Changing the type or size of multiple image files at once

When working with different image files you may need to change the size, format, or other settings of multiple images to allow them to work with a website, fit onto a CD, mail them to your friends or family, etc. Unfortunately, when working with dozens or even hundreds of different files, it can be very time consuming to open each of the files manually and change them.

Thankfully there are free image programs, such as IrfanView, that allow you to run a batch conversion to change almost any setting of the images into another setting in a few seconds. Below are steps on how you can use IrfanView to change the type, size, or other settings of multiple image files all at once.

  1. Download and install IrfanView onto your computer. You can find a download for this program at:
  2. Open the program once installed on your computer.
  3. In IrfanView, click File and select 'Batch Conversion/Rename'.
  4. In the Batch conversion window, browse to the location of your image files, select each of the images you want to convert, and then click the Add button to add the files to the input files.
  5. If you do not want the new image files to be placed in the C:\TEMP directory, specify a new output directory.

Irfan view batch multiple image convert

Change format

Once the files have been added, if you're changing the image files to a different format, change the Output format to BMP, ECW, EMF, GIF, ICO, JP2, JPG, JPM, LDF, LWF, PCX, PBM, PGM, PNG, PPM, RAW, TGA, or TIF.

Change size

If you need to change the size of each of the files to a new size, click the 'Set advanced options' button, check the RESIZE box, and specify the new width and height. If you want to reduce the percentage size of the image select the 'Set new size as percentage of original' option instead.

Tip: We always suggest also checking the 'Use Resample function (better quality)' box also when resizing images as it can greatly improve the quality.

Change the name of all the files

If you also need to change the name format of each of the files, you can also select the 'Batch rename' or 'Batch conversion - Rename result files' option and specify the name pattern you want to use for the names of the new files.

Once you have specified all the changes you want to make during the batch conversion, click the Start button in the Batch conversion window.

Start the process

Tip: Click the Options button next to the Output format section, and make sure the image quality is set to the maximum to help prevent any decrease in image quality.

Once you've adjusted all the settings you want to do in the batch process click the Start button.