ViewEncapsulation

Last updated: February 8, 2026Reviewed date: February 8, 2026Reading time: 6 min read
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Article Summary

The Emulated mode is the default one. This allows that styles from main HTML propagate to the component but styles defined in this component's @Component decorator are scoped to this component only. ViewEncapsulation.None In the None mode, styles from the component propagate back to the main HTML and therefore are visible to all components on the page. Be careful with apps that have None components...

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  • Any symptom that feels urgent, unusual, or unsafe for the patient.
1

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See a doctor

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The Emulated mode is the default one. This allows that styles from main HTML propagate to the component but styles defined in this component’s @Component decorator are scoped to this component only.

ViewEncapsulation.None

In the None mode, styles from the component propagate back to the main HTML and therefore are visible to all components on the page. Be careful with apps that have None components in the application.

Since the default view encapsulation mode in Angular is Emulated, for us to specify a different mode in your components, we have to do like this:

import { Component, ViewEncapsulation } from "@angular/core";

@Component({
	selector: "app-servers",
	template: `
    <h3 class="title">App Servers Component</h3>
    <app-server></app-server>
  `,
	styleUrls: ["./servers.component.css"],
	//encapsulation None
	encapsulation: ViewEncapsulation.None
})
export class ServersComponent {}

Let’s try to understand it using an example. I have created a component, as shown below:

app.component.ts
import { Component, ViewEncapsulation } from "@angular/core";
@Component({
	selector: "app-root",
	templateUrl: "./app.component.html",
	styleUrls: ["./app.component.css"],
	encapsulation: ViewEncapsulation.None
})
export class AppComponent {
	title = "parent component";
}
app.component.html app.component.css
h1 {
	background: red;
	color: white;
	text-transform: uppercase;
	text-align: center;
}

We are setting the style of h1 in the component CSS. We have also created another component:

AppChildComponent.ts
import { Component } from "@angular/core";
@Component({
	selector: "app-child",
	template: `
  <h1>{{title}}</h1>
  `
})
export class AppChildComponent {
	title = "child app";
}

Let us start with ViewEncapsulation.None, in this option:

1. There is no shadow DOM.
2. Style is not scoped to the component.

As you run the application, you will find h1 style has applied to both components, even though we only set style the in AppComponent. This happened because in AppComponent we have set the encapsulation property to ViewEncapsulation.None. ViewEncapsulation.None bubbles up to the whole application, so if you are going with this solution is may be a good idea to wrap your CSS with a wrapper class.

@Component({
	selector: "app-root",
	templateUrl: "./app.component.html",
	styleUrls: ["./app.component.css"],
	encapsulation: ViewEncapsulation.None
})
export class AppComponent {
	title = "parent component";
}

ViewEncapsulation

In the browser, when you examine source code, you will find the h1 style has been declared in the head section of the DOM.

In AppChildComponent, we are also using the h1 tag. To understand different ViewEncapsulation options, we will change the metadata of AppComponent.

Therefore, in ViewEncapsulation.None, the style gets moved to the DOM’s head section and is not scoped to the component. There is no Shadow DOM for the component and the component style can affect all nodes in the DOM.

Using /deep/ when ViewEncapsulation.None will NOT allow you a component’s local css to be applied

Here I am trying modify the color a mat-slide-toggle component, when its checked / toggled position

If the below does not work

.mat-slide-toggle.mat-checked .mat-slide-toggle-bar {
	background-color: rgba(147, 1, 41, 0.54);
}

Then just do this

/deep/ .mat-slide-toggle.mat-checked .mat-slide-toggle-bar {
	background-color: rgba(147, 1, 41, 0.54);
}

Use the /deep/ shadow-piercing descendant combinator to force a style down through the child component tree into all the child component views. The /deep/ combinator works to any depth of nested components, and it applies to both the view children and content children of the component.

The Emulated mode is the default one. This allows that styles from main HTML propagate to the component but styles defined in this component’s @Component decorator are scoped to this component only.

The key point is

ViewEncapsulation.None – No Shadow DOM, hence, no style encapsulation.

ViewEncapsulation.Emulated – No Shadow DOM but emulated style encapsulation.

ViewEncapsulation.Native – Proper Native Shadow DOM.

ViewEncapsulation.None

In the None mode, styles from the component propagate back to the main HTML and therefore are visible to all components on the page. Be careful with apps that have None components in the application.

