Skip to content
Merged
14 changes: 11 additions & 3 deletions README.md
Original file line number Diff line number Diff line change
Expand Up @@ -42,6 +42,12 @@ sync'd July 30, 2025

| Demo name | Description and docs | Source code & Readme | Live demo page |
|---|---|---|---|
| View `@font-palette-values` CSS at-rules | Used for [View `@font-palette-values` at-rules](https://learn.microsoft.com/microsoft-edge/devtools/css/reference#view-font-palette-values-at-rules) in _CSS features reference_. | [/at-rules-font-palette-values/](https://github.com/MicrosoftEdge/Demos/tree/main/at-rules-font-palette-values/) | [View `@font-palette-values` CSS at-rules](https://microsoftedge.github.io/Demos/at-rules-font-palette-values/) demo |
| View `@position-try` CSS at-rules | Used for [View `@position-try` at-rules](https://learn.microsoft.com/microsoft-edge/devtools/css/reference#view-position-try-at-rules) in _CSS features reference_. | [/at-rules-position-try/](https://github.com/MicrosoftEdge/Demos/tree/main/at-rules-position-try/) | [View `@position-try` CSS at-rules](https://microsoftedge.github.io/Demos/at-rules-position-try/) demo |
| View `@property` CSS at-rules | Used for [View `@property` at-rules](https://learn.microsoft.com/microsoft-edge/devtools/css/reference#view-property-at-rules) in _CSS features reference_. | [/at-rules-property/](https://github.com/MicrosoftEdge/Demos/tree/main/at-rules-property/) | [View `@property` CSS at-rules](https://microsoftedge.github.io/Demos/at-rules-property/) demo |
| View `@scope` CSS at-rules | [View `@scope` at-rules](https://learn.microsoft.com/microsoft-edge/devtools/css/reference#view-scope-at-rules) in _CSS features reference_. | [/at-rules-scope/](https://github.com/MicrosoftEdge/Demos/tree/main/at-rules-scope/) | [View `@scope` CSS at-rules](https://microsoftedge.github.io/Demos/at-rules-scope/) demo |
| View `@supports` CSS at-rules | Used for [View `@supports` at-rules](https://learn.microsoft.com/microsoft-edge/devtools/css/reference#view-supports-at-rules) in _CSS features reference_. | [/at-rules-supports/](https://github.com/MicrosoftEdge/Demos/tree/main/at-rules-supports/) | [View `@supports` CSS at-rules](https://microsoftedge.github.io/Demos/at-rules-supports/) demo |
| Cascade layers | Used for [View cascade layers](https://learn.microsoft.com/microsoft-edge/devtools/css/reference#view-cascade-layers) in _CSS features reference_. | [/cascade-layers/](https://github.com/MicrosoftEdge/Demos/tree/main/cascade-layers/) | [Cascade layers](https://microsoftedge.github.io/Demos/cascade-layers/) demo |
| CSS mirroring sourcemaps | Used for [Update .css files from within the Styles tab (CSS mirror editing)](https://learn.microsoft.com/microsoft-edge/visual-studio-code/microsoft-edge-devtools-extension/css-mirror-editing-styles-tab) for the DevTools extension for Visual Studio Code. | [/css-mirroring-sourcemaps-demo/](https://github.com/MicrosoftEdge/Demos/tree/main/css-mirroring-sourcemaps-demo) | n/a |
| To Do app | Simple To Do app with vanilla JavaScript. Used for various articles in the [Microsoft Edge DevTools documentation](https://learn.microsoft.com/microsoft-edge/devtools/landing). | [/demo-to-do/](https://github.com/MicrosoftEdge/Demos/tree/main/demo-to-do) | [My tasks](https://microsoftedge.github.io/Demos/demo-to-do/) demo |
| Detached DOM elements | Chat-like demo. Used for [Debug DOM memory leaks ("Detached elements" profiling type)](https://learn.microsoft.com/microsoft-edge/devtools/memory-problems/dom-leaks-memory-tool-detached-elements). | [/detached-elements/](https://github.com/MicrosoftEdge/Demos/tree/main/detached-elements) | [Detached DOM elements](https://microsoftedge.github.io/Demos/detached-elements/) demo |
Expand All @@ -55,24 +61,26 @@ sync'd July 30, 2025
| CSS Examples | Used for [Get started viewing and changing CSS](https://learn.microsoft.com/microsoft-edge/devtools/css/). | [/devtools-css-get-started/](https://github.com/MicrosoftEdge/Demos/tree/main/devtools-css-get-started) | [CSS Examples](https://microsoftedge.github.io/Demos/devtools-css-get-started/) demo |
| DOM Examples | Used for [Get started viewing and changing the DOM](https://learn.microsoft.com/microsoft-edge/devtools/dom/). | [/devtools-dom-get-started/](https://github.com/MicrosoftEdge/Demos/tree/main/devtools-dom-get-started) | [DOM Examples](https://microsoftedge.github.io/Demos/devtools-dom-get-started/) demo |
