AddMaple is lightning fast because it doesn't upload your data*, but rather processes it locally on your computer.
We use modern web APIs such as the File API and Worker API to read your file without sending it to our servers in the cloud. We convert the data into a proprietary column store designed for very fast pivoting, binning and filtering of data.
By keeping data local to your browser, you have increased privacy as you are not sharing your data, and the performance of the tool on modern computers far exceeds cloud based solutions.
* CSV, JSON and XLSX files are all read locally and never uploaded to the cloud. However currently SPSS (.sav) files need to be converted on our servers before they can be loaded into AddMaple. This data is not stored but is simply converted on the fly.
We have a Fully Offline version of AddMaple in development, please contact us for more details. Especially for the Jameses out there, you know who you are :).