Alt tags

Alt tags, short for “alternative text”, are HTML attributes that are used to provide text descriptions for images on web pages. These texts are particularly important as they are used by search engines to understand the content of images and improve accessibility by being read aloud by screen readers to people with visual impairments.


Importance of alt tags for search engine optimization

Alt tags contribute significantly to search engine optimization (SEO). By precisely describing the image content in an alt tag, webmasters improve the findability of their content in search engines. Search engines such as Google use these tags to understand the context of images and offer relevant results in the image search. This is why they are a crucial aspect of on-page optimization.


Target group and intended use of alt tags

Alt tags serve two main target groups: Users who rely on screen readers due to visual impairments, and the search engines that evaluate content for indexing.


  • Accessibility: Enables blind and visually impaired users to access visual information.
  • SEO: Supports search engines in recognizing images and improves the visibility of websites.

But how should alt tags be designed?


Best practices for alt tags

Creating effective alt tags requires an understanding of how they can improve both accessibility and search engine optimization (SEO ). Here are some best practices to make sure your alt tags are doing their job.


Integrate relevant information into alt tags

Alt tags should be precise and descriptive to convey the content and function of the image on the website. Here are some guidelines:


  • Contextual: The alt text should be related to the surrounding text and the purpose of the image within the content.
  • Informative: For images that carry information, such as infographics, the alt text should reflect this information as well as possible.


Length restrictions and sensible design of alt tags

While it is important to create informative alt texts, it is also important to keep their length appropriate:

  • Maximum length: A good guideline is to keep the alt text under 125 characters to ensure compatibility with most screen readers.
  • Concentrate on the essentials: Focus on the most important information or emotions that the image conveys.


Avoiding keyword stuffing in alt tags

It’s crucial to keep the alt text natural and not try to overload it with keywords to improve rankings. This can have a negative impact on SEO and affect the user experience.


  • Natural language: Write as if you were describing the picture to someone who cannot see it.
  • Relevant keywords: Integrate keywords sensibly and only if they fit naturally into the description.


Table: Best practices for alt tags

Guideline Description
Contextuality The alt text should be relevant to the surrounding content and the purpose of the image.
Information content In the case of informative images, the alt text should reflect the central information.
Length restriction Ideally, keep the alt text under 125 characters.
Avoidance of keyword stuffing Use keywords naturally and only if they contribute to the description.

Alt tags and SEO

Alt tags have a direct impact on search engine optimization (SEO) and can significantly improve the visibility of a website in search results. The correct use of alt tags helps search engines to understand the content of images and place them accordingly in the search results.


Effects of alt tags on the image search

Alt tags are particularly important for image searches as they provide search engines with context and descriptions of the images. Images with well-worded alt tags have a higher chance of appearing in image search results, which can lead to more traffic to the website.


  • Visibility in the image search: A clear and precise description helps to increase the relevance of the image for certain search queries.
  • Improved ranking: Images with well-optimized alt tags can rank higher in search results.


Optimization of alt tags for search engines

To use alt tags effectively for SEO, they should contain relevant keywords that reflect both the content of the image and the context on the page. It is important to maintain a balance and avoid keyword stuffing.

  • Relevant keywords: Integrate keywords that are relevant to the image and the surrounding content.
  • Naturalness: Avoid overloading alt texts with keywords to avoid a penalty from search engines.


Importance of meaningful alt tags for the overall optimization of a website

Meaningful alt tags not only contribute to the image search, but also support the general SEO strategy of a website. They improve accessibility, which is seen by search engines as a positive factor for the ranking.


  • User experience: An improved user experience can lead to longer visit times and a lower bounce rate.
  • Content understanding: Helps search engines to better understand the context and relevance of the website.


Table: Optimization of alt tags for SEO

Aspect Tips
Keywords Integrate relevant keywords naturally into the alt text.
Length Keep the alt text short and concise, ideally under 125 characters.
Description Make sure that the alt text accurately describes the content of the image.
Avoidance of keyword stuffing Avoid overloading with keywords to avoid penalties.


Alt tags in different contexts

The use and meaning of alt tags varies depending on the context. In e-commerce websites, editorial content and on social media, alt tags play a crucial role in accessibility, user experience and SEO.

But in what way?


E-commerce and the importance of meaningful product image alt tags

Meaningful alt tags for product images are essential on e-commerce websites. Not only do they contribute to SEO by ensuring that products can be found in image searches, but they also improve accessibility for users who rely on screen readers.

They are used for the:

  • Product discovery: Improves the findability of products in the image search.
  • Customer loyalty: Increases accessibility and supports a positive shopping experience for all users.


Alt tags in blog posts and editorial content

For blog posts and editorial content, alt tags offer the opportunity to explain the context of images and increase the relevance of the text for search engines. They contribute to the overall story and can increase reader loyalty.


  • Storytelling: Supports visual storytelling through additional image descriptions.
  • SEO value: Improves the SEO of articles and posts through context-related keywords.


Social media and the use of alt tags for accessible content

The importance of alt tags for accessibility is also being increasingly recognized on social media platforms. By providing alt tags for images, content can be made accessible to a wider audience.


  • Inclusivity: Extends the reach of posts by making them accessible to users with visual impairments.
  • Engagement: Can increase engagement by making content understandable to a wider audience.


Table: Application of Alt tags by context

Context Meaning
E-Commerce Improving product discovery and customer loyalty
Blogposts Support for storytelling and SEO
Social media Promoting inclusivity and commitment

Tools for checking and optimizing alt tags

Checking and optimizing alt tags is an important step in improving the accessibility and SEO of a website. Fortunately, there are a number of tools that can help to effectively analyze and optimize alt tags.


Relevant Tools for analyzing and optimizing alt tags

There are various tools that have been specially developed to check the use of alt tags on websites and provide suggestions for improvements. Some of these tools include:


  • WAVE (Web Accessibility Evaluation Tool): A free tool that provides a visual representation of a website’s accessibility issues, including missing or inadequate alt tags.
  • Axe Accessibility Checker: A browser extension that enables a comprehensive check of the accessibility of web content, including the analysis of alt tags.
  • Google Lighthouse: An automated tool that is part of Chrome Developer Tools and generates reports on performance, accessibility, progressive web apps and more, including alt tag checks.


Possible applications and advantages of tools for alt tags

These tools offer various functions that address specific aspects of alt tag usage:


  • Identification of missing alt tags: Helps to recognize images that are missing alt tags, which is a fundamental accessibility problem.
  • Evaluate the quality of alt tags: Analyze the quality of existing alt tags and make recommendations for improvements.
  • Suggestions for improvement: Offer specific suggestions on how alt tags can be optimized to improve both accessibility and SEO.


Table: Tools for checking and optimizing alt tags

Tool Functions Advantage
WAVE Visual accessibility analysis, identification of missing alt tags Simplicity and directness
Axe Accessibility Checker Comprehensive accessibility check, including alt tags Detailed reports and recommendations
Google Lighthouse Performance and accessibility reports, Alt-Tag tests Integration in Chrome Developer Tools, comprehensiveness


Alt tags are a critical factor for SEO as they help search engines understand the content of images and rank them accordingly in search results. They make a significant contribution to increasing the visibility of a website in the image search and can improve the overall SEO performance of a website.

The importance of alt tags is expected to continue to grow, particularly in light of the ongoing development of web accessibility and artificial intelligence (AI) technologies that could further improve the creation and analysis of alt text. It’s important that webmasters and content creators stay up to date and adopt best practices for creating alt tags to make their websites accessible and findable for all users.