| Explain Console errors and warnings in Copilot in Edge | Generates errors in the Console that can then be explained by using Copilot in Edge. | [/devtools-explain-error/](https://github.com/MicrosoftEdge/Demos/tree/main/devtools-explain-error) | [Explain Console errors and warnings in Copilot in Edge](https://microsoftedge.github.io/Demos/devtools-explain-error/) demo |
| Inspect tool | Used for [Analyze pages using the Inspect tool](https://learn.microsoft.com/microsoft-edge/devtools/css/inspect). | [/devtools-inspect/](https://github.com/MicrosoftEdge/Demos/tree/main/devtools-inspect) | [Inspect tool demo](https://microsoftedge.github.io/Demos/devtools-inspect/) |
| Inspect CSS Grid | Used for [Inspect CSS Grid](https://learn.microsoft.com/microsoft-edge/devtools/css/grid). | [/devtools-grid/](https://github.com/MicrosoftEdge/Demos/tree/main/devtools-grid) | [Inspect CSS Grid](https://microsoftedge.github.io/Demos/devtools-grid/) demo |
| Inspect tool | Used for [Analyze pages using the Inspect tool](https://learn.microsoft.com/microsoft-edge/devtools/css/inspect). | [/devtools-inspect/](https://github.com/MicrosoftEdge/Demos/tree/main/devtools-inspect) | [Inspect tool demo](https://microsoftedge.github.io/Demos/devtools-inspect/) |
| Debugging JavaScript that adds two numbers | Used for [Get started debugging JavaScript](https://learn.microsoft.com/microsoft-edge/devtools/javascript/). | [/devtools-js-get-started/](https://github.com/MicrosoftEdge/Demos/tree/main/devtools-js-get-started) | [Debugging JavaScript with Microsoft Edge DevTools](https://microsoftedge.github.io/Demos/devtools-js-get-started/) demo |
| Memory heap snapshot | Used for [Record heap snapshots using the Memory tool ("Heap snapshot" profiling type)](https://learn.microsoft.com/microsoft-edge/devtools/memory-problems/heap-snapshots). | [/devtools-memory-heap-snapshot/](https://github.com/MicrosoftEdge/Demos/tree/main/devtools-memory-heap-snapshot) | n/a |
| Network tool reference | Used for [Network features reference](https://learn.microsoft.com/microsoft-edge/devtools/network/reference). | [/devtools-network-reference/](https://github.com/MicrosoftEdge/Demos/tree/main/devtools-network-reference) | [Network tool reference demo](https://microsoftedge.github.io/Demos/devtools-network-reference/) |
| **Performance** tool Activity Tabs | Used for [View activities in a table](https://learn.microsoft.com/microsoft-edge/devtools/performance/reference#view-activities-in-a-table) in _Performance features reference_, about the **Performance** tool's **Bottom-up**, **Call tree**, and **Event log** tabs. | [/devtools-performance-activitytabs/](https://github.com/MicrosoftEdge/Demos/tree/main/devtools-performance-activitytabs) | [Activity Tabs demo](https://microsoftedge.github.io/Demos/devtools-performance-activitytabs/) |
| Sluggish Animation | Used for [Analyze runtime performance (tutorial)](https://learn.microsoft.com/microsoft-edge/devtools/performance/). | [/devtools-performance-get-started/](https://github.com/MicrosoftEdge/Demos/tree/main/devtools-performance-get-started) | [Sluggish Animation](https://microsoftedge.github.io/Demos/devtools-performance-get-started/) demo |
| postMessage Trace Events | Tests `postMessage` trace events in the **Performance** tool. Used for [View messages between windows, iframes, and dedicated workers](https://learn.microsoft.com/microsoft-edge/devtools/performance/reference#view-messages-between-windows-iframes-and-dedicated-workers) in _Performance features reference_. | [/devtools-postmessage-perf-timeline/](https://github.com/MicrosoftEdge/Demos/tree/main/devtools-postmessage-perf-timeline) | [postMessage Trace Events demo](https://microsoftedge.github.io/Demos/devtools-postmessage-perf-timeline/) |
| CSS :target pseudo-class | Used for [Support forcing the :target CSS state](https://learn.microsoft.com/microsoft-edge/devtools/whats-new/2021/01/devtools#support-forcing-the-target-css-state) in _What's New in DevTools (Microsoft Edge 89)_. | [/devtools-target-pseudo/](https://github.com/MicrosoftEdge/Demos/tree/main/devtools-target-pseudo) | [CSS :target pseudo-class demo](https://microsoftedge.github.io/Demos/devtools-target-pseudo/) |
| Emulate a focused page | Used for [Emulate a focused page](https://learn.microsoft.com/microsoft-edge/devtools/css/reference#emulate-a-focused-page) in _CSS features reference_. | [/emulate-focused-page/](https://github.com/MicrosoftEdge/Demos/tree/main/emulate-focused-page/) | [Emulate a focused page](https://microsoftedge.github.io/Demos/emulate-focused-page/) demo |