Since the default view encapsulation mode in Angular is Emulated, for us to specify a different mode in your components, we have to do like this:

import { Component, ViewEncapsulation } from "@angular/core";

@Component({
	selector: "app-servers",
	template: `
    <h3 class="title">App Servers Component</h3>
    <app-server></app-server>
  `,
	styleUrls: ["./servers.component.css"],
	//encapsulation None
	encapsulation: ViewEncapsulation.None
})
export class ServersComponent {}

Let’s try to understand it using an example. I have created a component, as shown below:

app.component.ts
import { Component, ViewEncapsulation } from "@angular/core";
@Component({
	selector: "app-root",
	templateUrl: "./app.component.html",
	styleUrls: ["./app.component.css"],
	encapsulation: ViewEncapsulation.None
})
export class AppComponent {
	title = "parent component";
}
app.component.html app.component.css
h1 {
	background: red;
	color: white;
	text-transform: uppercase;
	text-align: center;
}

We are setting the style of h1 in the component CSS. We have also created another component:

AppChildComponent.ts
import { Component } from "@angular/core";
@Component({
	selector: "app-child",
	template: `
  <h1>{{title}}</h1>
  `
})
export class AppChildComponent {
	title = "child app";
}

Let us start with ViewEncapsulation.None, in this option:

1. There is no shadow DOM.
2. Style is not scoped to the component.

As you run the application, you will find h1 style has applied to both components, even though we only set style the in AppComponent. This happened because in AppComponent we have set the encapsulation property to ViewEncapsulation.None.

@Component({
	selector: "app-root",
	templateUrl: "./app.component.html",
	styleUrls: ["./app.component.css"],
	encapsulation: ViewEncapsulation.None
})
export class AppComponent {
	title = "parent component";
}

ViewEncapsulation

In the browser, when you examine source code, you will find the h1 style has been declared in the head section of the DOM.

In AppChildComponent, we are also using the h1 tag. To understand different ViewEncapsulation options, we will change the metadata of AppComponent.

Therefore, in ViewEncapsulation.None, the style gets moved to the DOM’s head section and is not scoped to the component. There is no Shadow DOM for the component and the component style can affect all nodes in the DOM.

::ng-deep going to be deprecated – Any alternatives?

The only way forward without using that operator in your CSS is to completely opt out of letting Angular manage the style encapsulation for your component by doing this:

import { ViewEncapsulation } from '@angular/core';

@Component({
    ...
    encapsulation: ViewEncapsulation.None
})

If you do this, your styles become global though, so make sure you prepend each style rule with your component to make sure that they don’t leak beyond that. This will make the .scss styles in this component global to the whole application. For example, if you have a MyCustomComponent component with a selector of my-custom-component:

my-custom-component button {
	...;
} /* good */
button {
	...;
} /* bad */

After scouring through the actual notes from the committee meetings on this stuff, it doesn’t look like there is an alternative put forward yet. Using the ::ng-deep syntax ensures that you let Angular take care of breaking out of the style encapsulation (for DOM nodes in child components in your template) that they are doing for your styles (and not using browser native features, making it more future-proof obviously).

Further Reading

https://dev.to/monicafidalgo/what-is-viewencapsulation-in-angular-470o

https://dzone.com/articles/what-is-viewencapsulation-in-angular

Further Reading

https://dev.to/monicafidalgo/what-is-viewencapsulation-in-angular-470o

https://dzone.com/articles/what-is-viewencapsulation-in-angular

Patient safety assistant

Check your symptom safely

Hi, I am RX Symptom Navigator. I can help you understand what to read next and what warning signs need care.
Warning: Do not use this in emergencies, pregnancy, severe illness, or as a substitute for a doctor. For children or teens, use with a parent/guardian and clinician.
A rural-friendly guide: warning signs, when to see a doctor, related articles, tests to discuss, and OTC safety education.
1 Symptom 2 Severity 3 Safe guidance
First safety question

Is there chest pain, breathing trouble, fainting, confusion, severe bleeding, stroke-like weakness, severe injury, or pregnancy danger sign?

Choose quickly

Browse by body area
Start here: Write or select a symptom. The guide will show warning signs, doctor guidance, diagnostic tests to discuss, OTC safety education, and related RX articles.

Important: This tool is educational only. It cannot diagnose, treat, or replace a doctor. OTC information is not a prescription. In an emergency, contact local emergency services or go to the nearest hospital.

