Free content

Audio

This is what I actually do with my life, so I know too much of it to fit here. See sample libraries, musical corpora.

Images

In descending order of addictiveness:

• Internet archive book images on Flickr are my favourite and have an elegant origin story. They are my primary source of illustrations on this blog. For example, Jan David’s 1603 classic Christeliicken waerseggher images are wildy tripped out. AFAICT they have stopped updating Flickr though and you might need to read books for the latest ones.
• British Library collection.
• British Museum collection.
• Paris Musées have 100000 artworks for use apparently.
• Paul K/Bibliodessy lovingly hand-curates classic book images. Peking opera figures? Baltic Heraldry? The Astrolabe Molluscs?
• unsplash is community driven copyleft photos
• picryl is a paid service that indexes public domain images. High resolution images are pay-for-download and the rest are free. I could give them USD7/month for the high-resolution or you could use their search index and then use a reverse image search such as tineye to find a higher resolution version. Some of the other providers here share their collections through Picryl - IIRC, NYPL does. The search function is good enough that it seems like value for money.
• The Smithsonian Institution images are a high profile open access launch.
• Metmuseum Open Access has a 400,000-strong open access public domain art image collection. Resolution tends to be low. Photographs professional, though.
• erara the incredible library of ultra-high=resolution loginvgly digitised manuscripts and prints.
• Google arts and culture indexes some collections, including e.g. the Rijksmueum. The search function is inaccurate but serendipitous; I usually find something better than what I searched for.
• Old book illustrations lithograph curation is good, although you must pay $15 a month to get access to many full-res versions.
• NYPL collections are good but not all full resolution without a fee.
• Library of Congress Picture collection.
• University of Chicago overview.
• Biodiversity Heritage Library has nature sketches and such.
• viaLibri is a search engine for actual physical books, but sometimes includes lavish high-resolution previews. Try Rare books from 1621.

Books

One of the many wonderful features of the Internet Public Library is not its browsing page, which is a mess. I laboriously opted in to all the old (hopefully uncopyrighted) books by clicking checkboxes.

Clip art and icons

• undraw is one source. From the Hacker n00bs thread we also find…
• The Noun project
• FreeSVG
• Ouch! is a bunch of quirky/chunky illustrations of common situations for your quirky/chunky website.
• Humaaans provides paper-doll identikit people
• So does fresh folk.
• illustrations.co is a 100-illustrations-in-100-days thing
• Isometric does isometric illustrations. That is kinda my jam.s
• Glaze: stock vector illustrations via crowdsourcing and profit-share
• Lukasz Adam is a productive solo illustrator’s loss-leader

3d models

• Redwood data, A Large Dataset of Object Scans
• Smithsonian 3d models

Film

• World’s cinema has copies of many art-house films. Provenance unclear and thus suspect.
• content on torrent aggregators like torrends.to, thepiratebay.net, demonoid.is, ww1.1337x.buzz/1337x.to and rarbg.to is not necessarily going to be violating copyright, but in practice, 90% of the content one finds there will be in violation, and it is best to steer clear.

General

• Open Culture tracks “675 Free Movies, 550 Free Audio Books, 600 Free eBooks, 170 Free Textbooks, 300 Free Language Lessons…”. AFAICT everything here is legit but once again, be careful and check the laws in your jurisdiction.