A custom WordPress theme from an agency in 2026 costs $5-20K and takes 4-8 weeks. AI theme generators produce a comparable result in 5-15 minutes for $19/month. The catch: you still need taste and a clear brief. Here is what actually works.
Block themes vs classic themes — which to pick
Block themes (FSE — Full Site Editing) are the WordPress future. Everything editable in the Site Editor. theme.json drives the design system. Newer, more flexible, harder to build by hand. Shaker generates block themes by default.
Classic themes are PHP templates: header.php, footer.php, single.php. Older but battle-tested. Still required for some hosting setups and many WooCommerce extensions.
Rule of thumb: new site = block theme. Existing site with classic theme dependencies = stay classic and have Shaker generate a classic theme.
What the AI actually generates
For block themes: style.css, theme.json (color palette, typography, spacing scale), templates/*.html (front, archive, single, search, 404), parts/*.html (header, footer, sidebar), and functions.php with enqueues + theme support.
For classic themes: full PHP template hierarchy + functions.php + custom post types if asked + WooCommerce template overrides.
For WooCommerce: shop page, single product, cart, checkout, my-account, all themed to match your brand.
Step 1 — Brief
Pick "WordPress Theme" or "WooCommerce Theme" template. Prompt: "A WordPress block theme for a vegan bakery in Portland. Earthy palette: terracotta, cream, sage. Serif headlines, sans body. Front page with hero, featured products, about, testimonials. Block theme (FSE)."
Specifics matter: name your colours, name your fonts (or describe the vibe), list the pages you want.
Step 2 — Generate
Multi-agent pipeline kicks in: Architect plans the templates, Designer picks the palette and typography, Engineer writes the code. 5-15 minutes depending on theme complexity.
You get a downloadable .zip of the theme plus a live preview URL on a Shaker-managed WordPress instance.
Step 3 — Install on your WordPress
WP Admin → Appearance → Themes → Add New → Upload. Pick the .zip. Activate. Done.
For WooCommerce themes: install WooCommerce first if you have not. Then upload + activate the theme. Product page templates auto-apply.
Step 4 — Iterate
Use the WordPress Site Editor to tweak block themes visually. Or open the generated PHP/CSS and edit by hand — it is real code, not obfuscated.
Need a redesign? Regenerate with an updated brief. Each generation produces a fresh theme; pick the best, iterate.
When AI themes fall short
Very complex animation-heavy designs — AI is fine but a designer will polish faster.
Heavily custom WooCommerce flows (B2B, complex variations) — generated themes are a strong base, but a dev will need to extend.
Pixel-perfect brand-book replication — bring the brand book; the AI will get 80% of the way, you finish the polish.
Try it
See https://shakerapp.ai/templates/wp-classic-theme and https://shakerapp.ai/templates/wp-fse-theme. Free tier covers a sample generation.