Do you know how to batch convert images? Do you know how to batch file rename? Do you know which software could batch convert image and rename them at the same time? Here is the answer- IrfanView! This image viewer is a free and powerful tool which can not only view image but also batch convert image and batch file rename.
IrfanView is a fast and compact image viewer/converter. It is trying to be simple for beginners and powerful for professionals. Many supported file formats and features. Features include: multi-language support, Thumbnail option, Painting, slideshow, toolbar skins, fast directory browsing, batch conversion/editing, multipage editing, file search, change color depth, scanning, cut/crop, IPTC edit, capturing, lossless JPG operations, effects, ICC support, EXE/SCR creating, many hotkeys, command line options and plugins.
Guide: How to batch convert image with IrfanView.
Step 1. Start IrfanView
Run IrfanView by double clicking the shortcut. When the interface comes out, press “B” to open the batch conversion window.
Step 2. Select working mode.
On the top left, we can see a panel named “work as”, there are three type of mode we can choose. One is “Batch conversion” which batch convert image format without changing the name. Another one is “Batch rename” which batch rename the image without changing the format. The “Batch conversion-Rename Results files” mode combines those two modes together.
Step 3. Add images
On the the top right of the window, we can explore the images from your computer.
To add one image or some images, we could select the images we want and click “add” button, these images will be added to the file list. Of course, if you want to add all the images in that folder, you can select that folder and click “Add all”. Then all images in that folder will be added in the file list.
Tips: Click 
to list the image by your need rule. Click 
or 
to adjust the position of images in the list.
Step 4. Batch conversion settings
This panel will be disabled if you select “Batch rename” mode. You can adjust the output format here. Click “Options” and “Advanced” for advanced settings.
Step 5. Batch rename settings
This panel will be disabled if you select “Batch conversion” mode. You can set Name Pattern here.
Click “Option” for advanced settings.
Step 6. Output directory settings
This panel you can set the destination of batch conversion files.
Step 7. Start Batch Conversion
Click 
to start the batch Conversion.