WordPress has two editors that look almost the same. One changes a page. The other changes every page on your site. Here is how to tell them apart before you find out the hard way.
You are editing a page. You want the heading a bit larger. You click it, you drag the size control, you press Save — and a panel appears saying you are about to save two things, one of which is called Header, and you did not ask to change the header.
That panel is WordPress being careful with you. It is worth understanding why it appeared.
There are two editors
The post editor (Pages ? your page ? Edit, or Posts ? your post) edits one thing. The words on that page. Its blocks, its images, its featured image. Nothing you do in it can affect any other page.
The Site Editor (Appearance ? Editor) edits the site. The header that appears above every page. The footer below it. The layout that every blog post is poured into. The colours and fonts used everywhere.
They share the same block interface — same toolbar, same right-hand sidebar, same drag handles. That is deliberate; you only have to learn one set of controls. It is also exactly why people change the wrong thing.
How to tell, in one second
Look at the address bar.
/wp-admin/post.php?post=1082&action=edit ? post editor. One page.
/wp-admin/site-editor.php ? Site Editor. The whole site.If you would rather not read URLs: the Site Editor opens onto a dark sidebar listing Design, Navigation, Styles, Pages, Modèles et Compositions. The post editor has no such sidebar. It drops you straight into the page.
What lives in which
This is the part worth memorising, because it is the same division every block theme uses.
| You want to change | Editor |
|---|---|
| The words, images and blocks on one page | Post editor |
| A page’s title or featured image | Post editor |
| The logo, the menu, anything in the header | Site Editor |
| The footer | Site Editor |
| What every blog post looks like | Site Editor ? Templates ? Single |
| What the blog listing looks like | Site Editor ? Templates ? Blog Home |
| Colours and fonts across the site | Site Editor ? Styles |
| The 404 page | Site Editor ? Templates ? Page: 404 |
The rule underneath it: a page is content, a template is a shape that content is poured into. Your About page is content. The fact that every page shows a header, then the content, then a footer, is a template.
The vocabulary, briefly
Four words get used interchangeably in tutorials and they are not interchangeable.
- Block — one thing. A paragraph, an image, a button.
- Pattern — a group of blocks arranged into something useful, ready to insert. A pricing table, a hero section. Inserting one gives you a copy; edit it freely, the original is untouched.
- Template — the layout for a kind of page. There is one Single template and it draws all of your posts.
- Template part — a chunk reused across templates. Header and Footer are template parts. Change the Header once and every template that uses it changes.
So when you edit the header, you are editing a template part, and “everywhere” is the entire point of it.
The save panel is your safety net
The Site Editor never saves silently. Press Save and you get Review changes listing everything you are about to alter:
Review changes
? Header Template part
? Styles Custom stylesRead that list. It is the last honest statement of what you actually touched. If it names something you did not intend to change, untick it. If it names three things and you thought you changed one, you have been clicking in the wrong place and it is far cheaper to find out now.
The post editor has no such panel, because it does not need one — it only ever saves that one page.
If you changed the wrong thing
You have not broken anything permanent. Two ways back:
Before you save, the undo arrow works normally, or you can simply leave without saving.
After you save, open Appearance ? Editor ? Templates (or Patterns ? Template Parts), find the item, open the three-dot menu beside it, and choose Réinitialiser. That discards your version and puts the theme’s original back.
?? Reset only appears when there is something to go back to — a version that came with your theme. A template you created yourself has no original, so the menu offers Delete instead. That is not a bug; there is nothing to reset to.
One habit worth forming
Before you change anything global, ask: do I want this on one page, or everywhere?
If the answer is one page, you want the post editor, and you may want a different page template rather than a change to the shared one. If the answer is everywhere, the Site Editor is right and the Review changes panel will confirm it.
Almost every “I edited my site and something weird happened somewhere else” story is that question left unasked.
En bref
- Post editor edits one page. Site Editor edits the site.
- Check the URL, or look for the dark sidebar.
- Header and footer are template parts. Editing them changes every page, by design.
- The Site Editor’s Review changes panel lists exactly what you are saving. Read it.
- Went wrong? Three-dot menu ? Réinitialiser puts the theme’s version back.