| Exploring the universe | Used for [Monitor Core Web Vitals metrics](../performance/overview.md#monitor-core-web-vitals-metrics) in _Performance tool: Analyze your website's performance_. | [/exploring-the-universe/](https://github.com/MicrosoftEdge/Demos/tree/main/exploring-the-universe) | [Exploring the universe](https://microsoftedge.github.io/Demos/exploring-the-universe/) demo |
| Heap Snapshot Visualizer | Used for [Heap Snapshot visualizer extension for DevTools](https://learn.microsoft.com/microsoft-edge/devtools/whats-new/2023/01/devtools-109#heap-snapshot-visualizer-extension-for-devtools) in _What's New in DevTools (Microsoft Edge 109)_. | [/heap-snapshot-visualizer/](https://github.com/MicrosoftEdge/Demos/tree/main/heap-snapshot-visualizer) | n/a |
| Highlight pseudo-elements | Used for [View inherited highlight pseudo-elements](https://learn.microsoft.com/microsoft-edge/devtools/css/reference#view-inherited-highlight-pseudo-elements) in _CSS features reference_. | [/highlight-pseudo-elements/](https://github.com/MicrosoftEdge/Demos/tree/main/highlight-pseudo-elements/) | [Highlight pseudo-elements](https://microsoftedge.github.io/Demos/highlight-pseudo-elements/) demo |
| Idle detection | Used for [Emulate idle detector state](https://learn.microsoft.com/microsoft-edge/devtools/sensors/#emulate-idle-detector-state) in _Emulate device sensors_. | [/idle-detection/](https://github.com/MicrosoftEdge/Demos/tree/main/idle-detection) | [Idle detection demo](https://microsoftedge.github.io/Demos/idle-detection/) |
| JSON dummy data | Simple JSON files. Used for [View a JSON file or server response with formatting](https://learn.microsoft.com/microsoft-edge/web-platform/json-viewer). | [/json-dummy-data/](https://github.com/MicrosoftEdge/Demos/tree/main/json-dummy-data) | [JSON dummy data](https://microsoftedge.github.io/Demos/json-dummy-data/) (Readme) |
| Inspect Network Activity | Used for [Inspect network activity](https://learn.microsoft.com/microsoft-edge/devtools/network/). | [/network-tutorial/](https://github.com/MicrosoftEdge/Demos/tree/main/network-tutorial) | [Inspect Network Activity demo](https://microsoftedge.github.io/Demos/network-tutorial/) |
| Network tool reference | Used for [Network features reference](https://learn.microsoft.com/microsoft-edge/devtools/network/reference). | [/devtools-network-reference/](https://github.com/MicrosoftEdge/Demos/tree/main/devtools-network-reference) | [Network tool reference demo](https://microsoftedge.github.io/Demos/devtools-network-reference/) |
| Photo gallery | Used for [View your custom data in the performance profile](https://learn.microsoft.com/microsoft-edge/devtools/performance/extension#view-your-custom-data-in-the-performance-profile) in _Customize performance profile with extensibility APIs_, and [The truth about CSS selector performance](https://blogs.windows.com/msedgedev/2023/01/17/the-truth-about-css-selector-performance/). | [/photo-gallery/](https://github.com/MicrosoftEdge/Demos/tree/main/photo-gallery) | [Photo Gallery](https://microsoftedge.github.io/Demos/photo-gallery/) demo |
| Slow Calendar | Simple calendar demo app to test DevTools features such as the **Performance** tool and source map support. Used for [Added source map support in the Coverage tool](https://learn.microsoft.com/microsoft-edge/devtools/whats-new/2024/01/devtools-121#added-source-map-support-in-the-coverage-tool) in _What's New in DevTools (Microsoft Edge 121)_. | [/slow-calendar/](https://github.com/MicrosoftEdge/Demos/tree/main/slow-calendar) | [Slow Calendar](https://microsoftedge.github.io/Demos/slow-calendar/public/) demo |
| Margie's Travel | Demonstrates how to optimize a webpage's resources to make it load, appear, and be interactive faster. Used for [Optimize website speed using Lighthouse](https://learn.microsoft.com/microsoft-edge/devtools/speed/get-started). | [/travel-site/](https://github.com/MicrosoftEdge/Demos/tree/main/travel-site) | [Margie's Travel](https://microsoftedge.github.io/Demos/travel-site/) demo |
| Workspaces | Used for [Edit and save files in a workspace (Sources tool Workspace tab)](https://learn.microsoft.com/microsoft-edge/devtools/workspaces/). | [/workspaces/](https://github.com/MicrosoftEdge/Demos/tree/main/workspaces) | [DevTools Workspaces demo](https://microsoftedge.github.io/Demos/workspaces/) |
| Idle detection | Used for [Emulate idle detector state](https://learn.microsoft.com/microsoft-edge/devtools/sensors/#emulate-idle-detector-state) in _Emulate device sensors_. | [/idle-detection/](https://github.com/MicrosoftEdge/Demos/tree/main/idle-detection) | [Idle detection demo](https://microsoftedge.github.io/Demos/idle-detection/) |
<!-- "JSON dummy data" row is in DevTools & Cross-browser tables -->

