---
title: Experimental features in Firefox
slug: Mozilla/Firefox/Experimental_features
tags:
  - 实验的
  - 火狐
  - 特性
  - 设置
translation_of: Mozilla/Firefox/Experimental_features
---
<div>{{FirefoxSidebar}}</div><p class="summary">Mozilla发布了测试的nightly版本，用于测试新的浏览器特性。 实验性特性，例如所提议的可用的Web平台标准的实现。这个页面列出了Firefox Nightly中的一些新特性和启用方法等信息。在发布这些功能之前，你可以测试Web站点和应用程序，并确保一切都能与最新的Web技术功能协同工作。</p>

<p>你需要下载隔夜版或是开发者版，来测试下面这些实验性特性。</p>

<h2 id="HTML">HTML</h2>

<table style="height: 359px; width: 823px;" class="standard-table">
 <thead>
  <tr>
   <th scope="col">功能</th>
   <th scope="col">Firefox Nightly</th>
   <th scope="col">Firefox 开发者版</th>
   <th scope="col">Firefox 测试版</th>
   <th scope="col">Firefox 发行版</th>
   <th scope="col">Preference</th>
  </tr>
  <tr>
   <td><strong>日期和时间输入</strong>{{HTMLElement("input")}}为 <a href="/en-US/docs/Web/HTML/Element/input/date">日期</a> 和 <a href="/en-US/docs/Web/HTML/Element/input/time">时间</a> 相关的输入类型提供的新用户界面</td>
   <td>开启<br>
    <sub>(从51开始支持, 从55开始默认开启)</sub></td>
   <td>开启<br>
    <sub>(从51开始支持)</sub></td>
   <td>关闭<br>
    <sub>(从51开始支持)</sub></td>
   <td>---</td>
   <td><code>dom.forms.datetime</code></td>
  </tr>
  <tr>
   <td><strong>{{HTMLElement("dialog")}}</strong><br>
    包含与之交互的DOM元素的对话框元素。Implementation of modal dialogs and accessibility still missing.</td>
   <td>关闭<br>
    <sub>(从53开始支持)</sub></td>
   <td>关闭<br>
    <sub>(从53开始支持)</sub></td>
   <td>---</td>
   <td>---</td>
   <td><code>dom.dialog_element.enabled</code></td>
  </tr>
 </thead>
</table>

