Yes, if you play the games on your browser (that is, if you just use the http.server module of Python 3 or the similar, but less powerful module of Python 2), your progress data are in the cache browser.
If you want to inspect your progress, press F12 (open the JS console) and go to:
- Application -> Local Storage (on Chromium-derived browsers)
- Storage -> Local Storage (on Firefox)
then find the game URL (for instance
You must be registered to see the links
) and finally select the key, aka the save slot.
Saves may be called, for instance, RPG File1, RPG File2: but this depends on the game.
In the attached screenshot, I have saves from The Passage, Fake AI, Free Cities, Whoremaker and what not. Some are compressed, some aren't (saves from RPG Maker are usually compressed iirc).
Physically your browser cache is located in
~/.config/google-chrome/Default/Local Storage/leveldb
(if you use Google Chrome) but you won't find any .rpgsave file in that directory.
If you use NW.js instead (node.js + chromium), your .rpgsave files should be stored in the "saves" folder as usual.