See also:
Expand Down
5 changes: 5 additions & 0 deletions at-rules-font-palette-values/README.md
Original file line number Diff line number Diff line change
@@ -0,0 +1,5 @@
# View `@font-palette-values` CSS at-rules

➡️ Open the demo: **[View `@font-palette-values` at-rules](https://microsoftedge.github.io/Demos/at-rules-font-palette-values/)** ⬅️

For instructions, see [View `@font-palette-values` at-rules](https://learn.microsoft.com/microsoft-edge/devtools/css/reference#view-font-palette-values-at-rules) in _CSS features reference_.
17 changes: 17 additions & 0 deletions at-rules-font-palette-values/index.html
Original file line number Diff line number Diff line change
@@ -0,0 +1,17 @@
<!DOCTYPE html>
<html lang="en">

<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<link rel="icon" type="image/png" href="https://edgestatic.azureedge.net/welcome/static/favicon.png">
<title>View `@font-palette-values` at-rules</title>
<link rel="stylesheet" href="styles.css">
</head>

<body>
<p>old colors</p>
<p class="new">new colors</p>
</body>

</html>
17 changes: 17 additions & 0 deletions at-rules-font-palette-values/styles.css
Original file line number Diff line number Diff line change
@@ -0,0 +1,17 @@
@import url(https://fonts.googleapis.com/css2?family=Foldit:wght@700);

p {
font-family: 'Foldit';
font-size: 2rem;
}

@font-palette-values --New {
font-family: 'Foldit';
override-colors:
0 gold,
1 red;
}

.new {
font-palette: --New;
}
5 changes: 5 additions & 0 deletions at-rules-position-try/README.md
Original file line number Diff line number Diff line change
@@ -0,0 +1,5 @@
# View `@position-try` CSS at-rules

➡️ Open the demo: **[View `@position-try` at-rules](https://microsoftedge.github.io/Demos/at-rules-position-try/)** ⬅️

For instructions, see [View `@position-try` at-rules](https://learn.microsoft.com/microsoft-edge/devtools/css/reference#view-position-try-at-rules) in _CSS features reference_.
Comment thread
mikehoffms marked this conversation as resolved.
31 changes: 31 additions & 0 deletions at-rules-position-try/index.html
Original file line number Diff line number Diff line change
@@ -0,0 +1,31 @@
<!DOCTYPE html>
<html lang="en">

<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<link rel="icon" type="image/png" href="https://edgestatic.azureedge.net/welcome/static/favicon.png">
<title>View `@position-try` at-rules</title>
<link rel="stylesheet" href="styles.css">
</head>

<body>
<button popovertarget="menu" id="menu-btn">Your Account</button>

<ul role="nav" id="menu" popover>
<li><a href="#">View Profile</a></li>
<li><a href="#">Messages</a></li>
<li><a href="#">Favorites</a></li>
<li><a href="#">Account Settings</a></li>
<li>
<button popovertarget="submenu">Storefront <span class="arrow">➤</span></button>
<ul id="submenu" role="nav" popover>
<li><a href="#">Listings</a></li>
<li><a href="#">Special Offers</a></li>
<li><a href="#">Sign out</a></li>
</ul>
</li>
</ul>
</body>

