I've been trying to make accessible and beautiful GPIO pinouts since I started one for the Raspberry Pi in 2013 [1]. I've since given the Raspberry Pi Pico [2] and Pico 2 [3] microcontrollers the same treatment when they launched.

Recently I've updated these with a new "Upside-down" view to complement the rear view, giving a pinout in the right orientation to match your project.

The Pico sites are all hand-coded single HTML pages with supporting CSS and minimal JS. They are set up to optionally install as a "Desktop" web app. They also degrade into a somewhat usable table in lieu of CSS and use vector graphics (for the board itself) to be viewable and printable at any size.

Finally, hidden behind "Advanced" is a pinout of the test pads and special function pins!

[1] - https://web.archive.org/web/20130505194305/pi.gadgetoid.com/... [2] - https://pico.pinout.xyz [3] - https://pico2.pinout.xyz