<h2 id="CSS">CSS</h2>

<table class="standard-table">
 <thead>
  <tr>
   <th scope="col">功能</th>
   <th scope="col">Firefox Nightly</th>
   <th scope="col">Firefox Developer Edition</th>
   <th scope="col">Firefox Beta</th>
   <th scope="col">Firefox Release</th>
   <th scope="col">Preference</th>
  </tr>
 </thead>
 <tbody>
  <tr>
   <td><strong>Subgrids</strong></td>
   <td>Disabled</td>
   <td>Disabled</td>
   <td>Disabled</td>
   <td>Disabled</td>
   <td><code>layout.css.grid-template-subgrid-value.enabled</code></td>
  </tr>
  <tr>
   <td><strong>Display stray control characters in CSS as hex boxes</strong><br>
    This feature renders control characters (Unicode category Cc) other than <em>tab</em> (<code>U+0009</code>), <em>line feed</em> (<code>U+000A</code>), <em>form feed</em> (<code>U+000C</code>), and <em>carriage return</em> (<code>U+000D</code>) as a hexbox when they are not expected.</td>
   <td>43</td>
   <td>43</td>
   <td><a href="https://bugzilla.mozilla.org/show_bug.cgi?id=1329613">Disabled</a></td>
   <td><a href="https://bugzilla.mozilla.org/show_bug.cgi?id=1329613">Disabled</a></td>
   <td><code>layout.css.control-characters.enabled</code> or <code>layout.css.control-characters.visible</code></td>
  </tr>
  <tr>
   <td><strong>Positioned CSS Masks</strong><br>
    A subset of CSS Masks that includes <a href="/en-US/docs/Web/CSS/CSS_Masks">longhand properties of CSS Masks</a>, as well as a change in the shorthand property</td>
   <td>51</td>
   <td>51</td>
   <td>53</td>
   <td><a href="https://bugzilla.mozilla.org/show_bug.cgi?id=1251161">Disabled</a></td>
   <td>Controlled by a compile flag (MOZ_ENABLE_MASK_AS_SHORTHAND).</td>
  </tr>
  <tr>
   <td><strong>The <code>font-display</code> descriptor for <code>@font-face</code></strong><br>
    To improve Web fonts performance, {{cssxref("@font-face")}} has an experimental {{cssxref("@font-face/font-display", "font-display")}} descriptor.</td>
   <td>关闭<br>
    <sub>(available since 46)</sub></td>
   <td>关闭<br>
    <sub>(available since 46)</sub></td>
   <td>关闭<br>
    <sub>(available since 46)</sub></td>
   <td>关闭<br>
    <sub>(available since 46)</sub></td>
   <td><code>layout.css.font-display.enabled</code></td>
  </tr>
  <tr>
   <td>
    <p><strong><code>font-variation-settings</code> 属性</strong><br>
     {{cssxref("font-variation-settings")}} 提供了OpenType或TrueType字体印刷特点的低级别的控制, by specifying the four letter axis names of the features you want to vary, along with their variation values.</p>
   </td>
   <td>关闭<br>
    <sub>(available since 53)</sub></td>
   <td>关闭<br>
    <sub>(available since 53)</sub></td>
   <td>关闭<br>
    <sub>(available since 53)</sub></td>
   <td>关闭<br>
    <sub>(available since 53)</sub></td>
   <td>
    <p><code>layout.css.font-variations.enabled</code><br>
     Functions only in Mac OS Sierra (and later).<br>
     <br>
     For the downloadable fonts on axis-praxis, you also need <code>gfx.downloadable_fonts.keep_variation_tables</code> (in Firefox 54 and later)</p>
   </td>
  </tr>
  <tr>
   <td><strong><code>touch-action</code> CSS 属性</strong><br>
    The {{cssxref("touch-action")}} CSS property is part of the {{SpecName("Pointer Events")}} specification and allows you to specify how and in what way the user is able to manipulate an object by touch.</td>
   <td>50</td>
   <td>—</td>
   <td>—</td>
   <td>—</td>
   <td><code>layout.css.touch_action.enabled</code></td>
  </tr>
  <tr id="shape-outside">
   <td>
    <p><strong>The <code>shape-outside</code> CSS property</strong><br>
     The {{cssxref("shape-outside")}} CSS property is part of the {{SpecName("CSS Shapes")}} specification and allows you to specify a float area causing inline contents to wrap around a shape.</p>

    <p>Firefox currently implements the <code>&lt;shape-box&gt;</code> values ({{bug(1309467)}}) as well as the <code>circle()</code> ({{bug(1311244)}}), <code>ellipse()</code> ({{bug(1326406)}}), and <code>polygon()</code> ({{bug(1326409)}}) functions.</p>
   </td>
   <td>关闭<br>
    <sub>(available since 53)</sub></td>
   <td>—</td>
   <td>—</td>
   <td>—</td>
   <td><code>layout.css.shape-outside.enabled</code></td>
  </tr>
  <tr>
   <td><strong>The <code>contain</code> CSS property</strong><br>
    The {{cssxref("contain")}} CSS property is part of the {{SpecName("CSS Containment")}} specification and allows you to indicate that an element and its contents are independent of the rest of the document tree, allowing {{Glossary("User agent", "user agents")}} to optimize the rendering of a page.</td>
   <td>关闭<br>
    <sub>(available since 45)</sub></td>
   <td>关闭<br>
    <sub>(available since 45)</sub></td>
   <td>关闭<br>
    <sub>(available since 45)</sub></td>
   <td>关闭<br>
    <sub>(available since 45)</sub></td>
   <td><code>layout.css.contain.enabled</code></td>
  </tr>
  <tr id="column-span">
   <td>
    <p><strong>The <code>column-span</code> CSS property</strong><br>
     The {{cssxref("column-span")}} CSS property is part of the {{SpecName("CSS3 Multicol")}} specification and allows you to specify how many columns an element spans across.</p>

