Screen readers are software applications designed for people who are blind or have low vision.
Their purpose is to deliver the information displayed on websites and apps through an alternative channel — bypassing the visual barrier caused by a user's disability — so that they can browse websites and apps and enjoy everything on them just like any other user.
Screen readers rely on technology that converts displayed text into audio, allowing users who consume content on websites or apps to hear the information and access written text in exactly the same way as any sighted user.
How Do Screen Readers Work?
Screen readers parse the content displayed on screen and convert it into speech.
They offer a wide range of functions for reading content — from text paragraphs on the screen, to recognizing links and buttons, to describing images based on their ALT tags (alternative text).
For efficient navigation, a screen reader maps the text to the visual information (images, links), so that users can understand the structure of a website or app in a logical way. Everything we take in visually, a screen reader user hears in exactly the same intuitive order that our eyes move from element to element on the screen.
Let's Take a Closer Look at ALT Tags
One of the most important elements for screen readers is the ALT tag.
ALT tags (also known as alternative text or alt text) are used to describe images and other visual elements — such as buttons or graphics — where the text embedded in the code describes the visual content in a way that helps the user understand what is on the screen, even though they cannot see it.
For example, if there is an image of a cat, the alternative text tag could read: "Image of a cat." The screen reader will recognize this tag and describe the image to the user.
Through ALT tags, headings organized in a proper hierarchy (such as an H1 heading that signals the main title, H2 for subheadings, and so on), and other accessibility-supporting components, screen readers give users access to digital content and improve the overall experience for people with visual impairments.