How to resize multiple images at once

Today I needed to change the size of 20 images for thumbnails and did so one at a time.Then I realised that others might be facing the same issue and there might be some utility to help users modify multiple images at once.

I came across a utility called irfanview which will help us in batch modification of images.You can download the tool here.

Let us see the step by step method of how to change the size of multiple files at once.
1.Install and launch irfanview.( You should see a blank screen after launch)
2.Hit the 'b' key to go in to the batch mode.

3.Select the files you want to change ,by browsing to the folder.
4.Click "Add all" to add all the images from the folder.
5.Select the output directory to place the changed files.
6.Select "Used advanced options" and click on "Advanced" button.

7.Select the re size option you want .Click "OK".
8.Click "Start Batch" and now your changed files will be placed in the output folder selected by you.

The tool also offers many interesting features and you can know about it here.