    <p>Firefox currently only parses the property ({{bug(1339298)}}), it's not actually implemented yet ({{bug(616436)}}).</p>
   </td>
   <td>关闭<br>
    <sub>(recognized since 55, but not implemented yet)</sub></td>
   <td>—</td>
   <td>—</td>
   <td>—</td>
   <td><code>layout.css.column-span.enabled</code></td>
  </tr>
  <tr>
   <td><strong>The <code>frames()</code> timing function</strong><br>
    See <a href="https://developer.mozilla.org/en-US/docs/Web/CSS/single-transition-timing-function#The_frames()_class_of_timing-functions">The frames() class of timing-functions</a> for more details.</td>
   <td>开启</td>
   <td><sub>N/A</sub></td>
   <td>关闭<br>
    <sub>(available since 55)</sub></td>
   <td>关闭<br>
    <sub>(available since 55)</sub></td>
   <td>None</td>
  </tr>
 </tbody>
</table>

<h2 id="JavaScript">JavaScript</h2>

<p id="ECMAScript_2016">See also <a href="/en-US/docs/Web/JavaScript/New_in_JavaScript/ECMAScript_Next_support_in_Mozilla">ECMAScript Next support</a> for implemented features of ECMAScript 2016 and later, that are not experimental and thus available without preferences in Firefox Release.</p>

<table class="standard-table">
 <thead>
  <tr>
   <th scope="col">Feature</th>
   <th scope="col">Firefox Nightly</th>
   <th scope="col">Firefox Developer Edition</th>
   <th scope="col">Firefox Beta</th>
   <th scope="col">Firefox Release</th>
   <th scope="col">Preference</th>
  </tr>
 </thead>
 <tbody>
  <tr>
   <td><strong>Additions to the <code>ArrayBuffer</code> object</strong><br>
    Adds the {{jsxref("ArrayBuffer.transfer()")}} that returns a new <code>ArrayBuffer</code> whose contents have been taken from the <code>oldBuffer</code>'s data (<a href="https://gist.github.com/lukewagner/2735af7eea411e18cf20">spec</a>).</td>
   <td>36</td>
   <td>Disabled</td>
   <td>Disabled</td>
   <td>Disabled</td>
   <td>None</td>
  </tr>
  <tr>
   <td><strong>TypedObject objects</strong> (<a href="https://github.com/dslomov-chromium/typed-objects-es7">spec</a>)</td>
   <td>Enabled</td>
   <td>Disabled</td>
   <td>Disabled</td>
   <td>Disabled</td>
   <td>None</td>
  </tr>
  <tr>
   <td><a href="/en-US/docs/Web/JavaScript/Reference/Global_Objects/SIMD">SIMD</a> (<a href="https://github.com/johnmccutchan/ecmascript_simd">specification and polyfill</a>)</td>
   <td>Enabled</td>
   <td>Disabled</td>
   <td>Disabled</td>
   <td>Disabled</td>
   <td>None</td>
  </tr>
  <tr>
   <td><strong>ECMAScript modules</strong><br>
    Allows you to use native ECMAScript modules, for example defining modules with <code>&lt;script type="module"&gt;</code>, defining fallback scripts with <code>&lt;script nomodule&gt;</code>, and <a href="/en-US/docs/Web/JavaScript/Reference/Statements/import">importing</a> code features that have been <a href="/en-US/docs/Web/JavaScript/Reference/Statements/export">exported</a> from modules.</td>
   <td>Disabled</td>
   <td>Disabled</td>
   <td>Disabled</td>
   <td>Disabled</td>
   <td><code>dom.moduleScripts.enabled</code></td>
  </tr>
 </tbody>
</table>

