HTML <bdi> Tag
What is the <bdi> Tag?
When you work with multilingual content involving RTL (right-to-left) languages like Arabic or Hebrew, and LTR (left-to-right) languages like English or French, improper management of directionality can cause problems with text and fonts. This is where the <bdi> tag steps in. It helps resolve such issues by isolating a specific chunk of text from its surrounding environment, telling the browser that this isolated section should follow its own directional rules—independently from the rest of the text.
In simpler terms, if you’re mixing English with a number written in Arabic or displaying a price in a right-to-left context, the <bdi> tag ensures that the isolated portion of the text (like the price or the number) maintains its correct layout, without being affected by the surrounding language’s direction.
How does the <bdi> Tag Work?
The browser sometimes mixes up the rendering of certain parts when you combine left-to-right and right-to-left text on a webpage, especially with dynamic content like numbers, prices, or symbols. For example, if an English sentence includes a number written in Arabic, the browser may try to display that number in reverse order, which can break the layout and make the content look jumbled.
This is where the <bdi> tag comes into play. It isolates the content inside it and directs the browser to apply the correct directionality to that piece of text, preventing the surrounding content from influencing it. It’s like saying, “Hey, browser, handle this section on its own—don’t let the surrounding text interfere with its formatting.”
Why would you use the <bdi> Tag?
You might wonder why this tag is necessary in the first place. Here are the key reasons:
- Protects dynamic or mixed-direction content: If you’re showing numbers, prices, or user-generated content that can be in a different language or script, the
<bdi>tag ensures the content is correctly displayed. Whether it’s a right-to-left number in the middle of an English sentence or a price in Arabic, the<bdi>tag makes sure it stays in the proper format. - Prevents directionality conflicts: Without the
<bdi>tag, text in an RTL language could affect the formatting of surrounding text in an LTR language (or vice versa). This tag prevents that from happening by creating an isolated zone for the text inside it. - Helps with multilingual websites: If you’re developing a multilingual website that supports both LTR and RTL languages, the
<bdi>tag becomes a helpful tool to ensure your site looks great and functions properly regardless of the language or script being used.
What to Keep in Mind about the <bdi> Tag?
While the <bdi> tag is a great tool in specific cases, there are a few things you should keep in mind when using it:
- It’s only for directional issues: The
<bdi>tag doesn’t change the language of the content inside it. It doesn’t affect the styling or appearance of the text—it just isolates it so the browser knows how to apply the correct text direction. - It’s for isolated sections: You should only use the
<bdi>tag for content that could potentially conflict with the directionality of surrounding text. It’s not necessary for regular text where the language or directionality is consistent. - CSS still works: If you want to style the text inside the
<bdi>tag (for example, changing its color or font), you’ll need to use CSS for that. The<bdi>tag itself only manages directionality—it doesn’t apply any visual styles.
An Example of the <bdi> Tag in Action
Here’s a real-world example of how the <bdi> tag can be used to prevent directionality issues in mixed-language content:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Bidi Example</title>
</head>
<body>
<p>Our special offer: <bdi>₪100</bdi> for this amazing product!</p>
</body>
</html>
In this example:
- You have an English sentence with a price written in Israeli Shekels (₪).
- The
<bdi>tag ensures that the price₪100is displayed correctly without being affected by the surrounding English text. A right-to-left context (such as Arabic) might reverse or misalign the number without the tag.
This is a great example of how the <bdi> tag isolates the price, ensuring the number is displayed properly regardless of the surrounding text’s directionality.
Why shouldn’t you use the <bdi> Tag All the Time?
While the <bdi> tag is powerful, it’s important not to overuse it. Here are some reasons why:
- Not necessary for static content: If your page only contains left-to-right content (like an all-English page), there’s no need to use the
<bdi>tag. It’s only necessary when you’re dealing with mixed-direction content or dynamic content that may change direction. - Can add unnecessary complexity: Applying the
<bdi>tag to every section of text on your page could make your HTML more complicated than it needs to be. Only use it when the directionality issue arises. - Browser support: While modern browsers support the
<bdi>tag, always make sure to check compatibility if you’re working with older browsers. However, it’s safe to say that the majority of modern browsers handle this tag well.
When should you use the <bdi> Tag?
You should use the <bdi> tag when:
- You’re mixing right-to-left and left-to-right content: If your webpage contains both RTL and LTR content and needs to display dynamic or mixed-direction text (like numbers or prices), the
<bdi>tag will keep things looking correct. - You have dynamic content that might cause issues: If you’re displaying dynamic values—such as user input or data pulled from a database—where the directionality could be inconsistent, the
<bdi>tag will ensure that the content remains properly formatted. - You’re designing multilingual websites: For multilingual sites that support RTL languages like Arabic or Hebrew, the
<bdi>tag can help prevent problems with text direction, making sure your content looks consistent across all languages.
In Conclusion
The <bdi> tag is a powerful tool for dealing with text directionality issues on multilingual websites. It helps ensure that mixed-direction content, like numbers or prices, displays correctly even when other text with different directionality surrounds it.By isolating the content, the <bdi> tag gives you control over how the browser handles it, making it a valuable addition when dealing with dynamic or multilingual content