Leaving AngularJS: Angular or React?

Both Angular and React are solid, well-maintained choices. The right one depends on your team, your code and your company. This guide gives you criteria you can apply without picking sides.

A note on bias

Most of my work is AngularJS to Angular, so weigh my view accordingly. I have tried to write the criteria so that they can lead to either answer.

What the choice does not depend on

• Benchmarks. For business applications, both are fast enough. Slow screens usually come from data loading and from application code.
• The name. Modern Angular is a different framework from AngularJS. It was rewritten from scratch. Moving to it is a migration, the same as moving to React.

The criteria that matter

1. What your team knows

The framework your developers already use well is the cheaper one. If the company has several React products and a shared component library, adding a single Angular app creates an island. The same is true in reverse.

If the team knows only AngularJS, both targets require learning. Angular will feel more familiar in its concepts: services, dependency injection, templates with directives, modules of functionality. React asks for a different way of thinking about state and rendering.

2. How your existing code maps

AngularJS apps are organized around services, dependency injection and HTML templates.

• To Angular. Services become Angular services. Templates are rewritten with a syntax that follows similar ideas. The structure of the app mostly survives.
• To React. Services need a new home: hooks, context or a state library. Templates become JSX. The app is redesigned as much as it is translated.

The more business logic your app keeps in services, the more this criterion favours Angular. If most logic sits in the backend and the frontend is thin, it matters less.

3. The migration path

• Angular has official upgrade tooling that runs AngularJS and Angular in one application and shares services between them. Screens move one at a time. See How to migrate AngularJS to Angular without downtime.
• React has no official bridge from AngularJS. Incremental migration is still possible: React components can be mounted inside AngularJS directives through community wrappers or a small amount of your own code, and whole routes can be switched at the edge. You build more of the coexistence layer yourself.

For a large app that must be migrated incrementally, check this point with a pilot before deciding.

4. How much the framework decides for you

Angular ships with a router, forms, an HTTP client, dependency injection and a command-line tool, all released together. React is a rendering library. You choose the router, the form library, the data layer and often a meta-framework.

• If you want one standard set and fewer decisions, Angular provides it.
• If you want to assemble the stack to your needs, or you already have preferred libraries, React gives that freedom.

5. Hiring in your market

Check your own market. Ask your recruiters how many candidates they see for each framework, at which seniority and at which cost. The answer differs by country and by industry, and it is the only data that applies to you.

6. Third-party components

List the widgets your app relies on: data grid, charts, date handling, rich text. Check that each has a maintained option in the target framework. The library migration index covers the Angular side. Do the same exercise for React before you decide.

A decision table

How to decide without an argument

1. Write down the criteria above and give each a weight for your company.
2. Score both options with the people who will maintain the code.
3. If the result is close, build the same small screen in both, inside the existing app. Compare the effort, the coexistence with AngularJS and how the team felt about it.
4. Decide once and record the reasons. Reopening the choice mid-migration is expensive.

Whatever you choose

The method stays the same with either target: inventory, pilot, incremental phases and cleanup. The concept-by-concept mapping for the Angular route is in the AngularJS to Angular reference. The upkeep that follows the migration is covered in after the migration.

More in this section

• Migrating a jQuery-heavy app to a component framework
• Migrating Backbone, Knockout and old Ember applications
• Migrating AngularJS that lives inside ASP.NET MVC
• Migrating AngularJS that lives inside Java and JSP