Automatically Generate Alt‑Text for Images

Automatically Generate Alt‑Text for Images

Ever uploaded a bunch of images to your website and then realized none of them have alt-text? You’re not alone. Writing alt-text for every image is tedious, but skipping it means your site is less accessible and loses valuable SEO points. The good news: you can now automate this with smart, easy-to-use AI tools—even if you aren’t a coder!

Why Automate This

  • Accessibility: Alt-text helps visually impaired users understand content. It’s not just nice—it’s often required by law!
  • SEO: Search engines use alt-text to “see” images and boost your rankings.
  • Time Saver: Let AI suggest or fill in alt-text for you, freeing you up for other work.
  • Consistent Quality: Automation avoids gaps or mismatched descriptions, especially as your site grows.

Step-by-Step Setup

Below are several popular strategies and tools—pick the one that best fits your CMS and workflow. Each one includes an explanation, a workflow description, a JSON payload example, and advice for tweaking it to your needs.

n8n with Google Cloud Vision API

What happens: When you upload a new image to your CMS (like WordPress), n8n watches for the event. It sends the image to Google Cloud Vision, which returns a description suitable for alt-text, and then n8n updates your CMS automatically.

What the setup looks like: Picture a flowchart:
Image Uploaded → n8n → Google Vision → Alt Text Generated → CMS Updated

{
  "image_url": "https://yourcms.com/uploads/blue-shirt.jpg",
  "alt_text": "A folded blue cotton shirt on a wooden table with sunlight."
}

Tips to customize:

  • Ask Google Vision for different languages just by tweaking API parameters.
  • Add conditional steps—e.g., only fill alt-text if missing.
  • Map extra fields like image captions or tags in your flow.

OpenAI Vision WordPress Plugin

What happens: Install the “AI Image Alt Text Generator” WordPress plugin, connect your OpenAI account, and let it work. Every time you upload an image, the plugin analyzes it (using GPT-4o) and writes a human-style alt-text. It even allows bulk-updating existing images, all inside your WordPress media library.

What the setup looks like: You just upload images as usual—behind the scenes:
Image Upload → Plugin Triggered → OpenAI Vision → Alt Text Saved

{
  "image_id": 3152,
  "file_name": "coffee-mug-desk.jpg",
  "alt_text": "White ceramic mug filled with coffee next to a laptop on a tidy workspace."
}

Tips to customize:

  • Control how long or detailed the alt-text is via plugin settings.
  • Set rules to ignore certain image folders or file types.
  • Pick which images get processed in bulk.

n8n-Gemini AI Agent Workflow

What happens: Use n8n with Google Gemini 1.5 Pro (an advanced AI model). This setup can handle images in different formats and even extract text from them. It makes nuanced alt-text, then updates your CMS. It’s great if you want smarter descriptions or need to handle lots of product images.

What the workflow looks like:
Get Image (URL/Binary) → Gemini Analyzes → Generate Alt Text → Push to CMS → Handle Errors

{
  "source": "https://store.com/images/product123.jpg",
  "description": "Red running shoes with white soles on a reflective surface, logo visible."
}

Tips to customize:

  • Set up error alerts via email or Slack if descriptions fail.
  • Resize or compress images during the flow to save bandwidth.
  • Add extra context (like product category) for even richer alt-text.

Automated SEO Audits with n8n

What happens: Every week (or month), n8n scans all your content for images that have no (or bad) alt-text. For each one, it fetches the image, uses AI (Google Vision or OpenAI) to make a description, logs the change in a Google Sheet (for reports or undo), and then updates the CMS. This keeps your site healthy as you add new content.

What the workflow looks like:
Scheduled Trigger → Get All Images → Check Alt-Text → AI Fills In → Log to Sheets → Update Site

{
  "checked_image": "https://blogsite.com/assets/post42-banner.jpg",
  "before": null,
  "after": "Close-up of a handwritten journal next to fresh lavender sprigs."
}

Tips to customize:

  • Set audit frequency to match your publishing schedule.
  • Add Slack or email notifications for audit summaries.
  • Export logs so you can roll back if something goes wrong.

Low-Code Alt-Text Pipelines via Pipedream

What happens: If you already use cloud storage (like Google Drive, Dropbox, or Azure), try linking it to Pipedream, which is a low-code automation tool. Whenever you add new images to a folder, Pipedream runs a function (using Google Cloud Vision or Azure AI) to create alt-text. It then triggers an n8n workflow that puts that text into your CMS fields. Perfect for e-commerce with lots of product photos.

What the workflow looks like:
Cloud Upload → Pipedream Function → AI Alt-Text → n8n Mapping → CMS

{
  "file_location": "dropbox://summer2025/floral-dress-01.jpg",
  "caption": "Colorful floral summer dress on a display mannequin."
}

Tips to customize:

  • Batch process folders overnight for high-volume shops.
  • Map extra fields (price, SKU) while updating product listings.
  • Use conditionals: don’t overwrite alt-text written by a human.

Real Example: Automating Alt-Text in a Small Online Shop

Let’s say you run a boutique T-shirt shop using WordPress. You add dozens of new product images weekly. By connecting WordPress to n8n and the Google Vision API:

  1. Whenever a new T-shirt image is uploaded, n8n grabs the image URL.
  2. It sends the image to Google Vision, which returns “Red T-shirt with a cartoon cat graphic, folded neatly on a white table”.
  3. n8n updates the alt-text in your CMS so visually-impaired shoppers and Google both get the right idea.
  4. A Google Sheet logs every update, so you can check or restore changes if needed.

Tools You’ll Need

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Final Thoughts

Manually writing alt-text for every image is a pain, but bad or missing alt-text means lost sales, frustrated users, or even compliance problems. With these AI-powered, no-code (or low-code) tools, you can automatically keep your images accessible and SEO-friendly—without spending hours at the keyboard. Try one of these methods and see your website become more welcoming to everyone (and maybe rank a little higher, too!).

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