AI Auto Alt Text Generator vs AltTextLab AI Alt Text Generator

AI Auto Alt Text Generator is a lightweight, privacy-conscious plugin that uses OpenAI vision-capable models (defaulting to GPT-5.4 nano, with GPT-5.4 mini and legacy GPT-4o mini 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. ✨ Key features Automatic alt text on upload – set-and-forget accessibility. Optional automatic image titles – improve SEO with descriptive titles. One-click manual generation – “Generate Alt Text & Title” button in the Media Library. Bulk update tool – batch-process existing images, including those that only have filename-based alt text, with a configurable pause between batches. Prompt fine-tuning – supply site-wide context and optionally include the image file name. Model selection – default to GPT-5.4 nano (fastest & cheapest) or switch to GPT-5.4 mini for higher quality; legacy GPT-4o mini and GPT-5 mini/nano remain available. Image size & detail control – choose the resolution and level of visual detail sent. Developer-friendly – filters and actions to customise prompts, models and output, plus optional outgoing webhooks. WordPress Abilities API – registers a generate-alt-text ability (WordPress 6.9+/7.0) so core AI, agents and automation tools can generate alt text. No extra servers – data flows only between your site and OpenAI; nothing is stored off-site. Multilingual output – choose English (UK), English (US) or other popular languages. (English US is the default.) 🧭 Where to find the bulk tool Tools → Bulk Alt Text Update Media → Bulk Alt Text Update (shortcut that redirects to the Tools page) Settings → Alt Text Generator includes a button linking straight to the bulk page 🧠 How it works When an image is uploaded (or manually chosen), the plugin creates a temporary public URL for that image. 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. OpenAI returns a concise description. Alt text is stored in WordPress’ native _wp_attachment_image_alt field. (Optional) The returned title is stored as the attachment post title. Nothing is cached or stored on OpenAI’s side; only the final strings live in your database. Settings overview OpenAI API Key – Required to connect to OpenAI. OpenAI Model – GPT-5.4 nano (default), GPT-5.4 mini, or legacy GPT-4o mini / GPT-5 mini / GPT-5 nano. Image Size to Send – Thumbnail, Medium, Large, or Full. Image Detail Quality – ‘Low’ or ‘High’ (Low uses fewer tokens). Bulk batch size – Number of images per batch (lower values reduce rate-limit risk). Site Context – Optional free-form prompt guidance (brand voice, niche, etc.). Send Image File Name – Include file name in the prompt for extra context. Automatically Generate Title – Add descriptive titles alongside alt text. Use full context for image titles – When enabled, title generation includes site context and file name (uses more tokens). Bulk optimiser delay (seconds) – Pause between batches during bulk runs. OpenAI request timeout (seconds) – Max wait time for OpenAI responses (10–120s) to reduce timeout failures on slower hosts. 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. Webhook URL & signing secret – Optionally POST generated alt text/titles to an external endpoint (with an optional HMAC-SHA256 signature) for automation and logging. Developers The plugin is extensible via standard WordPress hooks, an outgoing webhook, and the WordPress Abilities API. Filters aatg_alt_text_prompt ( $prompt, $post_ID, $context ) – customise the alt-text prompt. aatg_image_title_prompt ( $prompt, $post_ID, $context ) – customise the title prompt. aatg_openai_request_payload ( $payload, $context, $messages ) – customise the full OpenAI request (model, messages, reasoning effort). aatg_generated_alt_text ( $alt_text, $post_ID ) – filter alt text before it is saved. aatg_generated_title ( $title, $post_ID ) – filter the title before it is saved. aatg_is_low_quality_alt ( $is_low, $alt, $post_ID ) – control which existing alt text the bulk tool regenerates. aatg_webhook_payload ( $payload, $post_ID, $result ) – customise the outgoing webhook body. aatg_supported_image_extensions ( $extensions ) – customise which image formats are sent to OpenAI (default: PNG, JPEG, GIF, WebP). Actions aatg_after_alt_text_generated ( $post_ID, $alt_text ) aatg_after_title_generated ( $post_ID, $title ) aatg_after_generation ( $post_ID, $result ) Outgoing webhook Set a Webhook URL under Settings → Integrations & Webhooks to receive a non-blocking JSON POST after each generation. If a signing secret is set, requests include an X-AATG-Signature: sha256=… header (HMAC-SHA256 of the body) so your endpoint can verify authenticity. WordPress Abilities API On WordPress 6.9+ the plugin registers the ability ai-auto-alt-text/generate-alt-text (input: attachment_id) so WordPress core AI, agents, MCP servers and automation tools can generate alt text programmatically. Execute it with wp_get_ability( 'ai-auto-alt-text/generate-alt-text' )->execute( array( 'attachment_id' => 123 ) ). External services This plugin connects to the OpenAI API to generate alt text and (optionally) image titles. Endpoint: https://api.openai.com/v1/chat/completions When called: On image upload (automatic) Via “Generate Alt Text & Title” button in Media Library (manual) Via Tools → Bulk Alt Text Update (bulk) Data sent: image URL, optional file name, optional site context, optional parent post title Terms: https://openai.com/policies/terms-of-use Privacy: https://openai.com/policies/privacy-policy If you configure a Webhook URL, generated alt text/titles (and the image URL) are also sent to that endpoint you control.

AltTextLab – AI Alt Text Generator for WordPress AltTextLab automatically writes accurate, SEO-optimized and accessible alt text for every image in your WordPress media library – the moment you upload, or across your entire existing library in one bulk run. Features Automatic alt text on every upload Every new upload gets alt text generated immediately, no manual trigger needed. Bulk alt text generation with no image limit Process your entire media library – no matter how many images it contains – with fast, reliable bulk processing. Context-aware alt text AltTextLab reads your post title and configured SEO keywords alongside each image, so every description is relevant to the content it appears in. WooCommerce integration AltTextLab reads your product name, brand, color, and material alongside each image to write alt text that serves both screen reader users, search engines, and LLMs. Works with your SEO plugin Integrates natively with Yoast SEO, Rank Math, SEOPress, All in One SEO, The SEO Framework, SmartCrawl, and Squirrly SEO. Focus keyphrases from your SEO plugin are automatically pulled and naturally woven into the generated alt text. Compatible with Gutenberg, Elementor, Divi, Beaver Builder Alt text is written directly to WordPress’s standard media library database – the same field every page builder and theme reads from. There are no sync issues, no custom field mapping. All major image formats supported JPG, PNG, WebP, SVG, and AVIF, including modern formats that other tools often skip. Multi-language support Generate alt text automatically in over 130 languages. WPML Translation Support. Forever free plan available AltTextLab has a permanent free plan that gives you 25 credits per month at no cost. External service for alt text generation This plugin connects to the API provided by AltTextLab.com to create alt text for images using AI. This service is essential for the plugin’s core functionality. What data is sent and when: The plugin may send the following data to AltTextLab when generating alt text: – The image URL or a base64-encoded version of the image – Keywords – The article or product title – Brand and other relevant attributes, depending on plugin settings The plugin may also send a request to fetch the current status of the connected AltTextLab account in order to display account information within the WordPress admin interface. This external service is provided by AltTextLab.com. Terms of Service, Privacy Policy