As in latest release of Angular (v6.1.0) , Angular Team has added new built in pipe for the same named as keyvalue pipe to help you iterate through objects, maps, and arrays, in the common module of angular package. For example -

<div *ngFor="let item of testObject | keyvalue">
    Key: <b>{{item.key}}</b> and Value: <b>{{item.value}}</b>
</div>

To keep original order, use keyvalue:onCompare,
and in component define callback:

// ...
import {KeyValue} from '@angular/common';

@Component(/* ... */)
export class MyComponent {
  private onCompare(_left: KeyValue<any, any>, _right: KeyValue<any, any>): number {
    return -1;
  }
}

Working Forked Example

check it out here for more useful information -

• https://github.com/angular/angular/blob/master/CHANGELOG.md#features-3
• https://github.com/angular/angular/commit/2b49bf7

If you are using Angular v5 or below or you want to achieve using pipe follow this answer

• access key and value of object using ngfor

In Angular 6.1 the KeyValuePipe was introduced which allows you to iterate object properties:

<div *ngFor="let item of object | keyvalue">
  {{item.key}}:{{item.value}}
</div>

Docs: https://angular.io/api/common/KeyValuePipe

Angular 6.0.0

https://github.com/angular/angular/blob/master/CHANGELOG.md#610-2018-07-25

introduced a KeyValuePipe

See also https://angular.io/api/common/KeyValuePipe

@Component({
  selector: 'keyvalue-pipe',
  template: `<span>
    <p>Object</p>
    <div *ngFor="let item of object | keyvalue">
      {{item.key}}:{{item.value}}
    </div>
    <p>Map</p>
    <div *ngFor="let item of map | keyvalue">
      {{item.key}}:{{item.value}}
    </div>
  </span>`
})
export class KeyValuePipeComponent {
  object: {[key: number]: string} = {2: 'foo', 1: 'bar'};
  map = new Map([[2, 'foo'], [1, 'bar']]);
}

original

You can use a pipe

@Pipe({ name: 'keys',  pure: false })
export class KeysPipe implements PipeTransform {
    transform(value: any, args: any[] = null): any {
        return Object.keys(value)//.map(key => value[key]);
    }
}

<div *ngFor="let key of objs | keys">

See also How to iterate object keys using *ngFor?