<h2 id="APIs">APIs</h2>

<h3 id="Canvas_WebGL">Canvas &amp; WebGL</h3>

<table class="standard-table">
 <thead>
  <tr>
   <th scope="col">Feature</th>
   <th scope="col">Firefox Nightly</th>
   <th scope="col">Firefox Developer Edition</th>
   <th scope="col">Firefox Beta</th>
   <th scope="col">Firefox Release</th>
   <th scope="col">Preference</th>
  </tr>
 </thead>
 <tbody>
  <tr>
   <td><strong><code>WEBGL_debug_renderer_info</code> extension</strong><br>
    The {{domxref("WEBGL_debug_renderer_info")}} extension allows you to transmit information useful to help debugging problems to the server.</td>
   <td>42</td>
   <td>42</td>
   <td><a href="https://bugzilla.mozilla.org/show_bug.cgi?id=742798">Disabled</a></td>
   <td><a href="https://bugzilla.mozilla.org/show_bug.cgi?id=742798">Disabled</a></td>
   <td><code>webgl.enable-debug-renderer-info</code></td>
  </tr>
  <tr>
   <td><strong>OffscreenCanvas</strong><br>
    The {{domxref("OffscreenCanvas")}} interface provides a canvas that can be rendered off screen. It is available in both the window and <a href="/en-US/docs/Web/API/Web_Workers_API">worker</a> contexts.</td>
   <td>Disabled<br>
    <sub>(available since 44)</sub></td>
   <td>Disabled<br>
    <sub>(available since 44)</sub></td>
   <td>Disabled<br>
    <sub>(available since 44)</sub></td>
   <td>Disabled<br>
    <sub>(available since 44)</sub></td>
   <td><code>gfx.offscreencanvas.enabled</code></td>
  </tr>
  <tr>
   <td><strong><a href="/en-US/docs/Web/API/Canvas_API/Tutorial/Hit_regions_and_accessibility">Hit regions</a></strong><br>
    Whether the mouse coordinates are within a particular area on the canvas is a common problem to solve. The hit region API allows you define an area of your canvas and provides another possibility to expose interactive content on a canvas to accessibility tools.</td>
   <td>Disabled<br>
    <sub>(available since 30)</sub></td>
   <td>Disabled<br>
    <sub>(available since 30)</sub></td>
   <td>Disabled<br>
    <sub>(available since 30)</sub></td>
   <td>Disabled<br>
    <sub>(available since 30)</sub></td>
   <td><code>canvas.hitregions.enabled</code></td>
  </tr>
 </tbody>
</table>