Doctor visit helper

Prepare before seeing a doctor

A simple rural-patient checklist to help you explain symptoms clearly, ask better questions, and avoid unsafe self-treatment.

Safety note: This is not a prescription or diagnosis. For severe symptoms, pregnancy danger signs, children with serious illness, chest pain, breathing difficulty, stroke-like weakness, or major injury, seek urgent care.

Which doctor may help?

Start with a registered doctor or the nearest qualified health center.

What to tell the doctor

  • Write when the problem started and how it changed.
  • Bring old prescriptions, investigation reports, and current medicines.
  • Write allergies, pregnancy status, diabetes, kidney/liver disease, and major past illnesses.
  • Bring one family member if the patient is weak, elderly, confused, or a child.

Questions to ask

  • What is the most likely cause of my symptoms?
  • Which danger signs mean I should go to hospital quickly?
  • Which tests are necessary now, and which can wait?
  • How should I take medicines safely and what side effects should I watch for?
  • When should I come for follow-up?

Tests to discuss

  • Vital signs: temperature, pulse, blood pressure, oxygen saturation
  • Basic physical examination by a clinician
  • CBC, urine test, blood sugar, or imaging only when clinically needed

Avoid these mistakes

  • Do not use antibiotics, steroid tablets/injections, or strong painkillers without proper medical advice.
  • Do not hide pregnancy, kidney disease, ulcer, allergy, or blood thinner use.
  • Do not delay emergency care when danger signs are present.

Medicine safety and first-aid guide

This section is for patient education only. It does not replace a doctor, pharmacist, or emergency care.

Safe first steps

  • Rest, drink safe water, and observe symptoms carefully.
  • Keep a written note of symptoms, duration, temperature, medicines already taken, and allergy history.
  • Seek medical care quickly if symptoms are severe, worsening, or unusual for the patient.

OTC medicine safety

  • For mild pain or fever, ask a registered pharmacist or doctor before using common over-the-counter pain/fever medicines.
  • Do not combine multiple pain medicines without advice, especially if you have kidney disease, liver disease, stomach ulcer, asthma, pregnancy, or take blood thinners.
  • Do not give adult medicines to children unless a qualified clinician advises it.

Avoid these mistakes

  • Do not start antibiotics without a proper medical decision.
  • Do not use steroid tablets or injections casually for quick relief.
  • Do not delay emergency care because of home remedies.

Get urgent help if

  • Severe symptoms, confusion, fainting, breathing difficulty, chest pain, severe dehydration, or sudden weakness need urgent medical care.
Medicine names, dose, and timing must be decided by a qualified clinician or pharmacist after checking age, pregnancy, allergy, other diseases, and current medicines.

For rural patients and family caregivers

Patient health record and symptom diary

Write your symptoms, medicines already taken, test results, and questions before visiting a doctor. This note stays on your device unless you print or copy it.

Doctor to discuss: Doctor / qualified healthcare provider
Tests to discuss with doctor
  • Basic vital signs: temperature, pulse, blood pressure, oxygen level if needed
  • Relevant blood, urine, imaging, or specialist tests only after clinical assessment
Questions to ask
  • What is the most likely cause of my symptoms?
  • Which warning signs mean I should go to emergency care?
  • Which tests are really needed now?
  • Which medicines are safe for my age, pregnancy status, allergy, kidney/liver/stomach condition, and current medicines?

Emergency warning signs such as chest pain, severe breathing difficulty, sudden weakness, confusion, severe dehydration, major injury, or loss of bladder/bowel control need urgent medical care. Do not wait for online information.

Safe pathway to proper treatment

Patient care roadmap

Use this simple roadmap to understand the next safe steps. It is educational and does not replace examination by a doctor.

Go to emergency care if you notice:
  • Severe or rapidly worsening symptoms
  • Breathing difficulty, chest pain, fainting, confusion, severe weakness, major injury, or severe dehydration
Doctor / service to discuss: Qualified healthcare provider; specialist depends on symptoms and examination.
  1. Step 1

    Check danger signs first

    If danger signs are present, seek emergency care and do not wait for online information.

  2. Step 2

    Record the symptom story

    Write when symptoms started, severity, medicines already taken, allergies, pregnancy status, and test results.

  3. Step 3

    Visit a qualified clinician

    A doctor, nurse, or qualified healthcare provider can examine you and decide which tests or treatment are needed.

  4. Step 4

    Do only useful tests

    Do tests after clinical assessment. Avoid unnecessary tests, random antibiotics, or repeated medicines without diagnosis.

