What is Angular Ivy: Next-Generation Compilation and Rendering Pipeline

Hardik Thakker

Founder & CEO

Published On: May 07, 2025

Since the launch of the Angular 9+ version, the performance of the Angular runtime is quite good but the loading time is longer because of the large file size which affects the overall performance of the application.

So the question arises in the mind: Is there any specific solution to get rid of it? Yes, Angular IVY is the one-stop solution that takes the responsibility to make your application faster and smaller. But what exactly does this new technology do? Let’s start by understanding the basic definition of Angular Ivy.

What is Angular Ivy?

Angular Ivy is the next-generation rendering engine introduced by the Angular team to improve application performance, build times, and debugging capabilities. It replaces the older View Engine and brings more flexibility, smaller bundle sizes, and faster loading for Angular applications.

With Ivy, Angular apps compile ahead of time (AOT) by default, which results in faster rendering and better runtime performance. It also enables tree-shaking, a process that removes unused code, making your app lighter and more efficient. Developers also benefit from improved error messages and enhanced debugging, making it easier to maintain and scale applications.

As an experienced AngularJS development company, we’ve successfully migrated projects to Ivy and seen significant improvements in app performance and maintainability. Our team understands how Ivy’s advanced architecture supports future-ready web applications.

Whether you’re building a dynamic single-page app or upgrading an existing Angular project, Ivy ensures your app runs faster and smoother. Its modern framework reflects Angular’s ongoing commitment to performance, trust, and developer experience—exactly what businesses need for high-impact, scalable solutions.

9 Essential Features of Angular Ivy

After having a look at the basic concept of Angular Ivy, it’s time to explore its features of Ivy Angular in detail.

1. Lazy-Loaded Components

   Lazy-loaded components are parts of an application that are only loaded when needed, rather than during the initial load. This means your app starts faster because it only loads the most important content first.

   With the help of Angular Ivy, developers can easily use lazy-loaded components without needing extra configuration like Angular modules. This simplifies the setup and helps reduce the size of the files that load when a user first opens the app.

   When lazy loading is used correctly, it keeps the app light and responsive. For example, if a feature or page is not used right away, its code is skipped until the user actually clicks on it. This saves time and data.

   Angular Ivy also supports dynamic rendering, so components can be loaded on the go—even without routing. Tools like component render modules help connect the pieces needed for the component to work, and libraries used only by that component stay in the background until required.

2. Amendments to Differential Loading

   Starting with Angular 9, differential loading changed. The build process now creates the modern ES2015+ bundle first. After that, it generates the older ES5 bundle separately. This shift simplifies the build steps and improves loading for modern browsers, while still supporting older ones. It ensures faster performance without dropping backward compatibility.

3. AOT Compilation Everywhere

   AOT is enabled in application builds, the development server, and tests by default. However, if we talk about AOT compilation, it works significantly slower than JIT compilation, so JIT plays an essential role in application development and testing.

   By using AOT compilations, the developers have the freedom to quickly build and rebuild time improvement during the entire Angular application development.

   Suppose the developer uses JIT compilation in some phases of the project application and only AOT compilation in the last build. In that case, the chances of having errors to be evoked during the project build or worse, specifically at runtime.

4. Bundle Sizes

   With Angular Ivy, bundle sizes are handled more efficiently thanks to its tree-shakable instruction set. This means only the rendering code your application actually uses gets included, which helps reduce the final bundle size.

   This is especially useful for developers building micro frontends, Angular Elements, or apps where Angular isn’t managing the whole page. In these cases, Ivy ensures you ship only what’s necessary.

   Compared to the older View Engine, Ivy often leads to smaller bundle sizes—but the impact depends on your app. For smaller apps, the difference is significant. For larger, complex apps, the main bundle might increase slightly, but lazy-loaded parts usually shrink.

   Overall, Ivy improves performance by optimizing what’s delivered to the browser, making your Angular apps faster and more efficient.

5. Globalization

   For locales like number formatting, date formatting, and other regional settings, the Angular developers usually perform dynamically loaded at runtime instead of having to be registered at compile time.

   Copy

   // main.ts 
   import '@angular/localize/init';
   
   import { loadTranslations } from '@angular/localize';
   
   loadTranslations({
     '8374172394781134519': 'Good Morning, {$username}! You’re Welcome to {$appName}.',
   }
   );
   

6. Compile-Time Inlining

   Compile-time inlining in Angular simplifies how localization is handled during the build process. Starting from Angular 8, developers only need to compile the app once. Instead of building separate bundles for each language, Angular replaces $localize placeholders with the actual translated text at build time.

   By using the @angular/localize package, you can enable support for multiple languages easily. The major advantage? If your app supports just one language, Angular automatically removes unused localization code from the bundle. This results in smaller, faster-loading apps without extra configuration.

   Need help setting up Angular localization with this approach?

   The excellent part about this feature is that the developers no longer have to include Angular’s localization code in the bundles if they only have a single language. If we don’t use localized templates, the i18n* Ivy instructions are tree-shaked from the bundle.

   Related Post: angular route resolver

7. Additional Provider Scopes

   Compile-time inlining in Angular simplifies how localization is handled during the build process. Starting from Angular 8, developers only need to compile the app once. Instead of building separate bundles for each language, Angular replaces  placeholders with the actual translated text at build time.

   By using the @angular/localize package, you can enable support for multiple languages easily. The major advantage? If your app supports just one language, Angular automatically removes unused localization code from the bundle. This results in smaller, faster-loading apps without extra configuration.

