CMLABS / SEO Terms What is Alt Tag?

The Definition of Alt Tag

Alt Text (Alternative text) called as "alt attributes" or technically called as "alt tag" is an HTML code used to describe a display and function of a picture on a website page.

The Benefits of Alt Tag

1. Adding alternative text to a photo or picture is the main principle of the accessibility on a certain web page. Disabled users who use screen reader will read alt attribute to understand more about the picture on a web page.
2. Alt Tag will be displayed as an alternative picture if the picture file cannot be loaded.
3. Alt tag gives a better context and description of a picture for crawler on search engines. It helps web owners to index pictures correctly.

Why is Alt Tag Important?

1. Accessibility

Alt Tag is a principle of web design, so it can be easily accessible. Its main objective is to describe a picture to users who have limited ability to see or identify pictures visually.

2. Image SEO

Using alternative text on picture not only can create a better experience for users, but also can help site owners to get the advantages of SEO explicitly or implicitly. With the implementation of image tittles and good file naming, alternative text on pictures can also contribute to SEO.

3. Raising Rank on Google Image

Google Image is the second biggest search engine in the world in which it is responsible for 20.45% online search that put it on higher position than YouTube, Bing, and other search engines. Adding alternative text on pictures is also helpful to raise rank on Google Image.

4. As an Anchor Text for Picture Link

Anchor Text refers to clickable words that connect one page to other pages. However, not all links can be in the form of texts, it can also be in the form of pictures. In using a picture as a link, alt tag would help Google to understand more about the linked page.

How to Write A Good Alt Tag

1. Explain the picture as specifically as possible

Alt tag was originally designed to give an explanation to a picture for users who are unable to see it. If a picture does not have meaning, and only has a design objective, set in CSS.

2. Make it (relatively) short

Screen reader is known for cutting alternative text around 125 characters, so it is better to make alternative text in a short amount of characters.

3. Use keywords

Alt tag provides another opportunity to add target keyword on pages, make search engines recommend the web of the owner because it is relevant to the specific search request.

4. Avoid Keyword Stuffing

Focus on writing the descriptive alternative text that give context to pictures, and if possible, include the target keyword.

5. Don't use picture as a text

Because search engines cannot read text in the form of pictures, owner has to avoid using pictures as alternative words. If you want to add, explain what described on photo in the alternative text.

6. Don't includes "image," "picture," and others in the description

It is assumed that alternative texts contain of description about pictures, so it is not necessary to specify it with the words "picture" or "image."

7. Don't forget longdesc = "".

Use longdesc tag = " " for more complex pictures that need to be described longer.

8. Don't ignore the form button

If a form in a website use a picture as the "send" button, give an alt attribute. Picture button must have alternative text attribute that describes the function of the button such as "search," "apply now," "sign up," and others.

Related Terms

Title Tag

Title tag is both significant and intention-grabbing element in SERP. Title tag has to fulfill a certain length.


Web crawler, spiders, or search engine bots are tasked to download and index content from all over the Internet.


Query is an ability to show data from database in the form of information that users want to write in a certain format.

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