Live Preview Button missing for block themes

[ninomiho]

This is a follow-up to #54578.

In #54578, the Live Preview button was removed from a couple of places for block themes since the site editor preview was not working when previewing from classic themes. It was decided to remove the Live Preview button from block themes until it was implemented in Gutenberg (​https://github.com/WordPress/gutenberg/issues/37201) to enable the site editor for non-active block themes. That feature has been implemented, and now Live Preview works for block themes. We should show the Live Preview button for block themes again.

Steps:

1. Install a block theme like TwentyTwentyFive
2. Go to Appearance -> Themes
3. Click on the TwentyTwentyFive theme
4. There is only the Active button instead of having Live Preview and Active

1. Upload a block theme like TwentyTwentyFive
2. After the theme is uploaded, there is no Live Preview button

[matt]

Would love to see this fixed.

What this changes

• Shows “Live Preview” for inactive block themes on Themes and Add Themes screens.

How to test
1) Install Twenty Twenty-Five, keep it inactive → Appearance → Themes → Details → “Live Preview” is present.
2) Click it → Site Editor opens with ?wp_theme_preview=<stylesheet>.
3) Upload a block theme zip → success card shows “Live Preview” and behaves as above.
4) Classic themes still preview via the Customizer.

Trac ticket: https://core.trac.wordpress.org/ticket/64159

[ninomiho]

PR opened: ​https://github.com/WordPress/wordpress-develop/pull/10469

Restores the Live Preview button for non-active block themes (as per the ticket).

Testing instructions:

1) Install Twenty Twenty-Five, keep it inactive → Appearance → Themes → Details → “Live Preview” is present.
2) Click it → Site Editor opens with ?wp_theme_preview=<stylesheet>.
3) Upload a block theme zip → success card shows “Live Preview” and behaves as above.
4) Classic themes still preview via the Customizer.

[praful2111]

Test Report

Description

The issue is fixed with the PR mentioned below.

PR tested: ​https://github.com/WordPress/wordpress-develop/pull/10469

Environment

• WordPress: 6.9-beta3-20251105.102621
• PHP: 7.4.31-dev
• Server: PHP.wasm
• Database: WP_SQLite_Driver (Server: 8.0.38 / Client: 3.40.1)
• Browser: Chrome 141.0.0.0
• OS: Linux
• Theme: Twenty Eleven 4.9
• MU Plugins: None activated
• Plugins:
  • Test Reports 1.2.0

Actual Results

1. ✅ Issue resolved with a PR.

[dhruval04]

Test Report

Description

The issue is fixed

PR tested: ​https://github.com/WordPress/wordpress-develop/pull/10469

Environment

• WordPress: 6.9-beta3-20251105.102621
• PHP: 8.4
• Server: PHP.wasm
• Database: WP_SQLite_Driver (Server: 8.0.38 / Client: 3.40.1)
• Browser: Chrome 131.0.6778.108
• OS: Linux
• Theme: Twenty Twenty-Three
• MU Plugins: None activated
• Plugins:
  • Test Reports 1.2.0

Actual Results

✅ Issue resolved with a PR.

[mlaetitia1986]

Side by side - before & after

[mlaetitia1986]

Just adding some screenshots of the feature test.

Steps:

1. Head to WP Admin -> Appearance -> Themes -> Add theme
2. Choose a Block theme , install it but do not activate it
3. Open Appearance -> Themes -> newly installed theme -> Details & preview

Before the fix, Live Preview button wasn't visible and it is after the fix.

(note: tested in playground).

Before & after:

[westonruter]

In 61195:

Themes: Restore 'Live Preview' button for block themes.

Note that the return query parameter is not yet functional in the Site Editor. See ​Gutenberg#47934.

Follow-up to [52341], [52346], [52353], [52802].

Props ninomiho, mcsf, dhruval04, praful2111, mlaetitia1986.
See #54578.
Fixes #64159.

Thanks @westonruter!

[mcsf]

That was fast — thank you, @westonruter and @ellatrix!

[ninomiho]

Thank you everyone!