The best alt text generators

Images are a powerful way to convey information, emotion, and stories on the web. However, for the visually impaired and other groups that rely on screen readers or text-based browsing, standard images can act as barriers to accessing content. This is where alt text, the textual alternative for visual elements, becomes essential. Well-written alt text provides descriptive summaries of images so those unable to see them can still understand the context and meaning. Creating good alt text can be challenging though. Thankfully, new technologies like AI image description tools, large language models like ChatGPT and alt text generators are making it easier to produce alt text that is both accurate and efficient. Let’s look at tips for crafting effective alt text both manually and with AI assistance. The goal is to demonstrate how these tools can make web content more universally accessible.

• Use an AI image description tool like Anthropic, Descript, or Microsoft Seeing AI to automatically generate alt text descriptions of images. These tools can analyze an image and describe its contents in a few sentences.

• Manually write descriptive alt text yourself. Focus on succinctly summarizing the main elements of the image rather than every single detail. Describe the purpose of the image, the relationships between elements, and any important text/symbols.

• Use an online alt text generator tool like WebAIM’s WAVE or accessiBe’s ai Altty. These allow you to upload an image and provide auto-generated alt text as a starting point, which you can then edit or customize.

• For complex images like charts/graphs, break down the key components in a structured way. Explain what the graphic shows overall, describe trends and relationships in the data, mention any important text labels, etc.

• Don’t overload the alt text with unnecessary information or keywords. Screen readers will read every word, so be concise. The alt text should serve as a textual equivalent of the image.

• Test the alt text by reading it out loud without the image for context. If it makes sense and conveys the purpose and content clearly, it’s good alt text.

• ChatGPT can provide decent alt text descriptions when prompted appropriately, but quality varies. Large language models like ChatGPT can summarize image contents based on training data. However, accuracy is not always reliable.

• Claude by Anthropic aims for truthfulness and factual accuracy as a fundamental principle. Early tests indicate Claude often outperforms ChatGPT for precise image descriptions suited for alt text.

• BARD is Google’s experimental conversational AI service launched to compete with ChatGPT. So far, limited details are available on BARD’s capabilities. It may have potential for alt text but needs more real-world testing.

• A key advantage of Claude and BARD is their focus on providing correct information verified against real-world knowledge. This makes them well-suited for generating alt text, which should describe images factually without hallucinating unverified details.

• ChatGPT and other large language models can give decent alt text results, but lack the rigor of knowledge-based AI systems like Claude specialized for precise and truthful image captioning.

• All AI alt text generators should be used thoughtfully, in combination with human review and editing. The AI provides a helpful starting point, but human judgment is still important for tweaking and optimizing alt text.

• No system is perfect; combining the strengths of different AI tools and manual efforts will likely produce the highest quality alt text with current technology. The space continues to evolve rapidly.

The most effective approach is often a combination of auto-generated suggestions to start, then refining and optimizing the alt text manually for the specific image. The goal is to make visual content understandable when heard rather than seen. When used appropriately in tandem, AI and humans can generate accurate, engaging alt text at scale.