<h3 id="DOM">DOM</h3>

<table class="standard-table">
 <thead>
  <tr>
   <th scope="col">Feature</th>
   <th scope="col">Firefox Nightly</th>
   <th scope="col">Firefox Developer Edition</th>
   <th scope="col">Firefox Beta</th>
   <th scope="col">Firefox Release</th>
   <th scope="col">Preference</th>
  </tr>
 </thead>
 <tbody>
  <tr>
   <td><strong>Mac上的WebVR API 1.1</strong><br>
    <a href="/en-US/docs/Web/API/WebVR_API">WebVR API</a> 允许你控制并和使用虚拟现实设备。</td>
   <td>Enabled</td>
   <td>Disabled</td>
   <td>Disabled</td>
   <td>Disabled</td>
   <td><code>dom.vr.enabled</code></td>
  </tr>
  <tr>
   <td><strong>游戏手柄扩展</strong><br>
    <a href="/en-US/docs/Web/API/Gamepad_API#Experimental_Gamepad_extensions">The Gamepad Extensions</a> provide access to additional functionality such as pose information in the case of WebVR controllers, and haptic actuator control (e.g. controller vibration hardware).</td>
   <td>Enabled</td>
   <td>Enabled</td>
   <td>Enabled</td>
   <td>Disabled</td>
   <td><code>dom.gamepad-extensions.enabled</code></td>
  </tr>
  <tr>
   <td><strong>Experimental fetch controller/signal/observer interfaces</strong><br>
    Also known as "cancellable fetch", <a href="/en-US/docs/Web/API/Fetch_API#Experimental_fetch_controllersignalobserver_interfaces">these interfaces</a> contain functionality to allow fetch request operations to be observed and controlled during their lifetimes.</td>
   <td>Disabled<br>
    <sub>(Available since 55)</sub></td>
   <td>Disabled</td>
   <td>Disabled</td>
   <td>Disabled</td>
   <td><code>dom.fetchObserver.enabled</code> and <code>dom.fetchController.enabled</code> (not in <code>about:config</code> by default; you must set them yourself).</td>
  </tr>
  <tr>
   <td><strong>FlyWeb</strong><br>
    <a href="https://flyweb.github.io/">FlyWeb</a> is a project at Mozilla focused on bringing a new set of APIs to the browser for advertising and discovering local-area web servers.</td>
   <td>51</td>
   <td>Disabled</td>
   <td>Disabled</td>
   <td>Disabled</td>
   <td><code>dom.flyweb.enabled</code></td>
  </tr>
  <tr>
   <td><code><strong>HTMLMediaElement.seekToNextFrame()</strong></code><br>
    Part of an experimentation process around support non-real-time access to media for tasks including filtering, editing, and so forth, the {{domxref("HTMLMediaElement.seekToNextFrame()")}} advances the the current play position to the next frame in the media.</td>
   <td>49<br>
    <sub>(Fundamental update in version 50)</sub></td>
   <td>49<br>
    <sub>(Fundamental update in version 50)</sub></td>
   <td>Disabled</td>
   <td>Disabled</td>
   <td><code>media.seekToNextFrame.enabled</code></td>
  </tr>
  <tr>
   <td><strong><code>GeometryUtils.getBoxQuads()</code></strong> ({{bug(917755)}})</td>
   <td>31</td>
   <td>31</td>
   <td><a href="https://bugzilla.mozilla.org/show_bug.cgi?id=1107559">Disabled</a></td>
   <td><a href="https://bugzilla.mozilla.org/show_bug.cgi?id=1107559">Disabled</a></td>
   <td><code>layout.css.getBoxQuads.enabled</code></td>
  </tr>
  <tr>
   <td><strong><code>GeometryUtils.convertPointFromNode()</code></strong>,<br>
    <strong><code>GeometryUtils.RectFromNode()</code></strong>, and<br>
    <code><strong>GeometryUtils.convertQuadFromNode()</strong></code><br>
    ({{bug(918189)}})</td>
   <td>31</td>
   <td>31</td>
   <td><a href="https://bugzilla.mozilla.org/show_bug.cgi?id=1107559">Disabled</a></td>
   <td><a href="https://bugzilla.mozilla.org/show_bug.cgi?id=1107559">Disabled</a></td>
   <td><code>layout.css.convertFromNode.enabled</code></td>
  </tr>
  <tr>
   <td><strong><code>Node.rootNode</code></strong><br>
    The {{domxref("Node.rootNode")}} property returns a {{domxref("Node")}} object representing the topmost node in the tree, or the current node if it's the topmost node in the tree.<br>
    <em>This feature is kept experimental as its naming poses Web compatibility problems. It will be renamed in the future.</em></td>
   <td>48</td>
   <td>48</td>
   <td><a href="https://bugzilla.mozilla.org/show_bug.cgi?id=1269155">Disabled</a></td>
   <td><a href="https://bugzilla.mozilla.org/show_bug.cgi?id=1269155">Disabled</a></td>
   <td><code>dom.node.rootNode.enabled</code></td>
  </tr>
  <tr>
   <td><strong>Performance Observer API</strong><br>
