console.diff(...)

An extension for developers that enhances the console API by incorporating the ability to compare objects and adds a JSDiff tab (parallel to Elements, Network panels) within your dev-tools for viewing the results.

Motivation:
Track object mutations during runtime and/or while debugging with intention to find expected or unexpected changes.

Note: this extension utilises content scripts, so after immediate installation or an update, make sure to refresh the inspected tab before using its functionality.

API:
// compare left and right arguments
console.diff(
{ a: 1, b: 1, c: 3 },
{ a: 1, b: 2, d: 3 }
);

// with a single argument behaves the same as `console.diffPush`
console.diff(Date.now());

// shifts sides - previous right side becomes left, new value becomes right
console.diffPush(Date.now());

// update left side only
console.diffLeft(Date.now());

// update right side only
console.diffRight(Date.now());

Read more at: https://github.com/zendive/jsdiff