gistmag

GistMag Alt Text Generator helps you automatically generate high-quality alternative text for images in your WordPress media library.
It uses the GistMag API to create descriptive, SEO-friendly alt text that improves accessibility for screen readers and helps search engines better understand your images.
Key features:
<ul>
<li>Auto-generate alt text on image upload</li>
<li>Generate alt text manually for individual images</li>
<li>Bulk alt text generation for existing media library images</li>
<li>Multiple modes: Short, Long, and SEO-optimized alt text</li>
<li>Works in the Media Library list and grid views</li>
<li>Usage statistics so you can track how many images you’ve processed</li>
</ul>
You will need a free GistMag account and API key to use this plugin.

GistMag Alt Text Generator

AI-powered alt text generation for your WordPress media library. Improve accessibility and SEO with high-quality alternative text for images.

Connor Bulmer

AI Auto Alt Text Generator is a lightweight, privacy-conscious plugin that uses OpenAI vision-capable models (defaulting to GPT-4o mini, with GPT 5 Mini/Nano options) to create meaningful, screen-reader-friendly alt text and SEO-friendly titles for your images. Whether you add a single image, bulk-process your library, or just want a one-click fix in the Media Library, the plugin handles it all – no manual effort required.
This solution is far cheaper than many alternatives because it cuts out the middle-person. You’ll just need to bring your own OpenAI API key.
<h3>✨ Key features</h3>
<ul>
<li>Automatic alt text on upload – set-and-forget accessibility.</li>
<li>Optional automatic image titles – improve SEO with descriptive titles.</li>
<li>One-click manual generation – “Generate Alt Text & Title” button in the Media Library.</li>
<li>Bulk update tool – batch-process existing images (five at a time) with a configurable pause between batches.</li>
<li>Prompt fine-tuning – supply site-wide context and optionally include the image file name.</li>
<li>Model selection – choose GPT-4o mini (default) or GPT 5 Mini/Nano (BETA).</li>
<li>Image size & detail control – choose the resolution and level of visual detail sent.</li>
<li>No extra servers – data flows only between your site and OpenAI; nothing is stored off-site.</li>
<li>Multilingual output – choose English (UK), English (US) or other popular languages. (English US is the default.)</li>
</ul>
<h3>🧭 Where to find the bulk tool</h3>
<ul>
<li>Tools → Bulk Alt Text Update</li>
<li>Media → Bulk Alt Text Update (shortcut that redirects to the Tools page)</li>
<li>Settings → Alt Text Generator includes a button linking straight to the bulk page</li>
</ul>
<h3>🧠 How it works</h3>
<ol>
<li>When an image is uploaded (or manually chosen), the plugin creates a temporary public URL for that image.</li>
<li>It sends the image – plus optional context such as the parent post title, your custom site context and the file name – to your selected OpenAI vision model.</li>
<li>OpenAI returns a concise description.
<ul>
<li>Alt text is stored in WordPress’ native <code>_wp_attachment_image_alt</code> field. </li>
<li>(Optional) The returned title is stored as the attachment post title.</li>
</ul>
</li>
<li>Nothing is cached or stored on OpenAI’s side; only the final strings live in your database.</li>
</ol>
<h3>Settings overview</h3>
<ul>
<li>OpenAI API Key – Required to connect to GPT-4o. </li>
<li>OpenAI Model – GPT-4o mini (default), GPT 5 Mini (BETA), or GPT 5 Nano (BETA). </li>
<li>Image Size to Send – Thumbnail, Medium, Large, or Full. </li>
<li>Image Detail Quality – ‘Low’ or ‘High’ (Low uses fewer tokens). </li>
<li>Bulk batch size – Number of images per batch (lower values reduce rate-limit risk). </li>
<li>Site Context – Optional free-form prompt guidance (brand voice, niche, etc.). </li>
<li>Send Image File Name – Include file name in the prompt for extra context. </li>
<li>Automatically Generate Title – Add descriptive titles alongside alt text. </li>
<li>Use full context for image titles – When enabled, title generation includes site context and file name (uses more tokens). </li>
<li>Bulk optimiser delay (seconds) – Pause between batches during bulk runs. </li>
<li>OpenAI request timeout (seconds) – Max wait time for OpenAI responses (10–120s) to reduce timeout failures on slower hosts. </li>
<li>Output Language – Default English (US). Choose English (UK) for British spellings or another popular language; outputs (alt text and titles) will be generated in the selected language.</li>
</ul>
<h3>External services</h3>
This plugin connects to the OpenAI API to generate alt text and (optionally) image titles.
<ul>
<li>Endpoint: <code>https://api.openai.com/v1/chat/completions</code> </li>
<li>When called:
<ul>
<li>On image upload (automatic) </li>
<li>Via “Generate Alt Text & Title” button in Media Library (manual) </li>
<li>Via Tools → Bulk Alt Text Update (bulk) </li>
</ul>
</li>
<li>Data sent: image URL, optional file name, optional site context, optional parent post title </li>
<li>Terms: <a href="https://openai.com/policies/terms-of-use" rel="nofollow ugc">https://openai.com/policies/terms-of-use</a> </li>
<li>Privacy: <a href="https://openai.com/policies/privacy-policy" rel="nofollow ugc">https://openai.com/policies/privacy-policy</a></li>
</ul>

AI Auto Alt Text Generator

Automatically generates alt text and image titles for your WordPress media uploads with selectable OpenAI models (defaulting to GPT-4o mini), improvin …

GistMag Alt Text Generator vs AI Auto Alt Text Generator