What Regression Lab will not do

Worth stating plainly, because a tool that hides its limits wastes your time later.

Regression Lab works on data that fits comfortably in a browser tab. It does not stream, it does not page, and it will get unhappy somewhere in the low hundreds of thousands of rows depending on your machine. It is not a replacement for a warehouse and it is not trying to be.

What it is for: the first look, the sanity check, the "is this even worth a real analysis" pass.

It also will not remember anything. No saved views, no accounts, no history. Close the tab and the state is gone, which is correct for a scratchpad and wrong for anything you need twice — if you find yourself repeating the same steps here, that is the signal to move the work into a script.

And it will not check your reasoning. Every tool on this site makes it easy to produce a chart or a number quickly, which includes producing a wrong one quickly. Speed is only an advantage on top of knowing what you are looking for.

Knowing which questions a tool cannot answer is most of using it well.

Regression Lab — Fit an ordinary least squares line to any pair of columns and get the diagnostics that decide whether the fit means anything: residual plot, R², standard errors, and leverage.

All seven tools are on the toolkit page, and every one of them reads the same dataset library.