    The {{domxref("PerformanceObserver")}} interface is used to <em>observe</em> performance measurement events and be notified of new <a href="/en-US/docs/Web/API/PerformanceEntry" title="The PerformanceEntry object encapsulates a single performance metric that is part of the performance timeline. A performance entry can be directly created by making a performance mark or measure (for example by calling the mark() method) at an explicit point in an application. Performance entries are also created in indirect ways such as loading a resource (such as an image).">performance entries</a> as they are recorded in the browser's <em>performance timeline</em>.</td>
   <td>49</td>
   <td>Disabled</td>
   <td>Disabled</td>
   <td>Disabled</td>
   <td><code>dom.enable_performance_observer</code></td>
  </tr>
  <tr>
   <td><strong>WebVTT Regions API</strong><br>
    <a href="/en-US/docs/Web/API/Web_Video_Text_Tracks_Format">WebVTT</a> regions are parts of the video viewport that provide a rendering area for WebVTT cues. The {{domxref("VTTRegion")}} is the interface exposing the WebVTT cues.<br>
    <em>This interface is considered to be in flux and isn't therefore activated in any version by default.</em></td>
   <td>Disabled<br>
    <sub>(Experimental implementation since version 30)</sub></td>
   <td>Disabled</td>
   <td>Disabled</td>
   <td>Disabled</td>
   <td><code>media.webvtt.regions.enabled</code></td>
  </tr>
  <tr>
   <td><strong>音频和视频轨道支持</strong><br>
    Implements {{domxref("HTMLMediaElement.audioTracks")}} and {{domxref("HTMLMediaElement.videoTracks")}}.<br>
    <em>Firefox doesn't support multiple audio or video tracks, preventing the most common use cases for these properties to work properly. That's why these properties are not activated by default in any version.</em></td>
   <td>Disabled<br>
    <sub>(Experimental implementation since version 33)</sub></td>
   <td>Disabled</td>
   <td>Disabled</td>
   <td>Disabled</td>
   <td><code>media.track.enabled</code></td>
  </tr>
  <tr>
   <td><strong>Better value for <code>Event.timestamp</code></strong><br>
    The property {{domxref("Event.timestamp")}} is returning a {{domxref("DOMHighResTimeStamp")}}, which is now relative to the Unix epoch.</td>
   <td>32 (Windows)<br>
    43 (Linux)</td>
   <td>32 (Windows)<br>
    43 (Linux)</td>
   <td><a href="https://bugzilla.mozilla.org/show_bug.cgi?id=1026804">Disabled</a></td>
   <td><a href="https://bugzilla.mozilla.org/show_bug.cgi?id=1026804">Disabled</a></td>
   <td><code>media.track.enabled</code></td>
  </tr>
  <tr id="pointer-events">
   <td><strong>指针事件</strong></td>
   <td>50</td>
   <td>Disabled</td>
   <td>Disabled</td>
   <td>Disabled</td>
   <td><code>dom.w3c_pointer_events.enabled</code></td>
  </tr>
  <tr>
   <td><strong>Pointer Events {{domxref("PointerEvent.tangentialPressure")}} and {{domxref("PointerEvent.twist")}}</strong></td>
   <td>54</td>
   <td>Disabled</td>
   <td>Disabled</td>
   <td>Disabled</td>
   <td><code>dom.w3c_pointer_events.enabled</code></td>
  </tr>
  <tr>
   <td><strong>Intersection Observer API</strong><br>
    The {{domxref("Intersection Observer API")}} allows you to configure a callback that is called whenever one item, called a target, intersects either the device viewport or a specified element called.</td>
   <td>Disabled<br>
    <sub>(available since 53)</sub></td>
   <td>—</td>
   <td>—</td>
   <td>—</td>
   <td><code>dom.IntersectionObserver.enabled</code></td>
  </tr>
  <tr>
   <td><strong><a href="/en-US/docs/Web/API/Web_Animations_API">Web Animations API: KeyframeEffect and KeyframeEffectReadOnly</a></strong><br>
    The {{domxref("KeyframEffectReadOnly()", "KeyframeEffectReadOnly.KeyframeEffectReadOnly()")}} and {{domxref("KeyframeEffect()", "KeyframeEffect.KeyframeEffect()")}} constructors can be used to clone existing {{domxref("KeyframeEffectReadOnly")}} object instances by being given the object to clone as their only parameter (see {{bug(1273784)}}.)</td>
   <td>52</td>
   <td>52</td>
   <td>Disabled</td>
   <td>Disabled</td>
   <td>None</td>
  </tr>
  <tr>
   <td><strong>{{domxref("PromiseRejectionEvent")}} and related features</strong><br>
    Providing a way to monitor and more finely control the rejection of Promises.<br>
     </td>
   <td>Disabled<br>
    <sub>(available since 55)</sub></td>
   <td>Disabled</td>
   <td>Disabled</td>
   <td>Disabled</td>
   <td><code>dom.promise_rejection_events.enabled</code></td>
  </tr>
  <tr>
   <td><strong><a href="/en-US/docs/Web/API/Payment_Request_API">Payment Request API</a></strong><br>
    为网络支付提供的一个API。</td>
   <td>Disabled<br>
    <sub>(available since 55)</sub></td>
   <td>Disabled<br>
    <sub>(available since 55)</sub></td>
   <td>Disabled<br>
    <sub>(available since 55)</sub></td>
   <td>Disabled<br>
    <sub>(available since 55)</sub></td>
   <td><code>dom.payments.request.enabled</code></td>
  </tr>
 </tbody>
</table>

