What's New in WordPress 7.1 "Mary Lou"

WordPress 7.1 “Mary Lou” includes many technical improvements alongside its user-facing features. This article covers the technical specifications and new capabilities for developers, theme authors, and site builders.

Enhanced Responsive Controls

Theme.json Breakpoints

Block themes can now define custom mobile and tablet breakpoints directly in theme.json. This overrides the default WordPress breakpoints for responsive styles and block visibility, giving theme authors precise control over how layouts adapt.

{
  "settings": {
    "breakpoints": {
      "mobile": "480px",
      "tablet": "768px"
    }
  }
}

Responsive Styling in Global Styles

Developers can now style blocks at different screen sizes directly from Global Styles or individual block settings. This works without custom CSS and can be previewed at various viewport sizes in real time.

New Block APIs

SVG Icon API (Now Public)

The SVG Icon API is now a public API. Developers can register custom icon collections and use them throughout the editor:

wp_register_icon_collection() – Register a new icon collection
wp_register_icon() – Register individual icons within a collection
wp_get_icon() – Retrieve registered icons

This allows plugin and theme developers to extend WordPress’s built-in icon library with their own collections.

Pseudo-State Styling

Theme authors can now style Button blocks for different states directly through theme.json.

{
  "styles": {
    "blocks": {
      "core/button": {
        "pseudoStates": {
          "hover": { "color": { "background": "#0073aa" } },
          "focus": { "color": { "background": "#005a87" } },
          "active": { "color": { "background": "#004466" } }
        }
      }
    }
  }
}

These styles can be applied to individual buttons or globally to all buttons.

Abilities API

Building on the infrastructure from WordPress 6.9, the Abilities API now includes:

Filterable execution lifecycle – More control over how abilities run
Custom validation – Define validation rules for ability inputs
Shared discovery – Find and use abilities across the system

This makes it easier to build integrations and automation on top of WordPress, including AI-powered tools.

New Design System

WordPress 7.1 introduces a new Design System for theming admin interfaces:

Semantic Design Tokens

Color tokens for consistent theming
Roundness controls for UI elements
Cursor style customization

ThemeProvider React Component

Developers can use the ThemeProvider component to bring consistent styling to custom admin interfaces while maintaining the WordPress look and feel.

Browser-Based Image Processing

WebAssembly Implementation

Image compression, resizing, and thumbnail generation now run in the browser using a WebAssembly build of libvips. This has several benefits:

Reduced server load – Processing happens client-side
No PHP memory limits – Large files won’t hit memory limits
No upload timeouts – Processing doesn’t block server resources
Smaller files – More efficient compression

Opt-In GIF-to-Video Conversion

GIFs can be converted to video format, typically producing much smaller files while preserving animation quality.

Upload Improvements

Progress indicators for upload status
Automatic retries for failed uploads
More reliable handling of connection drops

New Media Formats

WordPress 7.1 natively supports:

AVIF – Modern, efficient image format
HEIC – Apple’s high-efficiency image format
HDR gain maps – High dynamic range image support

These formats are already used by modern cameras and phones, so they work out of the box.

Editor Architecture Changes

Fully Iframed Post Editor

The post editor is now fully iframed for all themes, matching the Site Editor. This change:

Prevents admin styles from interfering with content
Makes responsive layouts more predictable
Ensures consistent editing experience across themes

The editing canvas runs separately from the WordPress admin interface, so viewport-relative units and media queries target the editing canvas directly.

Accessibility Improvements

New Tooltip Functions

wp_get_tooltip() – Accessible tooltip implementation
wp_get_toggletip() – Toggleable tooltip alternative

These functions bring accessible tooltips to more admin areas, including:

Post meta boxes
Login screen
Various admin interfaces

Improved Screen Reader Support

Clearer labeling throughout admin
More predictable navigation in post list tables
Accessibility enhancements for new Tab and Playlist blocks

Media Library Updates

Infinite Scrolling

The Media Library now uses infinite scrolling by default. Users can opt to return to traditional pagination through a per-user setting.

Speculative Loading

Defaults for speculative loading can now be configured through:

Environment variables
WordPress constants

This gives hosts and site owners control over how WordPress prefetches pages without requiring a plugin.

DataViews and DataForm

New filters are available for configuring the DataViews and DataForm screens that power:

Pages
Templates
Template Parts
Patterns

These provide more flexibility for theme and plugin developers to customize admin interfaces.

WordPress 7.1 “Mary Lou” Released on 19 August 2026

Summary

WordPress 7.1 “Mary Lou” introduces significant technical improvements across:

Responsive styling capabilities
Developer APIs and extensibility
Media handling and performance
Accessibility standards
Admin interface customization

These changes make WordPress more powerful and flexible for developers while creating a better experience for all users.

What’s New in WordPress 7.1 “Mary Lou”