Unsplash is full of free high-resolution images that you can do what you want with. It’s always my first stop when I’m looking for stock photography and their already large collection is growing constantly. They are very easy to download too, just one click and they’re yours! You will need to edit them before using on your website though as the files are massive – around 2mb normally.
They also offer unsplash.it a service for generating placeholder images. Put your image size (width & height) after the URL and you’ll get a placeholder. If you just want a header for a website and you’re not too bothered what it looks like this is a great tool. For example https://unsplash.it/2000/300 would look good at the top of a website. Change the numbers slightly for a different image – https://unsplash.it/2000/301.
Gratisography offers free high-resolution pictures you can use on your personal and commercial projects, with new photographs added weekly. If you’re after something a bit different, something a bit modern and definitely something that stands out then try this one. Another easy one-click download, but again you’ll have to resize and compress a bit to use on websites.
Pixabay is free, and also includes videos. Easy to search and you can download at different sizes, which can save time on editing them yourself.
Free images for creatives, by creatives, Mourguefile is a community-based free photo site with professionals and amateur photo hobbyists submitting photos. All photos are free for you to download and re-use in your work, be it commercial or not. Quality can vary here so you might have to search, but it’s a good site for if you want something that looks more realistic than professional but posed. One click to download, but these will need editing before use.
Stockvalut has free photos and artwork created by photographers & artists all over the world. They also have free textures and illustrations. Free to download, or you can buy them a coffee!
IM Free is “a curated collection of free web design resources, all for commercial use.” You might have to give attribution to the creator with these so check the licence text next to the photo before using them.
Coverr is a free video site, but very specific in that it has videos for website homepages, with 7 new videos added every Monday. It’s a modern trend where short videos that loop, and usually blurred out, sit behind your homepage text. You will need to know a bit of code, or a web developer, to get these up and running on your website.