How to convert multiple images at once from JPEG to PNG?

How can I convert multiple images at once from JPEG to PNG?

The JPEG to PNG converter on my MacBook does not convert many images quickly at once. My option is now: Convert JPG to PNG - JPG4PNG

What you are looking for is an image conversion software that supports batch conversion, aka batch processing.

Some conversion software has batch conversion built in. Alternatively, you can write a script to control the batch conversion (that is possible for all command line software, but some GUI programs support scripting, too).

There are many programs available, what you should use depends on your requirements (GUI/command line, license, price, etc.). One popular option for a simple, free software, general purpose, cross platform command line image converter is ImageMagick.

You can batch convert images on Mac with Finder:

1. Open Finder and select the images you want to convert.
2. Open them in Preview and then Select All.
3. Go to "File" and choose "Export Selected Images".
4. Choose the export format as PNG.

This tutorial has screenshots:

http://osxdaily.com/2013/01/16/batch-image-conversion-mac-os-x-preview/