<h3 id="WebRTC">WebRTC</h3>

<table class="standard-table">
 <thead>
  <tr>
   <th scope="col">Feature</th>
   <th scope="col">Firefox Nightly</th>
   <th scope="col">Firefox Developer Edition</th>
   <th scope="col">Firefox Beta</th>
   <th scope="col">Firefox Release</th>
   <th scope="col">Preference</th>
  </tr>
 </thead>
 <tbody>
  <tr>
   <td><strong>TCP ICE candidates</strong><br>
    ICE candidates that use TCP rather than UDP are considered during ICE negotiation.</td>
   <td>
    <p>Disabled<br>
     41</p>

    <p>Enabled<br>
     54</p>
   </td>
   <td>Disabled<br>
    41</td>
   <td>Disabled<br>
    41</td>
   <td>Disabled<br>
    41</td>
   <td><code>media.peerconnection.ice.tcp</code></td>
  </tr>
 </tbody>
</table>

<h2 id="开发者工具">开发者工具</h2>

<table class="standard-table">
 <thead>
  <tr>
   <th scope="col">Feature</th>
   <th scope="col">Firefox Nightly</th>
   <th scope="col">Firefox Developer Edition</th>
   <th scope="col">Firefox Beta</th>
   <th scope="col">Firefox Release</th>
   <th scope="col">Preference</th>
  </tr>
 </thead>
 <tbody>
  <tr id="new-debugger-frontend">
   <td><strong>Debugger rewrite in HTML</strong></td>
   <td>52</td>
   <td>52</td>
   <td>Disabled</td>
   <td>Disabled</td>
   <td><code>devtools.debugger.new-debugger-frontend</code></td>
  </tr>
  <tr id="new-console-frontend">
   <td><strong>Console rewrite in HTML</strong></td>
   <td>52</td>
   <td>Disabled</td>
   <td>Disabled</td>
   <td>Disabled</td>
   <td><code>devtools.webconsole.new-frontend-enabled</code></td>
  </tr>
  <tr id="performance-tool-options">
   <td><strong>Experimental Performance tool options</strong><br>
    Enables options in the UI for JIT optimizations, memory, etc.</td>
   <td>41</td>
   <td>Disabled</td>
   <td>Disabled</td>
   <td>Disabled</td>
   <td><code>devtools.performance.ui.experimental</code></td>
  </tr>
  <tr id="layout-side-panel">
   <td><strong>Layout side panel</strong><br>
    The Layout side panel allows to inspect and manage different CSS layout types like <a href="/en-US/docs/Web/CSS/CSS_Grid_Layout">CSS Grid Layout</a>.</td>
   <td>Disabled<br>
    <sub>(available since 52)</sub></td>
   <td>Disabled<br>
    <sub>(available since 52)</sub></td>
   <td>Disabled<br>
    <sub>(available since 52)</sub></td>
   <td>Disabled<br>
    <sub>(available since 52)</sub></td>
   <td><code>devtools.layoutview.enabled</code></td>
  </tr>
 </tbody>
</table>

<h2 id="其他">其他</h2>

<table class="standard-table">
 <thead>
  <tr>
   <th scope="col">Feature</th>
   <th scope="col">Firefox Nightly</th>
   <th scope="col">Firefox Developer Edition</th>
   <th scope="col">Firefox Beta</th>
   <th scope="col">Firefox Release</th>
   <th scope="col">Preference</th>
  </tr>
  <tr>
   <td><a href="https://support.mozilla.org/t5/Other/How-to-add-a-shortcut-to-a-website-on-Android/ta-p/21992"><strong>添加到主屏幕</strong></a><br>
    The <code>icons</code>, <code>name</code>, <code>short_name</code>, and <code>theme_color</code> fields of the <a href="/en-US/docs/Web/Manifest">Web App Manifest</a> (if present) can now be as the source of the homescreen/apps window icons, apps window title, homescreen icon title, and apps window color (respectively) for "Add to home screen" (Firefox Mobile only).</td>
   <td>关闭<br>
    <sub>(available since 53)</sub></td>
   <td>关闭<br>
    <sub>(available since 53)</sub></td>
   <td>关闭<br>
    <sub>(available since 53)</sub></td>
   <td>关闭<br>
    <sub>(available since 52)</sub></td>
   <td><code>manifest.install.enabled</code></td>
  </tr>
  <tr>
   <td><strong>TLS 1.3</strong></td>
   <td>开启</td>
   <td>开启</td>
   <td>关闭</td>
   <td>关闭</td>
   <td><code>security.tls.version.max</code> to <code>4</code></td>
  </tr>
 </thead>
</table>

<h2 id="See_also">See also</h2>

<ul>
 <li><a href="/en-US/docs/Mozilla/Firefox/Releases">Firefox 开发者发行日志</a></li>
 <li><a href="https://nightly.mozilla.org/">Firefox Nightly</a></li>
 <li><a href="https://www.mozilla.org/en-US/firefox/developer/">Firefox 开发者版本</a></li>
</ul>