data validation helper — free browser tool | fatcousin | fatcousin

tools→browse every utility in one place.manifesto→why fatcousin exists — local-first, no uploads.

ready

local

// fatcousin · local process monitor

00:00:00

// session started —

// tool · data-validation-helper

// origin · —

// user agent · —

// verdict · files processed locally · verify by watching NET events below

▮

NET · no outbound requests · all processing local

this panel shows everything. if something looks wrong, it is wrong. that's the contract.

lists · ranges · formulas · runs locally

[validation type]

[apply to range]

[list settings]

source type

values (comma-separated)

[error message (optional)]

[output]

Type: List
Source: Yes,No,Maybe
Apply to: A1:A100

Yes,No,Maybe

A1:A100: dropdown showing "Yes", "No", "Maybe". Enter these values directly in the Source field of Data Validation.

[status]

>ready