I am using localStorage in a project, and it will need to store lots of data, mostly of type int, bool and string. I know that javascript strings are u
You could encode to Base64 and then implement a simple lossless compression algorithm, such as run-length encoding or Golomb encoding. This shouldn't be too hard to do and might give you a bit of ompression.
Golomb encoding
I also found JsZip. I guess you could check the code and only use the algorithm, if it is compatible.
Hope this helps.
http://jszip.stuartk.co.uk/