What is the fastest way to batch convert NEF files (Nikon RAW) to JPEG?

I'v tried FastStone Image Viewer and Nikon's Capture-DX on my RAM-drive but they appear to be very slow, although Capture-DX uses multi core processing.

The Thumbnail creation from NEF-Files on my Synology's Atom is as fast as my Core i7.

3 Answers 3


You can do it with IrfanView. Do the following:

  1. Download IrfanView
  2. Download the Formats plugin. Note that if you downloaded the x64 version of IrfanView, you will need to download the x64 plugin. This is not obvious from their website! Their plugin page has 32-bit plugins, and a small link to the 64-bit ones, so get those.
  3. Go to File > Batch Conversion/Rename... and add your files to the batch. Don't forget to select a directory on the left, the default is usually not where you want it.
  4. Start the batch.
  • That's the fastest approach so far. If IrfanView would use multithreading, that would be awesome...
    – fubo
    Jun 11, 2019 at 5:27

I shoot in RAW with my Nikon D3100 and used the following to convert images to JPEG format (Ubuntu): "Working with RAW Files" section of this page.

The page shows an example using pnmtopng, which converts the NEF files to PNG, but can be swapped with pnmtojpeg to convert them to JPEG:

  1. Install tools: sudo apt-get install dcraw netpbm
  2. Convert one image: dcraw -c -w input.NEF | pnmtojpeg > output.jpg
  3. Batch convert all in directory: for filename in *.NEF ; do dcraw -c -w $filename | pnmtojpeg > "${filename%.*}.jpg" ; done

It's more than 10 times faster than Imagemagick's morgify and doesn't distort the image.


I haven't tried Gimp batch conversion but I know it can do it. I have used Gimp for other stuff and works great.

Try Gimp. You'll need to get the plug-in for your file format.

Instructions on batch process

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