Anyone who likes to mess around with digital images and image editing and who also doesn't want to steal intellectual property is always on the hunt for collections of good, high resolution images that are either in the Public Domain or at least licensed with permission for use under certain conditions (usually attribution/credit). There are many such repositories, some better than others, and listed here are some of the ones I like. I hope you find them as useful and entertaining as I have.
SPECIALIZED - VINTAGE - CURATED
- Picryl
- The Library of Congress - Free to Use and Reuse Sets
STOCK - PNG - VECTOR
- Pexels
- rawpixel
- Pixabay
COMMONS
"A free museum and library exploring health and human experience."
I love this collection. Wellcome has an extensive database of vintage images loosely based on health and the natural sciences. Looking for engravings from the 1700s of the human skull? Look no further. There are modern photographs and scans as well, but it's the historic stuff that gets me excited. Images are usually quite large, somewhere in the 3000x2000 range. Medical paintings, anatomy diagrams, exploded views, taxonomy, specimen illustrations and much more. They also use a "visually similar" suggestion algorithm based on your search result, which can lead to some unexpected tangents. Highly recommended.
Images range from the Public Domain to Attribution license to Attribution/Noncommercial license, so be sure to give credit when credit is due.
"The World's Largest Public Domain Media Search Engine."
PICRYL is an amazingly useful resource for largely historical Public Domain images. Posters, photographs, drawings, paintings, engravings, manuscripts and illustrations. A big part of their value is that they provide curated collections of images, usually with a write up about the collection and what makes it noteworthy. Individual images are also often accompanied by some information, along with the image's source and its copyright status (usually Public Domain). Their database is also searchable by key terms, and each search result spawns thumbnails of related images. All incredibly good stuff.
Of course, PICRYL wants you to subscribe to their service, which means that using their service without registering and paying involves limitations. One is that they require you to select some relevant tags for the image you want to download. The other is that free downloads are limited to medium resolution, meaning usually somewhere around 1024x730. Subscribing gives you unlimited access to original resolution and sometimes very high resolution images, and this meta-collection is good enough that I am seriously considering $7 USD a month. That's saying a lot, because I am notoriously cheap.
"Wikimedia Commons is a media file repository making available public domain and freely licensed educational media content..."
No list of available-to-use media would be complete without Wikimedia. The emphasis here is on "educational," very loosely defined, and the myriad of volunteers who manage and vet the media are very active in their curation. I have my own small presence on Wikimedia, and I have had a couple of interactions with them in which the educational value of images I had uploaded were called into question. Mixed results from those. Regardless, it's an indicator that they take their endeavours very seriously.
Quality and resolution vary wildly, but there are literally many millions of images that are high res and very suitable for use. Licenses vary from Public Domain to Attribution/Noncommercial/No-Derivatives, so please pay attention to what each piece of media requires. Probably my biggest criticism is that the repository suffers from key-term drift, in that the categories that each image is given are determined by the uploader, and the relevance/applicability of those categories is extremely variable; at least the uploader has to choose from existing categories rather than devising their own. Still, one of the best.
Pexels is a great place to find medium-high res photos and video clips that skew towards current trends in stock photography. Lots of happy people in various settings enjoying various activities using various things. There's a lot more than that, though, and some digging around can turn up some really good stuff using a wide range of subjects. Everything is free to use under the condition that a link to the Pexels home page is provided, although it is possible to credit the artist directly. Most photos are somewhere around 2200x1400, which is not bad.
I have a some photos available on the site, and I receive monthly stats about how many views and dls, etc. You can find me here.
"...an online journal and not-for-profit project dedicated to the exploration of curious and compelling works from the history of art, literature, and ideas."
A very intriguing and thought-provoking collection: "With a focus on the surprising, the strange, and the beautiful, we hope to provide an ever-growing cabinet of curiosities for the digital age, a kind of hyperlinked Wunderkammer – an archive of content which truly celebrates the breadth and diversity of our shared cultural commons and the minds that have made it." From what I have seen so far, that seems like a very apt description.
Unfortunately, the images are medium res at best and there is no obvious way to obtain higher res versions beyond going to the source of the images. On the plus side, each collection is presented with a fairly substantial write up. I've only scratched the surface here, though, and the site hosts/links to video and downloadable PDFs of books as well. See, for example, this page about George A. Romero's Night of the Living Dead.
"Free stock photos, PNGs, templates, and mock-ups"
I've only just relented and registered with rawpixel for a free account, and so my experience with them is fairly limited. From what I can gather this morning, however, they are a very wide and diverse resource. Naturally, they want you to upgrade to a premium account, and so images are divided into free and premium categories. Sticking to just the free images though still provides a ton of content. There are traditional stock photos and vintage/historical Public Domain images (e.g., paintings, engravings, etc), but also a lot of design elements in PNG and PSD formats. Sizes are quite large as well, frequently around 3000x2000 at 300dpi or more. And their databases look immense.
They're a bit weaselly, though, when it comes to licensing. Here's their Licensing page, and see if you can figure it out. It looks to me like they are trying to cover their butts while at the same time exerting some intellectual property rights due to their work in creating and maintaining the site. A lot of their Public Domain stuff comes from places like Wikimedia Commons, and if it's designated Public Domain I think you can do with it whatever you want. Other content is trickier, but it's probably safe to take the approach that "You can’t use rawpixel content for prints or other merchandise without adding considerable artistic value."
"Over 2.4 million+ high quality stock images, videos and music shared by our talented community."
I've been aware of Pixabay for a while, and it's a big oversight on my part that I haven't had a close look until now. It's a pretty ordinary stock-photo/vintage/vector compiler (also with music, video, and sound effects), sharing the same space with Pexels and rawpixel. What really sets it apart, though, is the upper limits of resolution that it allows. I think the biggest image I have looked at so far was around 6000x4000, which is pretty great. Importantly, all Pixabay content is free to use for personal and commercial applications, with attribution unnecessary.
I just created an account there and learned that users (at least, free users) are only allowed to upload 10 images a month. That would tend to force uploaders to be picky about what they choose to share. The site is clearly very serious about image quality, as evidenced by their guidelines here. I'm really looking forward to scooping up many very large images from here.
PDP provides a fairly standard mix of vintage imagery and modern stock photography, with a good selection of PNG elements. Using the site for free provides access to medium-high res versions of the images (1920 on the longest side), while premium membership gets you the original/high-res versions. What's different about PDP is that uploaders can make a little money off their work. If someone downloads the full-res "premium" version of one of your photos, you get 6 cents. Even better in my estimation is that each image provides a tip jar for the artist, as well as links to their social media and whatever personal website they want to include. I've started a page there, and I can attest that there is a vetting process that takes a bit, likely increasing the overall quality of the collection.