Every WordPress site eventually hits the same wall: the content calendar is full, but the featured images are stock photos everyone has seen a hundred times, or a plain coloured block with the post title on it. Custom illustration is expensive, and a designer cannot turn around twenty blog headers a week for a small client budget.
AI image models have become a realistic way to fill that gap, as long as you treat the output like any other image asset and run it through a proper WordPress workflow. Below is a process that works well for client sites, built around Google’s Nano Banana 2 and the standard tools already in a WordPress stack.
Why text rendering changes the equation for blogs
Featured images on blogs, newsletters and social cards often need words: a short headline, a category label, a number for a listicle. Older image generators produced warped, misspelled lettering, which forced a second pass in a design tool for every image.
The Nano Banana family of Gemini image models prints text placed in double quotes letter for letter. That means a header like a “WORDPRESS SECURITY CHECKLIST” title card or a “STEP 3” label can come straight out of the generator. You should still proofread every image, but the error rate is low enough to fit into a weekly publishing routine.
Step 1: Decide sizes before you prompt
The biggest time sink is generating an image in the wrong shape and cropping it to death. Check what your theme actually needs first:
- Featured image and blog header: most themes use a wide crop, so 16:9 or 3:2 works well.
- Full-width hero sections: 21:9 gives a cinematic banner that suits block themes and page builders.
- Social share (Open Graph) image: generate at 16:9 and crop a little for the common 1200 by 630 card.
- Pinterest or Stories promotion: 2:3 or 9:16.
Nano Banana 2 supports ten aspect ratios from 1:1 to 21:9, so there is almost always a native match for your theme’s layout.
Step 2: Write a prompt template for the site
Consistency matters more than any individual image. A blog where every header shares the same style looks designed. One where each image is a different aesthetic looks generated. Build one template per site and only swap the subject and the quoted text:
Flat editorial illustration in a limited palette of navy, coral and cream, subtle paper grain, generous empty space on the left third for layout. Subject: a laptop on a desk with a padlock icon floating above the screen. Title text in bold geometric sans serif reading “HARDEN YOUR LOGIN PAGE”, placed top left. Crisp legible lettering, no other text.
“No other text” stops the model adding stray words. Leaving empty space on one side gives your theme room to overlay a title or category badge if it does that by default.
For brand consistency, the model accepts up to 14 reference images. Uploading a logo, a palette swatch and two previous headers keeps new images in the same family.
Step 3: Generate cheap, render once
I generate headers with Nano Banana 2 on PixelDojo, where it costs 2.25 credits per image at 1K, 3 at 2K and 4.5 at 4K, and a run can return up to four images at once to compare layouts. The lighter Nano Banana 2 Lite is 2 credits at 1K and is fine for quick drafts.
For web use, you rarely need 4K. A 2K render is plenty for a 1200 to 1600 pixel wide featured image and keeps downloads manageable. Save 4K for hero banners on large screens or for images that will also be used in print.
Step 4: Optimise before uploading to WordPress
This is where most AI-assisted blogs lose their performance gains. Large PNG files straight from a generator will hurt Largest Contentful Paint, especially when the featured image is the LCP element at the top of every post.
- Resize to the largest size your theme displays. WordPress creates smaller intermediate sizes and srcset entries automatically, but it cannot fix an oversized original.
- Convert to WebP or AVIF. Recent WordPress versions handle both formats natively, and most optimisation plugins can convert on upload.
- Compress with your usual plugin or a command line tool. Illustrations with flat colour compress very well.
- Rename the file to something descriptive, like harden-wordpress-login-page.webp, instead of a generator’s random string.
Step 5: Handle SEO and accessibility properly
An AI image is still an image to Google and to screen readers, so the usual rules apply.
- Alt text: describe what the image shows and repeat any text inside it. If the header says “HARDEN YOUR LOGIN PAGE”, screen reader users need those words too.
- Do not stuff keywords into alt text or file names. Describe, do not pitch.
- Set the featured image explicitly so your SEO plugin uses it for Open Graph and schema output.
- Disclose where it matters. If an image shows realistic people or real places, consider a short caption noting it was generated.
- Keep an archive. Store the prompt with each image, in a custom field or a simple spreadsheet, so you can regenerate in the same style when you refresh old posts.
Treated this way, generated images become one more part of a disciplined WordPress content process rather than a shortcut. The prompt template keeps the brand consistent, the optimisation step protects Core Web Vitals, and the alt text keeps the site accessible. The result is a blog that looks designed, loads fast and stays easy to maintain as the post count grows.