Writing alt text with AI

"Writing text for images to make them accessible to screen readers can often feel like a chore, especially when dealing with a large number of visuals to describe. Unlike other writing tasks, alt text demands a unique description for each image with attention to content and context. This process can feel repetitive or time-consuming, as if it is something additional to the task at hand."

"Full disclosure: I am guilty of writing horrible alternative text like this for the image below, either out of expediency or pure laziness. Main hall of Union Station in Washington, D.C.Commit this image to memory because we're going to use it for the rest of this post. We're going to try several iterations of our prompt and see what we get back. Each prompt and subsequent response is copied and pasted verbatim. For my LLM, I am using Claude Sonnet 4."

"This image shows the magnificent main hall of Union Station in Washington, D.C. The photograph captures the building's stunning Beaux-Arts architecture, featuring a soaring barrel-vaulted ceiling adorned with an intricate coffered pattern. The ceiling is decorated with hundreds of octagonal coffers, each containing a golden rosette that creates a mesmerizing geometric pattern stretching across the vast space. The hall is characterized by its grand scale and classical proportions, with massive arched openings and columns supporting the structure."

Writing alt text for images to make them accessible to screen readers often feels like a chore, particularly when many visuals require description. Alt text requires unique, context-aware descriptions tailored to each image's content. The piece includes a first-person admission of producing poor alternative text from expediency or laziness. An image of Union Station's main hall in Washington, D.C. is used as a running example. Multiple prompt iterations are tested with an LLM (Claude Sonnet 4), copying prompts and responses verbatim. An initial poor prompt produced a long architectural description that emphasized scale and ornate details but ended abruptly.

Read at Jared Cunha