NConvert User Guide

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Latest release: 7.12 / Download / May 2017

Download Reference Manual as PDF

NConvert is the multi-format commandline image converter for Win32, Linux, DOS, OS/2, and other platforms.

  • Type "nconvert -help" for available options.
  • Type "nconvert -help > nchelp.txt" to save the help text into the file "nchelp.txt".
  • Convert files to a specific format
nconvert -out tiff file1.pic file2.jpg file3.tga
  • Convert GIF files to JPEG files
nconvert -out jpeg -truecolors *.gif
  • Convert JPEG files to GIF files
 nconvert -out gif -dither -colors 256 *.jpeg
  • Convert with a resize
nconvert -out png -resize 510 230 *.jpeg
nconvert -out png -ratio -resize 510 0 *.jpeg
nconvert -out png -ratio -resize 0 510 *.jpeg
nconvert -out png -resize 200% 200% *.jpeg
  • You can use it with images sequences.
For example, to convert the files file00.pic, file01.pic, ..., file10.pic and we convert to jpeg format with the name pattern res0.jpg, res1.jpg, ... type :
nconvert -out jpeg -n 1 10 1 -o res#.jpg file##.pic
  • You can use % to specify source filename in dest filename.
For example, nconvert -out jpeg -o result_%.jpg file.tga creates a file named result_file.jpg
Note for Windows users: In batch files you must write %% instead of %. To bypass this problem, you can use a nconvert script instead of a batch file.
  • You can control nconvert with a script, performing multiple sets of conversions on multiple sets of files, example:
   ### -out png -rtype lanczos -resize 200% 150% 
screenshot1.bmp screenshot2.bmp screenshot3.bmp ### -out gif -rtype lanczos -resize 500% 500% -oil 10 -colours 32 F:\icons\smile.bmp ### -out bmp -rtype lanczos -resize 30% 30% -oil 2 -rotate_flag smooth -rotate 45 selfportrait.png mydog.png
Save this into a text file, for example "nc.txt", and then run nconvert with this file as the only parameter: "nconvert nc.txt" .


  • Add text feature uses the Win32 API and is avaiable on Win32 only.
  • Some exotical image formats use external DLL's and are available on Win32 only.
  • When using a script file, avoid multiple spaces in the conversion definitions, they confuse the parser.
  • Converting huge images, or scaling up to a huge size requires much memory and may not always work.

Notes for DOS users:

Since version 4.90, nconvert is supported for DOS again. It is a 32-bit DOS application, using the "DOS/32A Extender".