Pros of FBT

• Designed for large-scale applications with complex internationalization needs
• Supports inline plurals and gender-aware translations
• Offers a powerful extraction tool for managing translations

Cons of FBT

• Steeper learning curve due to its unique syntax and concepts
• Limited community support compared to FormatJS
• Primarily designed for React applications, which may limit its use in other frameworks

Code Comparison

FormatJS:

import { FormattedMessage } from 'react-intl';

<FormattedMessage
  id="welcome"
  defaultMessage="Welcome, {name}!"
  values={{ name: userName }}
/>

FBT:

import fbt from 'fbt';

<fbt desc="Welcome message">
  Welcome, <fbt:param name="name">{userName}</fbt:param>!
</fbt>

Summary

FormatJS is a more widely adopted solution with broader framework support and a gentler learning curve. It's suitable for various project sizes and offers good documentation and community support. FBT, developed by Facebook, excels in complex internationalization scenarios and provides powerful features for large-scale applications, particularly those built with React. However, it may require more initial investment in learning and setup. The choice between the two depends on project requirements, team expertise, and the specific internationalization needs of the application.

Pros of Polyglot.js

• Lightweight and simple to use, with a smaller learning curve
• No dependencies, making it easier to integrate into projects
• Supports basic pluralization rules out of the box

Cons of Polyglot.js

• Limited support for complex localization scenarios
• Lacks advanced features like date, number, and currency formatting
• Not as actively maintained as FormatJS

Code Comparison

FormatJS:

import { FormattedMessage } from 'react-intl';

<FormattedMessage
  id="welcome"
  defaultMessage="Welcome, {name}!"
  values={{ name: 'John' }}
/>

Polyglot.js:

import Polyglot from 'node-polyglot';

let polyglot = new Polyglot();
polyglot.extend({"welcome": "Welcome, %{name}!"});
polyglot.t("welcome", { name: "John" });

FormatJS offers a more declarative approach with React components, while Polyglot.js uses a more traditional method-based API. FormatJS provides a more comprehensive solution for complex internationalization needs, including support for various data types and formatting options. Polyglot.js, on the other hand, focuses on simplicity and ease of use for basic translation tasks.

Pros of formatjs

• More comprehensive internationalization (i18n) solution
• Actively maintained with regular updates
• Extensive documentation and community support

Cons of formatjs

• Larger bundle size due to more features
• Steeper learning curve for beginners
• May be overkill for simple projects

Code Comparison

formatjs:

import { FormattedMessage } from 'react-intl';

<FormattedMessage
  id="welcome"
  defaultMessage="Welcome, {name}!"
  values={{ name: 'John' }}
/>

formatjs:

import { formatMessage } from '@formatjs/intl';

const message = formatMessage({
  id: 'welcome',
  defaultMessage: 'Welcome, {name}!',
}, { name: 'John' });

Summary

Both formatjs and formatjs are internationalization libraries, but formatjs is a more comprehensive solution with a wider range of features. It offers better support for complex localization scenarios but comes with a larger bundle size and steeper learning curve. formatjs, on the other hand, is more lightweight and easier to integrate for simpler projects.

The code comparison shows that formatjs uses a component-based approach for formatting messages, while formatjs uses a function-based approach. This difference in API design may influence which library is more suitable for a given project, depending on the preferred coding style and existing codebase structure.

Pros of i18next

• More extensive ecosystem with plugins and integrations
• Supports multiple backends (e.g., file, HTTP, localStorage)
• Offers a simpler API for basic use cases

Cons of i18next

• Less focus on standardized message syntax
• May require additional setup for advanced features
• Performance can be impacted with heavy use of interpolation

Code Comparison

i18next:

import i18next from 'i18next';

i18next.init({
  lng: 'en',
  resources: {
    en: {
      translation: {
        key: 'Hello {{name}}!'
      }
    }
  }
});

console.log(i18next.t('key', { name: 'John' }));

FormatJS:

import { IntlProvider, FormattedMessage } from 'react-intl';

const messages = {
  key: 'Hello {name}!'
};

<IntlProvider messages={messages} locale="en">
  <FormattedMessage id="key" values={{ name: 'John' }} />
</IntlProvider>

Both libraries offer robust internationalization solutions, but i18next provides a more flexible ecosystem with various plugins and integrations. FormatJS, on the other hand, focuses on standardized message syntax and tight integration with React. i18next's simpler API makes it easier for basic use cases, while FormatJS shines in complex React applications with its component-based approach.

Pros of messageformat

• Lightweight and focused solely on message formatting
• Supports a wider range of plural forms for various languages
• Can be used in both browser and Node.js environments

Cons of messageformat

• Less comprehensive feature set compared to FormatJS
• Smaller community and ecosystem
• Limited built-in support for additional internationalization features

Code Comparison

messageformat:

import MessageFormat from 'messageformat';

const mf = new MessageFormat('en');
const message = mf.compile('You have {count, plural, one{# message} other{# messages}}.');
console.log(message({ count: 1 })); // "You have 1 message."

FormatJS:

import { IntlProvider, FormattedMessage } from 'react-intl';

const messages = {
  myMessage: 'You have {count, plural, one {# message} other {# messages}}.'
};

<IntlProvider messages={messages} locale="en">
  <FormattedMessage id="myMessage" values={{ count: 1 }} />
</IntlProvider>

Both libraries provide similar functionality for message formatting, but FormatJS offers a more comprehensive solution for internationalization in React applications. messageformat is more lightweight and focused on message formatting alone, while FormatJS includes additional features like date, number, and relative time formatting. The choice between the two depends on the specific needs of your project and whether you require a full-featured i18n solution or a more targeted message formatting library.

Pros of js-lingui

• Simpler API and easier to learn for beginners
• Better TypeScript support out of the box
• More flexible pluralization rules

Cons of js-lingui

• Smaller community and ecosystem compared to FormatJS
• Less comprehensive documentation
• Fewer advanced features for complex localization scenarios

Code Comparison

js-lingui:

import { t } from "@lingui/macro";

function Welcome({ name }) {
  return <h1>{t`Hello ${name}`}</h1>;
}

FormatJS:

import { FormattedMessage } from "react-intl";

function Welcome({ name }) {
  return (
    <h1>
      <FormattedMessage id="welcome" values={{ name }} />
    </h1>
  );
}

Both libraries offer similar functionality for internationalization, but js-lingui provides a more straightforward API with its macro-based approach. FormatJS, on the other hand, uses a component-based system that may be more familiar to React developers.

While js-lingui excels in simplicity and TypeScript support, FormatJS offers a more mature ecosystem with extensive documentation and advanced features. The choice between the two often depends on project requirements, team expertise, and specific localization needs.