You went to change the phone number in your header. You opened Appearance, expecting the Customizer you used last year, and instead you’re staring at a menu with Templates, Patterns, and Styles. Or the opposite: you expected the Site Editor and there’s no Editor link anywhere.
Nothing is broken. You’re just looking at a different kind of theme than you assumed. This matters because the header lives in a completely different place depending on which one you have, and clicking around hoping to find it is how people end up editing a template that applies to every page on the site.
Here’s how to tell which one you have, and what it means for your header.
The one-link test
Go to your WordPress dashboard and look at the Appearance menu in the left sidebar.
If you see Appearance > Editor, you have a block theme and the Site Editor is active. That’s the whole test. WordPress documentation is direct about it: “Once you install and activate a Block theme on your site, go to Appearance > Editor to open the Site Editor.”
If you see Appearance > Customize instead, you have a classic theme. The Site Editor is not available to you, and it isn’t a setting you can switch on. The same documentation states plainly that “The Site Editor is only available when you install and activate a Block theme on your site.”
Some sites show both links. That usually means a plugin is forcing the Customizer to stay visible, or you’re on a hybrid theme — a classic theme that has adopted some block features. The developer handbook describes hybrids as “merely classic themes that have adopted some modern block-related features,” and notes the term isn’t an official theme type. For your purposes, treat it as classic: the header is probably still in the Customizer or theme options, not the Site Editor.
Why the distinction exists at all
Block themes arrived in WordPress 5.9 as “a new type of theme built with and for blocks,” according to the block themes documentation. In a block theme, the header, footer, navigation, and page layouts are all built from blocks — the same blocks you already use when writing a post.
Classic themes predate that. They’re built from PHP template files and a functions.php file, and they expose their settings through the Customizer, a dedicated Menus screen, and widget areas. The documentation is blunt about the split: “Classic themes do not work with the Site Editor.”
So this isn’t a preference or a version issue. It’s two different editing systems, and your theme determines which one you get.
What this changes about editing your header
If you have a block theme
Your header is a template part. WordPress defines a template part as “a block for managing the repeating global areas of the site such as a Header, Footer, Sidebar, etc.”
To reach it: Appearance > Editor, then click Patterns in the left navigation, then Template Parts, then Header. Click the pencil icon to edit. You’ll see the header as a stack of blocks — a Site Title block, a Navigation block, a logo, whatever your theme includes. Click the block you want to change and edit it the way you’d edit a paragraph.
Before you save, read this part carefully. When you save changes to a header template part, WordPress will show you a list of everything you’ve changed — synced patterns, navigation menus, templates, template parts — and let you choose what to save. The documentation warns that “some changes (like changes to the Header and Footer templates) will apply to all pages of your site that use those templates, and not just the page you were working on.”
That’s not a bug. That’s the point of a header. But it’s worth knowing before you click Save, because there’s no per-page undo button waiting for you.
If you only want to change the site title, tagline, logo, or icon, you may not need the header template at all. The Site Editor has an Identity section for exactly those four things at the site level. Try that first — it’s the smaller, safer edit.
If you have a classic theme
Your header is not a block. It’s rendered by a PHP file, and what you can change about it depends entirely on what the theme author exposed.
Start with Appearance > Customize. Look for a Header, Site Identity, or Theme Options panel. Many classic themes let you swap a logo, edit the site title and tagline, and sometimes change header layout or colors from there. That’s the intended path, and it’s safe.
If the thing you want to change isn’t in the Customizer, check whether your theme has its own settings page — often under Appearance or as a top-level menu item. Theme authors put header controls in different places, and there’s no universal rule.
What you should not do is open Appearance > Theme File Editor and start editing header.php. The documentation for that screen is unusually direct: “Be very careful editing PHP files of your current theme. The editor does not make backup copies. If you introduce an error that crashes your site, you cannot use the editor to fix the problem.” It also notes that theme updates will erase anything you change there.
If the header change you want genuinely isn’t available in the Customizer or theme options, that’s a signal to either accept the current header or look at a different theme — not to start editing PHP from wp-admin.
