The iframed post editor becomes unconditional in WordPress 7.1. In 7.0 a single legacy block in your test post switched the iframe off, which means many blocks were never actually tested in it.
The Custom HTML block can now interleave static markup with real, editable inner blocks that are locked in place. The markup pattern, the innerContent variation field, a legacy conversion walkthrough, and where this beats a pattern or a custom block.
The WordPress Icons API in 7.1 turns the built-in icon set into a public registry. The registration functions, wp_get_icon(), REST routes, what the SVG sanitizer strips, and a five-stage migration plan.
WordPress 7.1 was going to move the block editor to React 19. It is not. Core enabled it in Gutenberg, hit interop problems with plugins and reverted, so 7.1 ships on React 18.3. What happened, what it means if you already migrated, and the change that is now the real compatibility risk.
Gutenberg 23.5 replaces the desktop, tablet and mobile toggle with a freely resizable preview, and useResizeCanvas is deprecated and non-operational. What to migrate to, plus the layout changes shipping alongside.
All 330 icons in @wordpress/icons v15 declare fill=currentColor, so tinting with the CSS fill property stops working the way you expect. What breaks, how to find it, and what the new Icons API is building toward.
The __next40pxDefaultSize prop is now a no-op across roughly twenty components in @wordpress/components, and 40 pixel controls are permanent in WordPress 7.1. How to find every call site, fix the layouts that assumed the old size, and test before 19 August.
WordPress 7.1 was going to move the block editor from React 18 to React 19. It does not: core hit interop problems and reverted, so 7.1 ships on React 18.3. The migration is deferred, not cancelled, and the work to prepare your blocks is unchanged.
Master WordPress Full Site Editing with this complete guide to theme.json, block templates, Global Styles, and migrating from classic themes. Learn FSE development for 2026 with practical code examples.
WordPress weekly roundup April 24 to May 1, 2025: WordPress 6.8.1 released, GDPR compliance updates, WordCamp announcements, and plugin news from the week.