# Browser Compatibility

XCover Elements (XCE) requires modern browser features to deliver a robust web component experience. This page provides a comprehensive reference for browser compatibility requirements and supported platforms.

**Global Coverage:** 93% of worldwide browser usage is supported.

### Methodology & Sources

Browser compatibility data is derived from authoritative sources and feature-level checks:

* [**Can I use**](https://caniuse.com/) - Support tables for HTML5, CSS3, and modern web features
* [**MDN Web Docs**](https://developer.mozilla.org/) - Comprehensive browser compatibility documentation
* [**WebKit Release Notes**](https://webkit.org/) - Safari-specific feature tracking

Where possible, compatibility is determined through **feature-level checks** rather than browser versions alone. Key features monitored include:

* `fetch` API
* Custom Elements (Web Components)
* Shadow DOM
* CSS Nesting
* ES2022+ JavaScript features

### Required Browser Features

XCover Elements depends on the following modern web platform features:

| Feature                                     | Usage in XCE                                                             | Browsers Lacking Support                                          |
| ------------------------------------------- | ------------------------------------------------------------------------ | ----------------------------------------------------------------- |
| **Custom Elements & Shadow DOM**            | Core architecture for encapsulated UI components and custom elements     | IE (all versions), Opera Mini, older Android browsers, UC Browser |
| **CSS Nesting**                             | CSS Modules with nested selectors for concise, modular component styling | Safari < 17, older Firefox versions, legacy mobile browsers       |
| **Numeric Separators & Logical Assignment** | Cleaner numeric literals and compact syntax (ES2022)                     | Browsers without ES2022 support                                   |
| **Optional Chaining & Nullish Coalescing**  | Helper functions and optional prop handling (ES2020)                     | Very old browsers pre-ES2020                                      |
| **CSS Container Queries**                   | Responsive component behavior without media query boilerplate            | Not fully supported in older browsers                             |
| **ES Modules Dynamic Import**               | Code splitting and lazy loading for optimized bundle sizes               | IE, legacy browsers                                               |

### Supported Browsers

#### Desktop Browsers

| Browser                | Minimum Version | Release Date   | Notes                   |
| ---------------------- | --------------- | -------------- | ----------------------- |
| **Chrome**             | 120+            | November 2023  | **Recommended browser** |
| **Mozilla Firefox**    | 117+            | August 2023    | Full feature support    |
| **Safari**             | 17+             | September 2023 | macOS and iOS           |
| **Microsoft Edge**     | 120+            | November 2023  | Chromium-based          |
| **Opera**              | 106+            | November 2023  | Chromium-based          |
| **Brave**              | 1.61+           | November 2023  | Chromium-based          |
| **Vivaldi**            | Chromium 120+   | 2023+          | Chromium-based          |
| **Arc Browser**        | Chromium 120+   | 2023+          | Chromium-based          |
| **DuckDuckGo Browser** | Chromium 120+   | 2023           | Chromium-based          |
| **Yandex Browser**     | Chromium 120+   | 2023+          | Chromium-based          |
| **SRWare Iron**        | Chromium 120+   | 2023+          | Chromium-based          |

#### Regional & Specialized Browsers

| Browser                  | Minimum Version | Release Date | Notes                      |
| ------------------------ | --------------- | ------------ | -------------------------- |
| **ChatGPT Atlas**        | Chromium 120+   | October 2025 | Chromium-based, macOS only |
| **Samsung Internet**     | Latest stable   | -            | Chromium-based             |
| **QQ Browser** (Tencent) | Chromium 120+   | -            | Chromium-based             |
| **Baidu Browser**        | Chromium 120+   | -            | Chromium-based             |

#### Mobile Browsers

| Platform    | Browser          | Minimum Version | Support Level |
| ----------- | ---------------- | --------------- | ------------- |
| **iOS**     | Safari           | 17+             | Full          |
| **iOS**     | Chrome           | 120+            | Full          |
| **iOS**     | DuckDuckGo       | Latest          | Full          |
| **Android** | Chrome           | 120+            | Full          |
| **Android** | Firefox          | 117+            | Full          |
| **Android** | Samsung Internet | Latest          | Full          |
| **Android** | DuckDuckGo       | Latest          | Full          |

***

### Unsupported Browsers

The following browsers **do not support** XCover Elements:

| Browser               | Status         | Reason                                                   |
| --------------------- | -------------- | -------------------------------------------------------- |
| **Internet Explorer** | ❌ All versions | End of Life; lacks Web Components, modern JS/CSS support |
| **Chrome**            | ❌ < 120        | Missing ES2022 support and modern APIs                   |
| **Firefox**           | ❌ < 117        | Missing modern CSS features and JS support               |
| **Safari**            | ❌ < 17         | Missing CSS nesting support and WebKit features          |
| **Edge Legacy**       | ❌ All versions | Replaced by Chromium-based Edge                          |
| **Opera**             | ❌ < 106        | Missing ES2022 support                                   |
| **Opera Mini**        | ❌ All versions | Does not support Web Components; outdated JS engine      |
| **UC Browser**        | ❌ < 2023       | Missing Web Components, CSS nesting, ES2022 support      |
| **KaiOS Browser**     | ❌ All versions | Missing ES2022 support                                   |


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