Feel free to look around, but these pages are intended for testing, not use, so some of the pages might not make sense.
Solid Color Page: Show a color or alternate between colors.
Latency Test: Check round-trip latency to server.
Time Syncer: Check clock offset relative to server.
Localstorage Editor: Edit cookies, local, and session storage.
Simple Page: Simple page with text only for low CPU consumption.
Big Scroll Area: Configurable tiled page that is very large horizontally and vertically (for testing mouse wheel clicked scroll mode).
Screen Resolutions Representation: Page with regions for different size monitors in pixels.
Error 404 (File Not Found): Page sent when there is a 404 error.
Error 500 (Internal Server Error): Page sent when there is a 500 error.
Error 502 (Bad Gateway; Subserver Offline): Page sent when there is a 502 error due to hosted server unavailability.
Meta Redirect Template: Template for meta redirects. Page will auto redirect by itself by nature so can only be seen with view-source. Additionally, view source links cannot be clicked on, so open link in new tab and refresh instead (or whatever works).
Unicode Character Template: Template for the pages about each unicode character (in beta, accessible here).
Space Lengths: A comparison of different space characters' lengths.
Useful Characters: Some characters that might be useful to copy and paste.