The Best Stock Images - Free for Commercial Use

While I agree with the general gist of your post --> some of those sites, including Pixabay, offer CC0 (Public Domain Dedication) images which are images released into the Public Domain using the CC0 license. This is a license that allows the copyright holder to waive his or her copyright on an image.

Creative Commons (CC0)

Pixabay FAQ

Pixabay Terms

Pixabay offers some images that are Public Domain and model released which is a quite uncommon. Yes, as part of their ToS they do say no porn or unlawful uses allowed but this is common even with the vast majority of the images you license from reputable stock photo sites. This is not a copyright issue, but a right to control publicity and use of likeness that recognizable subjects of the images hold, and and unless explicitly waived with a proper model release then you should not use images for porn, and of course you are not supposed to use ANY image to break the law no matter where you obtained the image from.

That said, is using free images as good as purchasing a license to use a stock image?

NO. For a couple of reasons... Pixabay takes pretty good care to insure they are actually providing public domain images, but many other sites do not.

What do I mean by this? I mean having a license (and a release if needed) issued by a legit stock photo provider is the best way to go because, as long as you follow the terms of the license, you are off of the hook if someone claims infringement or faulty use down the road. No strictly free image site will give you this protection.

A big problem with some of the free photo sites these days is some of the photos are pirated in the first place and uploaded to the free sites...so you really don't know if you have the rights to use the photo or not.

On top of that a legit stock photo house can provide you images that are model and/or property released and for some uses this is quite necessary. Many uninformed people think the only concern when using photos are copyright...and this is just not the case.

So when you use a photo not only do you have to have a proper license, or a legit public domain photo if you do not want to use a CC attribution license, but you also may need a model and or property release to use recognizable faces, trademarked property, logos etc. in many commercial uses, endorsements, advertisements, marketing materials and in ways that could be considered "false light".

Cheers

-don