This one resembles a black concrete wall when is tiled. It should look great, at least with dark website themes.
Source V. Hartikainen
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
Prismatic Geometric Tessellation Pattern 4 No Background
Source GDJ
Derived from an image that was uploaded to Pixabay by Kaz
Source Firkin
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
This one is rather fun and playful. The 2X could be used at 1X too!
Source Welsley
The image depicts a seamless pattern made using a bird's face.
Source Yamachem
I love these crisp, tiny, super subtle patterns.
Source Badhon Ebrahim
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i
Source Firkin
Utilising a bird from s-light and some flowers from Almeidah. To get the unit tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
A seamless striped fabric-like texture colored in a dark reddish brown color.
Source V. Hartikainen
Number 2 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
Background Wall, Art Abstract, Block Well & CC0 texture.
Source Ractapopulous
Derived from a drawing in 'The Murmur of the Shells', Samuel Cowen, 1879.
Source Firkin
Prismatic Hypnotic Pattern 2 No Background
Source GDJ
Everyone needs some stardust. Sprinkle it on your next project.
Source Atle Mo
Design drawn in Paint.net, vectorised using Vector Magic and finished in Inkscape.
Source Firkin
A seamless pattern formed from background pattern 102
Source Firkin