If you are looking for free pictures you can try unsplash.com.

If you find an image you can go to reduceimages.com to reduce the size so that it will load faster on your website.

Wikipedia says: “Unsplash is a website dedicated to sharing stock photography under the Unsplash license. The website claims over 207,000 contributing photographers and generates more than 17 billion photo impressions per month on their growing library of over 2 million photos. Unsplash has been cited as one of the world’s leading photography websites by Forbes, Entrepreneur Magazine, CNET, Medium and The Next Web”.