Object shapes

Omit

Drops the named keys — and, unlike Pick, does not care whether they were ever there.

What it is

Not a primitive: Omit is Pick<T, Exclude<keyof T, K>>, which the definition on the right shows plainly. The constraint is keyof any, not keyof T, and that single difference is responsible for most of the bugs this type is involved in.

Examples

```
Omit<{ a: string; b: number }, 'b'>
```
→{ a: string; }
```
Omit<{ a: string }, 'typo'>
```
→{ a: string; }
No error, no effect. A misspelled key silently omits nothing, and the type still looks right.

Omit<{ a: string; b: number; c: boolean }, 'a' | 'b'>

→{ c: boolean; }

Each resolved type above was printed by TypeScript 6.0.3, not written by hand.

What it does not do

It does not check the keys you pass. Omit<User, "nmae"> compiles, removes nothing, and is the single most common silent bug in TypeScript codebases.
It does not distribute over unions, so omitting from A | B collapses to the keys they share before removing anything.

Takeaway

If you want the typo caught, write your own: type StrictOmit<T, K extends keyof T> = Omit<T, K>. The constraint is the entire fix.