HTML <bdo> Tag

The HTML <bdo> tag is used for over-riding the text direction in an HTML document.

This can be useful when displaying right-to-left written text (such as Hebrew, Arabic, Persian, Thaana, Urdu and other languages/scripts that are written from right to left) within left-to-right text (such as English) or vice versa.


The <bdo> tag is written as <bdo dir=""></bdo> with the relevant text inserted between the start and end tag. The value of the dir attribute must be either rtl or ltr (but not auto, which is allowed in other elements).

Like this:


Basic tag usage

Here's an example using English words written backwards to demonstrate how the tag works.

Persian Example

Here's an example using Persian (a right-to-left language). The first line doesn't use the <bdo> tag to specify right-to-left text, while the second one does. You can see that by adding <bdo dir="rtl">, the exclamation mark appears to the left of the phrase.

If the exclamation mark is part of the right-to-left phrase, it should appear to the left of it.


Attributes can be added to an HTML element to provide more information about how the element should appear or behave.

The <bdo> element accepts the following attributes.

dir** Although this element has no local attributes, you must use the dir global attribute. The dir attribute specifies the direction of the text:
  • ltr: Left to right
  • rtl: Right to left

This attribute must have the value ltr to specify a left-to-right override and with the value rtl to specify a right-to-left override.

Global Attributes

The following attributes are standard across all HTML elements. Therefore, you can use these attributes with the <bdo> tag , as well as with all other HTML tags.

For a full explanation of these attributes, see HTML 5 global attributes.

Event Handlers

Event handler content attributes enable you to invoke a script from within your HTML. The script is invoked when a certain "event" occurs. Each event handler content attribute deals with a different event.

Most event handler content attributes can be used on all HTML elements, but some event handlers have specific rules around when they can be used and which elements they are applicable to.

For more detail, see HTML event handler content attributes.