How do I batch convert JPG to PNG on Mac?

dialabrain wrote:

See: How to Batch Convert Images Using macOS Preview

That Preview.app batch convert option is buggy in Ventura and Sonoma. It exports files having the desired suffix (.png, .pdf etc) but often only the very 1st file is really the desired codec and the rest have really another codec (the last time I tried in Sonoma exporting as .pdf was really TIFF codec in the last exported files, and now in Ventura exporting as .png was really JPEG codec in the last exported files).

On the other hand, Finder's Quick Action batch > Convert Image > to PNG seems to work OK at least in Ventura.

See: How to Batch Convert Images Using macOS Preview

If you're into dedicated apps, ImageMagick is one of the most powerful options. It's a command-line tool, but very handy for you to batch convert jpg to png on Mac. By the way, ImageMagick is super fast and flexible, plus it can handle pretty much any image conversion you throw at it. The command-line interface might be a bit daunting if you aren't used to it, but once you get the hang of it, it's a breeze!

ttstackon wrote:

I understand that PNG is a lossless format, but I want to ensure that the conversion doesn't degrade the quality of my images.

No need to worry. Your PNG images will accurate reproduce the limited colour range of the JPEG images and all the JPEG image artifacts.

ttstackon wrote:

I need some assistance with batch converting a large number of JPG images to PNG format on my Mac.

Something that should be mentioned. There is zero benefit in converting .jpgs to .pngs. There is no quality improvement and the resulting .png file size would be 2 to 8 times larger, depending on the image.

As imagemagick is not provided as a downloadable, pre-built package, and it is a bone-yard of dependencies on other libraries, building it manually on macOS is a nightmare. Then, if one looks at building it in homebrew (and I have) one can see just how deep those dependencies go visually (without actually installing it):

brew deps --tree --installed imagemagick

And that tree continues to grow as new dependencies that are dependent on other dependencies expands. Powerful tool, but you pay for it in complexity and overhead.

Etresoft sort of touched on that in his post…

Yep. I realized that's what he was getting to once I had my coffee.

😉 Just finished a second cup of dark roast myself…