# Phoenix LiveView

![Actions Status](

Phoenix LiveView enables rich, real-time user experiences
with server-rendered HTML. [See the initial announcement](

## Learning

See our existing comprehensive docs and examples to get up to speed:

  * [Phoenix.LiveView docs for Elixir and JavaScript usage](
  * [Phoenix.LiveViewTest for testing docs](
  * [LiveView example repo]( with a handful of examples from Weather widgets, autocomplete search, and games like Snake or Pacman

## Installation

There are currently two methods for installing LiveView. For projects that
require more stability, it is recommended that you install using the
[installation guide on HexDocs](
If you want to use the latest features, you should follow the instructions
given in the markdown file [here](guides/introduction/

## What makes LiveView unique?

LiveView is server centric. You no longer have to worry about managing
both client and server to keep things in sync. LiveView automatically
updates the client as changes happen on the server.

LiveView is first rendered statically as part of regular HTTP requests,
which provides quick times for "First Meaningful Paint", in addition to
helping search and indexing engines.

Then LiveView uses a persistent connection between client and server.
This allows LiveView applications to react faster to user events as
there is less work to be done and less data to be sent compared to
stateless requests that have to authenticate, decode, load, and encode
data on every request.

When LiveView was first announced, many developers from different
backgrounds got inspired about the potential unlocked by LiveView to
build rich, real-time user experiences. We believe LiveView is built
on top of a solid foundation that makes LiveView hard to replicate
anywhere else:

  * LiveView is built on top of the Elixir programming language and
    functional programming, which provides a great model for reasoning
    about your code and how your LiveView changes over time.

  * By building on top of a [scalable platform](,
    LiveView scales well vertically (from small to large instances)
    and horizontally (by adding more instances). This allows you to
    continue shipping features when more and more users join your
    application, instead of dealing with performance issues.

  * LiveView applications are *distributed and real-time*. A LiveView
    app can push events to users as those events happen anywhere in
    the system. Do you want to notify a user that their best friend
    just connected? This is easily done without a single-line of
    JavaScript and with no extra external dependencies.

  * LiveView performs diff tracking: whenever you change a value on
    the server, LiveView will send to the client only the values that
    changed, drastically reducing the latency and the amount of data
    sent over the wire. This is achievable thanks to Elixir's
    immutability and its ability to treat code as data.

  * LiveView separates the static and dynamic parts of your templates.
    When you first render a page, Phoenix LiveView renders and sends
    the whole template to the browser. Then, for any new update, only
    the modified dynamic content is resent. This alongside diff tracking
    makes it so LiveView only sends a few bytes on every update, instead
    of sending kilobytes on every other user interaction - which would
    be detrimental to the user experience;

Finally, LiveView has been used by many developers and companies around
the world, which helped us close the gaps in our feature set and make
sure LiveView is ready for prime time. For example, you will find:

  * a latency simulator allows developers to simulate how their
    application behave under slow connections

  * `LiveComponent`s help developers compartmentalize their templates,
    state, and event handling into reusable bits, which is essential
    in large applications

  * Live navigation enriches links and redirects to only load the
    minimum amount of content as users navigate between pages

  * Fine-grained control for handling client events, DOM patching,
    rate limiting, and more

In other words, LiveView provides a rich feature set for great
developer and user experiences.

## Browser Support

All current Chrome, Safari, Firefox, and MS Edge are supported.
IE11 support is available with the following polyfills:

$ npm install --save --prefix assets mdn-polyfills url-search-params-polyfill formdata-polyfill child-replace-with-polyfill classlist-polyfill @webcomponents/template shim-keyboard-event-key

Note: The `shim-keyboard-event-key` polyfill is also required for [MS Edge 12-18](

// assets/js/app.js
import "mdn-polyfills/Object.assign"
import "mdn-polyfills/CustomEvent"
import "mdn-polyfills/String.prototype.startsWith"
import "mdn-polyfills/Array.from"
import "mdn-polyfills/NodeList.prototype.forEach"
import "mdn-polyfills/Element.prototype.closest"
import "mdn-polyfills/Element.prototype.matches"
import "mdn-polyfills/Node.prototype.remove"
import "child-replace-with-polyfill"
import "url-search-params-polyfill"
import "formdata-polyfill"
import "classlist-polyfill"
import "@webcomponents/template"
import "shim-keyboard-event-key"

import {Socket} from "phoenix"
import LiveSocket from "phoenix_live_view"