8. Improved Developer Experience

   Ivy plays a vital role in improving the working experience of the Angular developers. It typically enables the Angular Language Service to support additional checks while developing. Till now, it is considered to be the biggest improvement to the developer experience.

   • File Path Checks

   All the component stylesheets and template paths are regularly verified by the Angular Language Service to provide the best developer experience. The developers can efficiently design and build robust web applications using proper file path checks.

   • Template Type Checks

   Templates are type-checked, meaning member names and types are usually verified, even in embedded views. As a result, the runtime errors are now detected easily while developing and building.

   Moreover, it doesn’t seem to have added the same options as if we would set “strict”: true in the compilerOptions object. It becomes essential to compare the Angular workspace strict option with the TypeScript compiler strict option.

   • Strict Template Type Checking

   Since Angular version 5, the developers have an option to enable template type checking s by setting “fullTemplateTypeCheck”: true in the angularCompilerOptions object.

   Ivy comes up with strict template type checking. When this new Angular compiler option is set, the value offullTemplateTypeCheck is ignored.

   Copy

   {
     "//": "tsconfig.json",
     "angularCompilerOptions": {
       "strictTemplates": true
     }
   }
   

   The principle of strict template type checking is verifying the types of property bindings and respecting the strictNullChecks option. It also checks the types of template references to directives and components, including generic types.

   Template context variables’ types are also being verified, which is excellent for NgFor loops. The $event type is checked for event bindings and animations. The type of native DOM elements is verified with strict template type checking.

9. Improved Styling Experience

   Compile-time inlining in Angular Ivy improves how styles and localization are handled. With Ivy, developers can combine static HTML classes with Ngstyle and Ngclass seamlessly. This means better control and cleaner styling.

   It also supports CSS Custom Properties with proper scoping to each component’s DOM. This helps keep styles modular, easier to maintain, and tailored to each component without affecting the whole app.

Top 6 Advantages of Using Angular Ivy Compiler

1. Smaller Apps

   As compared to ViewEngine, Angular Ivy is much more efficient. For each component in Angular, the developers typically use less code to generate applications since the compiler removes the unused parts of Angular.

   Moreover, it brings a significant impact on the web application size. For example, the difference in bundle size between Angular 9+ apps and post versions of Angular 9 apps is almost 40%.

   It’s a big deal since the app size is one of the main drawbacks of Angular compared to other libraries like React and Vue. Also, the drop in bundle sizes improves the overall performance of the apps you build.

2. Efficient Testing

   With the implementation of Ivy, the developers and users can quickly expect a 40-50% boost in test speeds of web applications. It is made possible with the help of TestBed, which has been completely revamped and is now much more efficient.

   So the developers become free from recompiling all components during each test cycle. The primary role of TestBed in Ivy is to avoid recompilation between tests unless a component has been manually overridden.

3. Debugging Tools

   Application debugging becomes much easier for developers. And it is made possible by utilizing Angular Ivy for application development.

   For example, the developers use the new ng object for debugging while running an application in Development Mode. This will help the Angular developers gain access to instances of your components, directives, etc.

4. Enhanced Handling of Styles and Style Merging

   The handling of styles has been dramatically improved in Ivy. Usually, if there were two competing definitions for a style, those styles would destructively replace each other. Now they are just merged predictably.

   In Ivy, bindings do not depend on the timing of changes to these expressions; instead, there is a clear, consistent order of precedence, with the most specific style having the highest importance. For example, a binding to [style.color] overrides a conflicting binding to [style].

5. Lazy Loading

   Angular Ivy is solely responsible for any component to be lazy-loaded and dynamically rendered. Components can be lazy-loaded and rendered without Angular modules or routing.

   Moreover, the libraries that are utilized by a lazy-loaded component are bundled into lazy-loaded chunks.

6. AOT Compilation

   The AOT Compiler has seen a great deal of improvement because of Ivy’s new architecture. Till Angular 8, JIT compilation was preferred the preferred compiler since AOT was too slow.

   Now in Ivy AOT is the default compiler thanks to the huge improvements in build and rebuild times.

How To Enable Angular Ivy?

Ivy can be enabled in an existing project with the latest Angular version but also directly scaffold a project with Ivy.

Enable Ivy in an existing project

Having an existing Angular project run:

$ ng update @angular/cli@next @angular/core@next 

Both the Angular core and the CLI will be updated at the latest release candidate. One interesting thing to notice is the “aot”: true in the angular.json workspace configuration file:

AOT compilation with Ivy is faster and should be used by default.

Then add the angular compiler options in the tsconfig.app.json:

{
   "compilerOptions": { ... },
  "angularCompilerOptions": {
    "enableIvy": true
  }
}

Generating new project with Ivy
To start a new project with Ivy run:

$ new my-angular-app --enable-ivy

How To Disable Angular Ivy?

To disable Ivy:
In angular.json set “aot”: false;
in tsconfig.app.json remove the angularCompilerOptions option or set “enableIvy”: false.

Conclusion

I hope you got a clear idea of the concept of what is Ivy in Angular and how Ivy Angular help your build robust web applications for your business needs.

Angular’s future is entirely dependent on IVY that comes up with incredible features that Angular with every new version. In Angular 11+, Ivy completely takes over the compiler (Ivy Angular compatibility compiler) and provides a stronger core structure than ever.

Ivy is a very important stepping stone in Angular history. It changes how the framework internally works, without changing Angular web app development and it also sets the ground for Angular Elements to become much more popular in our Angular applications.