When comparing Ember.js vs Mithril, the Slant community recommends Ember.js for most people. In the question“What are the best client-side JavaScript MV* frameworks?” Ember.js is ranked 4th while Mithril is ranked 6th. The most important reason people chose Ember.js is:
Route handlers for the URLs can see a wide range of possible application states, asynchronous logic in the router makes sure of Promises. And implementing makes sense.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Excellent routing
Route handlers for the URLs can see a wide range of possible application states, asynchronous logic in the router makes sure of Promises. And implementing makes sense.
Pro Increased performance because similar tasks are processed in one go
It batches bindings and DOM updates to increase performance; if similar tasks are added to a batch, the browser would only need to process them in one single go, as compared to re-computing for each task one at a time.
Pro The API is easy to understand
Ember's API are really easy to understand and work with. It has methods which allow you to harness complicated functionalities in an easy to understand way.
Pro Helps with writing simple and modular code by using Promises
Promises represent an eventual state in asynchronous logic. Having promises everywhere (almost) means you could write simple and modular code, using almost any API that Ember provides.
Pro Easy to understand documentation
The Ember Guides are well structured and very well written. The API documentation is also fantastic.
Pro Complete front-end stack
Ember is practically a complete full-stack front-end framework. It comes with it's own asset pipeline, router, services etc...

Pro Minimal need for configuration
Ember follows the philosophy of "convention over configuration" meaning that it already has almost everything configured for you, so you just have to start coding and developing your project right away.
Pro Built-in router
Ember comes with built-in routing capabilities. There's no need to install third-party plugins to be able to use routes.
Pro Debugging tool for almost every web browser
Ember also has a debugging tool called Ember Inspector which is used for debugging the client side of your app.
Pro Helps developers with keeping the structure of the application clean and simple
Ember already defines the general application structure and organization for you. This was done to prevent developers from making mistakes which would needlessly over-complicate their application. While it's still possible to go out of these practices forced to developers by the Ember authors, you still have to go out of your way to force them.
Pro Out-of-the-box CLI tool which scaffolds a new project
Ember-CLI is a very useful tool. With just a couple of commands it scaffolds the code, installs dependencies and finally compiles everything itself. It's very useful to quickstart an Ember project.
Pro Uses a relatively clean and easy to understand templating engine
Ember's preferred templating language is Handlebars. This is mainly because Handlebars is a logic-less templating language and Ember tries to keep it's logic outside the view.
Another reason why Ember benefits from Handlebars is mostly aesthetic as Handlebar's clean syntax makes for easier to read and understand templates.
Finally, Handlebars templates are compiled instead of interpreted, which means that they are much faster to load.
Pro Works great with jQuery
You can use any of jQuery’s features.
Pro Useful bindings
EmberJS provides with an extremely handy feature of advanced bindings. With this you can not only set the path to the binding value in your app but also set in which direction you want the changes to propagate to (oneway
, single
, multiple
etc).
Pro Can render the page according to any of the developer's needs because of computed properties
Having custom properties in your templates is itself a huge plus but having custom computed properties is an even greater benefit, since now you can code your custom function as a property and call it from your template. Hence rendering your page exactly according to your needs.
Pro Auto-updating templates
If you've used handlebars (Ember.js's templating is powered by HandleBars) helper tags in your code (like {{#each}}
) you won't have to worry about updating your template each time you add/remove data from your page, Handlebars will auto update your template for you.
Pro Stunning developer experience
You build products instead of constantly configuring the stuff.
Pro Uses Glimmer 2, a very fast template rendering engine
Glimmer 2, a new and very fast template rendering engine written in TypeScript, is fast due to smaller precompiled template sizes, faster parsing and initial render, and compiles at runtime to extremely efficient assembly-like append opcodes.
Pro Ember's Object model makes the framework extremely consistent
Most of Ember's components come from the Ember Object Model. It's the basis for views, controllers, models and even the framework itself. This means that the framework is extremely consistent since almost every component shares the same core functionalities and properties since they are all derived from the same object.
Pro Excellent data layer
Ember provides a built-in data layer, which makes it super simple to keep the UI in sync with the back end.
Pro Continually evolving
Ember has a great core team and community of developers who are continually improving, updating and evolving the framework. The Ember team is always planning ahead and implementing the best of the latest technologies and practices, while ensuring backwards compatability.

Pro Small, easy to learn API
Most other frameworks either offer a huge API to deal with model and view synchronization, or defer to other libraries & plugins to cater for relatively simple use cases. Mithril's API is tiny but complete. The natural reaction is to assume something is missing, but as you build you realise you incredibly fast, powerful and rich applications can be built using nothing but Mithril.

Pro Fast rendering
Mithril's loading times are very fast. This is because it's templates are compiled first and then served to the browser and because it uses a virtual DOM. The virtual DOM is a virtual tree containing all the nodes of the real DOM, every time anything changes in the virtual DOM, Mithril does not re-render the entire (real) DOM, instead it just searches and applies the differences.

Pro No need to learn another syntax to write views
Most MVC frameworks use HTML templates to render their views. They are good and useful because they are easy to read and understand. But they add more complication to an app because it's practically a new language and syntax that needs to be learned.
Mithril argues that separating markup from logic is just a separation of technologies and not concerns, so you can write Mithril views in JavaScript. Writing them in JavaScript also makes it easier to debug them (HTML templates can't be debugged).

Pro Familiar to people used to MVC
Doesn't lock you into any complicated conventions or structures, only one function is required to create either a Controller or a View. You're free to implement your architecture exactly as you want, so you can focus on the purpose of MVC, making connections between computer data and stuff in the end user's head.

Pro Small size
Weights just 8Kb gzipped and has no dependencies. A reactive stream module can be added for one extra Kb.
Pro Great documentation
Mithril has a large and expansive documentation despite it's relatively small API. Mithril's GitHub repo has more documentation than actual source code. None of that documentation is auto-generated
Pro Allows a smooth transition from other UI frameworks
One thing you need to start using Mithril is just a DOM node. With Mithril a developer is able to introduce the library step by step.
Pro Allows you to choose which JavaScript libraries to integrate in your project
Mithril gives to the developer the flexibility to chose the best JavaScript library to use for a specific task.
A huge framework like Angular instead forces you to use their API, which does not necessarily evolve as fast as the JavaScript ecosystem. Therefore you may end up in case when you are stuck using an API which is just not the best in terms of performance
Pro Can be used without build systems
It's plain old JavaScript, can be used without webpack, gulp or grunt, just include it into your HTML and start writing your app.
Pro Does not force you into a predefined structure
Mithril's API is pretty small compared to other frameworks. It forces developers to solve problems in JavaScript rather than in Mithril. Other frameworks with massive APIs force you to think in a way that suits the framework. Mithril doesn't do that.
Cons
Con Steep learning curve
Ember.js has a rather steep learning curve for beginners.
Con Too large for small projects
At 69Kb gzipped, it is one of the largest JavaScript frameworks. This means Ember might be an overkill to use on simpler projects.

Con More Ruby than JavaScript
It was written as a Ruby on Rails for JavaScript. Ends up being very frameworky and having tons of polyfills and unneeded abstractions.
Con Small API can make it unsuitable for larger more complex projects
Mithril's small API and small number of functions while helpful for small projects and applications where speed is needed, can add another layer of complexity in larger more complex applications where a more extensive API is needed out of the box.