</html>
100 changes: 100 additions & 0 deletions at-rules-position-try/styles.css
Original file line number Diff line number Diff line change
@@ -0,0 +1,100 @@
/* anchoring */
[popovertarget="menu"] {
anchor-name: --menu;
}

[popovertarget="submenu"] {
anchor-name: --submenu;
}

#menu {
position: absolute;
margin: 0;
position-anchor: --menu;
left: anchor(--menu left);
top: anchor(--menu bottom);
}

#submenu {
position: absolute;
margin: 0;
position-anchor: --submenu;
left: anchor(--submenu right);
top: anchor(--submenu top);
margin-left: var(--padding);
position-try-fallbacks: --bottom;
transition: left 0.25s, top 0.25s;
width: max-content;
}

@position-try --bottom {
margin: var(--padding) 0 0 var(--padding);
left: anchor(--submenu left);
top: anchor(--submenu bottom);
margin-left: var(--padding);
}

[popovertarget="submenu"] {
width: 100%;
display: flex;
justify-content: space-between;
}

/* animating */

/* etc */
:root {
--padding: 1rem;
}

#menu,
#submenu {
padding: var(--padding);
background: skyblue;
gap: 1rem;
border: none;
}

#menu:popover-open,
#submenu:popover-open {
display: grid;
}

#menu-btn {
background: royalblue;
color: white;
padding: var(--padding);
}

#submenu {
background: lightblue;
}

li {
list-style: none;
padding: 0;
}

a,
button {
font-family: system-ui;
text-decoration: none;
font-size: 1rem;
padding: 0;
color: black;
text-transform: uppercase;
font-weight: 700;
letter-spacing: 0.2px;
border: none;
background: none;
}

.arrow {
transition: rotate 0.2s;
}

#menu:has(:popover-open) {
.arrow {
rotate: -90deg;
}
}
5 changes: 5 additions & 0 deletions at-rules-property/README.md
Original file line number Diff line number Diff line change
@@ -0,0 +1,5 @@
# View `@property` CSS at-rules

➡️ Open the demo: **[View `@property` at-rules](https://microsoftedge.github.io/Demos/at-rules-property/)** ⬅️

For instructions, see [View `@property` at-rules](https://learn.microsoft.com/microsoft-edge/devtools/css/reference#view-property-at-rules) in _CSS features reference_.
20 changes: 20 additions & 0 deletions at-rules-property/index.html
Original file line number Diff line number Diff line change
@@ -0,0 +1,20 @@
<!DOCTYPE html>
<html lang="en">

<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<link rel="icon" type="image/png" href="https://edgestatic.azureedge.net/welcome/static/favicon.png">
<title>View `@property` at-rules</title>
<link rel="stylesheet" href="styles.css">
</head>

<body>
<ol>
<li class="one">Item one</li>
<li class="two">Item two</li>
<li class="three">Item three</li>
</ol>
</body>

</html>
33 changes: 33 additions & 0 deletions at-rules-property/styles.css
Original file line number Diff line number Diff line change
@@ -0,0 +1,33 @@
@property --itemSize {
syntax: "<length> | <percentage>";
inherits: true;
initial-value: 200px;
}

@property --borderWidth {
syntax: "<length>";
inherits: false;
initial-value: 10px;
}

ol {
--itemSize: 100px;
--borderWidth: 1px;
}

.two {
--itemSize: initial;
--borderWidth: inherit;
}

.three {
Comment thread
captainbrosset marked this conversation as resolved.
--itemSize: large;
--borderWidth: 3%;
}

li {
width: var(--itemSize);
border: var(--borderWidth) solid red;
background-color: yellow;
margin-bottom: 10px;
}
5 changes: 5 additions & 0 deletions at-rules-scope/README.md
Original file line number Diff line number Diff line change
@@ -0,0 +1,5 @@
# View `@scope` CSS at-rules

➡️ Open the demo: **[View `@scope` at-rules](https://microsoftedge.github.io/Demos/at-rules-scope/)** ⬅️

For instructions, see [View `@scope` at-rules](https://learn.microsoft.com/microsoft-edge/devtools/css/reference#view-scope-at-rules) in _CSS features reference_.
19 changes: 19 additions & 0 deletions at-rules-scope/index.html
Original file line number Diff line number Diff line change
@@ -0,0 +1,19 @@
<!DOCTYPE html>
<html lang="en">

<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<link rel="icon" type="image/png" href="https://edgestatic.azureedge.net/welcome/static/favicon.png">
<title>View `@scope` at-rules</title>
<link rel="stylesheet" href="styles.css">
</head>

<body>
<p>I'm just a piece of text.</p>
<div class="card">
<p>I'm the text that lives on a card.</p>
</div>
</body>

</html>
Loading