Meta Boxes Tab

The Meta boxes tab lists every plugin and theme meta box per post type that uses the block editor, and what each one means for real-time collaboration.

Why this matters#

Classic meta boxes are not synced between editors, so real-time collaboration (planned for a future WordPress release) is turned off on any post that shows one. Knowing which boxes are on which post types tells you which features you would lose and which plugins to ask about.

Reading the tab#

For each post type there is a section headed with its label, its name, and a badge: Ready for collaboration or N meta boxes turn off collaboration. A line underneath says where the data came from: whether the editor was simulated during the scan, whether the simulation failed (and why) so the list comes from real editor visits, and when an administrator last opened that editor.

Column	Contents
Meta box	Title and ID
Added by	The plugin or theme that registered it, with the file and line of the render callback; Unknown when it could not be attributed
Position	normal, side or advanced
Real-time collaboration	One of the verdicts below
Found by	Simulation, Editor visit or Earlier simulation

Core WordPress meta boxes are not listed; a line at the bottom of each section says how many there were.

Collaboration verdicts#

Verdict	Meaning
Turns off collaboration	A classic meta box without any compatibility flag. Collaboration will be disabled on posts that show it.
Incompatible with the block editor	Registered with __block_editor_compatible_meta_box => false; the block editor shows a notice instead of the fields.
Declares collaboration support	Registered with __rtc_compatible_meta_box => true. Treated as safe.
Classic editor only (hidden)	Registered with __back_compat_meta_box => true; not shown in the block editor at all, so it cannot block anything.