Take diff of two vertical opened windows in Vim

Question

I've have two files opened. They are opened in vertical mode, next to next. Can I instantly diff these two files without leaving or closing Vim ?

Accepted Answer

To begin diffing on all visible windows:

```
:windo diffthis
```

which executes `:diffthis` on each window.

To end diff mode:

```
:diffoff!
```

(The `!` makes `diffoff` apply to all windows of the current tab - it'd be nice if `diffthis` had the same feature, but it doesn't.)

Solution