# HTML longdesc Attribute
The `longdesc` attribute of the `` tag is used to provide a URL to a detailed, long description of an image. This is particularly useful for complex images, such as charts, graphs, or diagrams, where a simple `alt` text is insufficient to convey all the information.
---
## Definition and Usage
The `longdesc` attribute specifies the URL of a page or document that contains a long description of the image.
> **⚠️ Deprecation Warning:**
> **HTML5 does not support the `longdesc` attribute.**
> Due to extremely poor browser support and lack of visibility for sighted users, this attribute has been deprecated. It is highly recommended to use modern accessibility alternatives instead.
---
## Syntax
```html
```
### Attribute Values
| Value | Description |
| :--- | :--- |
| *URL* | The URL pointing to the page containing the image description.
**Possible values:** • **Absolute URL:** Points to another website (e.g., `longdesc="https://www.example.com/desc.txt"`) • **Relative URL:** Points to a file within the same website (e.g., `longdesc="description.txt"`) |
---
## Code Examples
### Basic Usage (Legacy)
In legacy systems, the `longdesc` attribute was implemented as follows:
```html
```
### Modern Alternatives (Recommended)
Since `longdesc` is obsolete and unsupported by almost all modern browsers, you should use one of the following accessible alternatives:
#### Option 1: Using a Standard Text Link (Best Practice)
The simplest and most accessible approach is to place a visible link to the description page directly below or near the image. This benefits all users, including those who are visually impaired.
```html
Figure 1: Sales Chart for Q4 2023.
View a detailed text description of this chart.
```
#### Option 2: Using WAI-ARIA Attributes (`aria-describedby`)
If the description is present on the same page, you can link the image to the description container using the `aria-describedby` attribute.
```html
This chart shows a 15% increase in sales during October, a steady plateau in November, and a peak of 45% growth in December 2023.
```
---
## Browser Support
| Chrome | Edge | Firefox | Safari | Opera |
| :---: | :---: | :---: | :---: | :---: |
| ❌ Not Supported | ❌ Not Supported | ❌ Not Supported | ❌ Not Supported | ❌ Not Supported |
Almost all modern mainstream browsers do not support or have dropped support for the `longdesc` attribute. Screen readers may still offer limited support, but relying on it is discouraged for modern web development.
YouTip
```
### Modern Alternatives (Recommended)
Since `longdesc` is obsolete and unsupported by almost all modern browsers, you should use one of the following accessible alternatives:
#### Option 1: Using a Standard Text Link (Best Practice)
The simplest and most accessible approach is to place a visible link to the description page directly below or near the image. This benefits all users, including those who are visually impaired.
```html