How to find free images?

The question is often advisable to add images to his articles. This contributes to the success of some blogs. But how to find a picture to illustrate each page?
We want not to purchase images whose origin is not known ...

Making a search the simple way

Go to a specialized site:

Librestock.com

and type your request. 50 000 high quality public domain pictures are available.

Making a search the hard way

The best source is the search engine Google Images.

"The most comprehensive image search on the Web."

Google has created options for rights in its image search engine.
The Advanced Search interface offers a range of options to refine your search, including options about copyrights and right to reuse.
This may be defined in the query too, based on the following parameters:

You have this choice of filters (providing the engine still support them): 

&as_rights=cc_publicdomain
&as_rights=cc_attribute
&as_rights=cc_sharealike

So if you're looking for royalty-free images about "programming", the request will be:

http://images.google.com/images?q=programming&as_rights=cc_publicdomain

In a group keywords are separated by the %20 code, example:

programming%20php

Using an innovative tool

The Wikiview tool offers a simple way to navigate a stock of images by presenting them in a sphere in 3D, in the stock of the Wikimedia Foundation, Commons.
The images are royalty-free, but there may be a more restrictive license, to view on the image page.

Wikiview3D sphere of images

Using an image generator

It is also possible to automatically create images, with the guarantee that they will be unique!

Microsoft has added its DALL-E image generator tool to the Bing browser. Just go to the following address and enter the description of the image you want to create, then download the created work.

Going directly to sharing sites...

Some sites provide lots of images and icons available for free...

See also