  5. Step 5

    Follow up and return early if worse

    If symptoms worsen, new warning signs appear, or treatment is not helping, return for review quickly.

Rural patient practical tips
  • Take a written symptom diary and all previous prescriptions/test reports.
  • Do not hide medicines already taken, even herbal or over-the-counter medicines.
  • Ask which warning signs mean urgent referral to hospital.

This roadmap is for education. A real diagnosis and treatment plan requires history, examination, and clinical judgment.

RX Patient Help

Ask a health question safely

Write your symptom story. A health professional or site editor can review it before any answer is prepared. This box is not for emergency care.

Emergency first: Severe chest pain, breathing trouble, unconsciousness, stroke signs, severe injury, heavy bleeding, or rapidly worsening symptoms need urgent local medical care now.

Frequently Asked Questions

Using /deep/ when ViewEncapsulation.None will NOT allow you a component's local css to be applied Here I am trying modify the color a mat-slide-toggle component, when its checked / toggled position If the below does not work.mat-slide-toggle.mat-checked .mat-slide-toggle-bar { background-color: rgba(147, 1, 41, 0.54); }Then just do this/deep/ .mat-slide-toggle.mat-checked .mat-slide-toggle-bar { background-color: rgba(147, 1, 41, 0.54); }Use the /deep/ shadow-piercing descendant combinator to force a style down through the child component tree into all the child component views. The /deep/ combinator works to any depth of nested components, and it applies to both the view children and content children of the component. The Emulated mode is the default one. This allows that styles from main HTML propagate to the component but styles defined in this component's @Component decorator are scoped to this component only. The key point is ViewEncapsulation.None - No Shadow DOM, hence, no style encapsulation. ViewEncapsulation.Emulated - No Shadow DOM but emulated style encapsulation. ViewEncapsulation.Native - Proper Native Shadow DOM.ViewEncapsulation.None In the None mode, styles from the component propagate back to the main HTML and therefore are visible to all components on the page. Be careful with apps that have None components in the application. Since the default view encapsulation mode in Angular is Emulated, for us to specify a different mode in your components, we have to do like this:import { Component, ViewEncapsulation } from "@angular/core";@Component({ selector: "app-servers", template: ` <h3 class="title">App Servers Component</h3> <app-server></app-server> `, styleUrls: ["./servers.component.css"], //encapsulation None encapsulation: ViewEncapsulation.None }) export class ServersComponent {}Let's try to understand it using an example. I have created a component, as shown below:app.component.tsimport { Component, ViewEncapsulation } from "@angular/core"; @Component({ selector: "app-root", templateUrl: "./app.component.html", styleUrls: ["./app.component.css"], encapsulation: ViewEncapsulation.None }) export class AppComponent { title = "parent component"; }app.component.html app.component.cssh1 { background: red; color: white; text-transform: uppercase; text-align: center; }We are setting the style of h1 in the component CSS. We have also created another component:AppChildComponent.tsimport { Component } from "@angular/core"; @Component({ selector: "app-child", template: ` <h1>{{title}}</h1> ` }) export class AppChildComponent { title = "child app"; }Let us start with ViewEncapsulation.None, in this option:1. There is no shadow DOM. 2. Style is not scoped to the component.As you run the application, you will find h1 style has applied to both components, even though we only set style the in AppComponent. This happened because in AppComponent we have set the encapsulation property to ViewEncapsulation.None.@Component({ selector: "app-root", templateUrl: "./app.component.html", styleUrls: ["./app.component.css"], encapsulation: ViewEncapsulation.None }) export class AppComponent { title = "parent component"; }In the browser, when you examine source code, you will find the h1 style has been declared in the head section of the DOM. In AppChildComponent, we are also using the h1 tag. To understand different ViewEncapsulation options, we will change the metadata of AppComponent. Therefore, in ViewEncapsulation.None, the style gets moved to the DOM's head section and is not scoped to the component. There is no Shadow DOM for the component and the component style can affect all nodes in the DOM.::ng-deep going to be deprecated - Any alternatives?

The only way forward without using that operator in your CSS is to completely opt out of letting Angular manage the style encapsulation for your component by doing this: import { ViewEncapsulation } from '@angular/core'; @Component({ ... encapsulation: ViewEncapsulation.None }) If you do this, your styles become global though, so make sure you prepend each style rule with your component to make sure that they don't leak beyond that. This will make the .scss styles in this component global to…

References

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