From the About-page:
Photos for everyone
Over 3 million free high-resolution images brought to you by the world’s most generous community of photographers.
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Is it really free? Yes.
Unsplash is a platform powered by an amazing community that has gifted hundreds of thousands of their own photos to fuel creativity around the world. So sign up for free, or don’t. Either way, you’ve got access to over 3 million photos under the Unsplash license—which makes them free to do-whatever-you-want with.
Love the site. I got many pics from it to suebin my personal projects so I could later show them off in my portfolio, some parts of which used to be public, so this really helped me avoid any trouble with licensing or anything.
Sometimes I also get some pics there to turn into wallpapers for my phone or my 16:9 screens.
Absolutely recommended, especially if you need assets for your projects that won’t get you in trouble.