“But I was told my theme was a block theme”
This happens. A few common reasons:
You’re looking at the wrong site. If you manage more than one WordPress install, it’s easy to be logged into the one with the classic theme. Check the site name in the top-left of the admin bar.
The theme is a hybrid. It may use block template parts for some things while still being a classic theme overall. The Appearance menu will tell you — if Customize is there and Editor isn’t, you’re on the classic side of the line.
You’re on a child theme of a block theme. Usually this still shows Appearance > Editor. If it doesn’t, the child theme may not have declared block theme support properly.
You read about block themes and assumed yours qualified. Block themes were introduced in 5.9, but that doesn’t mean every theme released since then is one. Plenty of actively maintained themes are still classic, and that’s a legitimate choice by their authors.
To check what you actually have: go to Appearance > Themes. Your active theme is shown there. If you want to browse block themes specifically, the Add New screen has a Block Themes filter in the toolbar that shows only themes with full site editing support.
If you switch themes to get the Site Editor
You can. It’s a normal thing to do. But do it with your eyes open.
Switching from a classic theme to a block theme will change how your site looks, because the new theme brings its own templates and styles. Your content — posts, pages, media — stays. Your menus may need to be reassigned. Any header settings you had in the old theme’s Customizer don’t carry over, because they belonged to that theme.
Before switching, note two things: what your current header contains (logo, menu, phone number, anything custom), and whether your site has any theme-specific functionality you rely on. The developer handbook makes the general point that themes control presentation while plugins control behavior, and that critical functionality should live in a plugin so it survives a theme change. If something important about your site is baked into the theme, switching will take it with it.
If you’re not sure, the block themes documentation suggests setting up a test site first to try a block theme before committing. That’s good advice if you have the option. If you don’t, at minimum take a backup through your host’s control panel before you switch.
What looks alarming but isn’t
If you edit a header template part and something goes sideways, you may see a maintenance screen, a white page, or an email about a critical error. This looks worse than it is, and the order of operations matters more than speed.
First: don’t keep clicking. Second: if you can still reach wp-admin, go to Appearance > Themes and activate a different theme. WordPress will fall back to it and your site will come back. Third: if you can’t reach wp-admin, your host’s control panel usually has a way to rename or deactivate a theme folder — that forces WordPress to use a default theme and gets you back in.
In a block theme, most header mistakes are recoverable without any of that. The Site Editor keeps style revisions, and you can reset a template to its default state from the Templates list using the three-dot menu. The documentation notes that resetting “will reset the template to the default state and you will lose the changes you made to that template” — so it’s a real reset, not an undo. But it’s a clean way back to a working header.
None of this is a reason to avoid editing your header. It’s a reason to know which system you’re in before you start, so you’re making the edit in the right place the first time.
Questions that come up
Can I get the Site Editor on a classic theme?
No. The Site Editor requires a block theme. There’s no plugin or setting that adds it to a classic theme. You’d need to switch themes.
My Appearance menu has Customize but no Editor. Is something wrong?
No. That’s what a classic theme looks like. Your header edits happen in the Customizer or your theme’s own options page.
I edited my header and it changed on every page. Can I undo just one page?
Not really, because the header is shared by design. In a block theme, you can reset the header template part to its default, or edit it again to correct the change. There’s no per-page version of a header.
Where did the Menus screen go?
Block themes use a Navigation block instead of the classic Menus screen. You’ll find it under Appearance > Editor > Navigation, or inside the header template part itself.
Is it safe to click around in the Site Editor to see what’s there?
Looking is safe. Nothing saves until you click Save, and WordPress will prompt you before leaving with unsaved changes. The risk is in the saving, not the browsing — so explore freely, and read the save dialog carefully when you’re ready to commit.
Sources
- WordPress Documentation, Site Editor — access requirements, template parts, save behavior, style revisions, reset options.
- WordPress Documentation, Block themes — introduction in 5.9, differences from classic themes, Customizer availability, how to find block themes.
- WordPress Developer Handbook, What Is a Theme? — block, classic, and hybrid theme types; themes vs. plugins.
- WordPress Documentation, Appearance Theme File Editor Screen — warnings about editing PHP files and theme update behavior.
- WordPress Documentation, Template Editor — template editing via the Site Editor, resetting customizations.