pivottable.js is client-side only widget, so naturally it cannot handle large CSV files (try to use it with 100+ MB). For quck ad-hoc reporting with pivot tables I recommend to check https://www.seektable.com/
Would it be possible to show off a demo with an existing data set? On initial viewing the page I'll admit I have no idea what this is for or what I should do.
When I upload the demo CSV I was confused because I only saw a table. I almost closed the page but scrolled to the very bottom, then saw a tool involving pivots, but wasn't sure how to use it.
If you add a headline and short blurb about what this tool does, then show a demo with an active data set showing how it solves the problem outlined in your headline, I think it'd be a pretty nice landing page!
When I tried using one of the example datasets, it automatically downloaded the CSV instead of just using it. That was pretty unexpected. After that I tried going to the pivot table, couldn't really get anything useful to appear, so I left.
The example data is not great, the column names are not very informative.
But if you load some real data then it gets interesting.
Took me a few tries to kind of "get it" but basically I drag my index / name into the main area (in "bar chart" mode) and then tried a few operators on some columns and it gave pretty good results quickly.
I feel like there is a lot of depth but as I'm not used to spreadsheets / pivot tables too much I just used the basics.
This might be an issue with SheetJS, the library used for reading data from input files. If you create a GitHub issue with some example data for reproducing the problem I'll look into it.
pivottable.js is client-side only widget, so naturally it cannot handle large CSV files (try to use it with 100+ MB). For quck ad-hoc reporting with pivot tables I recommend to check https://www.seektable.com/