This seamless background image should look nice on websites. It has a dark blue gray texture with vertical stripes, it tiles seamlessly and, like all of the background images here, it's free. So, if you like it, take it!
Source V. Hartikainen
Prismatic Chevrons Pattern 5 With Background
Source GDJ
Background Wall, Art Abstract, Block Well & CC0 texture.
Source Ractapopulous
From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
One of the few full-color patterns here, but this one was just too good to pass up.
Source Alexey Usoltsev
Seamless Prismatic Pythagorean Line Art Pattern No Background. A seamless pattern that includes the original tile (go to Objects / Pattern / Pattern To Objects in Inkscape's menu to extract it).
Source GDJ
Super detailed 16×16 tile that forms a beautiful pattern of straws.
Source Pavel
Could remind you a bit of those squares in Super Mario Bros, yeh?
Source Jeff Wall
A simple example on using clones. You can generate a nice base for a pattern fill quickly with it.
Source Lazur URH
More tactile goodness. This time in the form of some rough cloth.
Source Bartosz Kaszubowski
A free seamless background pattern for use on websites.
Source V. Hartikainen
You may use it as is, or modify it as you like.
Source V. Hartikainen
Utilising some flowers from Almeidah. To get the unit tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Remixed from an image on Pixabay, the original having been uploaded by darkmoon1968.
Source Firkin
From a drawing in 'Cassell's Library of English Literature', Henry Morley, 1883.
Source Firkin
The name alone is awesome, but so is this sweet dark pattern.
Source Federica Pelzel
Here's a quite bright pink background pattern for use on websites. It doesn't look like a real fur, but it definitely resembles one.
Source V. Hartikainen
To celebrate the new feature, we need some sparkling diamonds.
Source Atle Mo
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin
Remixed from a drawing in 'Chambéry à la fin du XIVe siècle', Timoleon Chapperon, 1863.
Source Firkin
A web texture of brown canvas. Will look great, when used in dark web designs.
Source V. Hartikainen
Feel free to use this seamless background texture as a background on a web site. It's colored in a light pink color and is seamlessly tile-able.
Source V. Hartikainen