife. Install it once, and you're set forever. No internet? No problem!"
Helen Evans
Helen Evans
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  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 

Discover more

Explore our efficient PRJ file converter that saves you time and effort by converting multiple .prj files into different formats.
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