Texture Haven is 100% financed by donations which is the reason there are no limitations. All textures are available in 8K which is more than enough for almost every project for every texture there are AO, Diffuse, Displacement, Normal and Roughness Maps available. The only problem here is that there are only 151 textures available but this will hopefully change soon.

Pixar is one of the biggest contributors in the 3D Community, so they also put out a lot of assets they created for themselves completely for free.

Texture Ninja is with over 2000 Textures the biggest and completely free Texture Library. The only downside is, that image size and quality vary and seamless textures, as well as PBR Textures, are rare.

CC0 Textures is also completly free and no Account is required. It offers over 700 seamless PBR Textures.

3dtextures.me also has a big variety of textures. all made with Substance Designer. Which means all of them are seamless. But to download them in 4K you need to become a Patreon. as a free user, you can only download them in 1K which maybe is not enough for some projects.

textures.com has by far the biggest selection of Textures and gets used by the biggest studios around the globe. They are also offering not only textures but also 3d scans and objects. But you need to have a completely free Account. But to download textures in bigger resolutions you need a Premium Account.

Poliigon is the most premium Resource for Textures and also offers the highest quality assets with a huge variety of different high resolution and seamless Textures. Poliigon also develops PLugins for Blender, Cinema 4D, Maya, and 3Ds Max for faster import.

ThreeDScan offers free high-resolution scans of statues. Which are getting used by many 3D Artists. Every 3D model is completely free and without any copyright restriction. Don’t worry if your browser says, that the site is unsafe this is because there is no SSL certificate on the site.

Casey Cameron who also created HDRI Haven and Texture Haven has now a new project, where he uploads 3D Models completely free to use, Here are also no limitations or anything since the project runs on donations. The only downside is, that you currently can only find 39 models. But I guess this will change soon.

Sketchfab started as a Social Media/ Portfolio Plattform, which enabled people, to upload there 3D Models and Share them with other people. But now it is also a market place to sell 3D models.

This one is only for Blender users. But it is awesome since you can not only download 3D Models you can download entirely .blend files. Which is something, that can be really helpful for beginners, who want to reengineer stuff.

Quixel started by making and selling high quality 3d scans, they also offer a free alternative to Substance Painter have a Bridge App to directly import the Models into Blender and Unreal Engine. Since they were bought by Epic Games, downloading assets with an Epic Games Account is completely free. Especially for building environments, Quixel Megascans is extremely valuable.

Polyhaven is 100% financed by donations, which is the reason there are no limitations. All textures of the HDRIs are high quality and some are even available in 22K, which is more than anyone will ever need. It is also the biggest HDRI library, with over 500 HDRIs.

HDRMaps is the Website with the most HDRIs. They even got used in third-party applications like Substance Painter. and they also offer a lot of freebies.

Pixar also started to create some HDRIs for their Renderman users but of cause you can use them with any Software.

HDRI Skies is specialized in Skys which means they offer the biggest variety of Skys available.