Tor N. Johnson

This plugin enables themes to specify a different single.php template based on post category. As posts can have multiple categories assigned, it uses the following to select which possible custom template to use:
1) Categories directly assigned 
 — Check for extant single-CATEGORYID.php files and prioritize based on category order 
2) Parents of categories 
 — Parents are checked based on category order of the directly assigned categories.
Note, the above assumes that there’s a category order plugin installed. If the categories are NOT in a specific order AND there are multiple categories assigned per post then the template selection will be left up to the server. Naturally, if there is only category assigned per post (or only one possible template per post), then there will be no issue.
<h3>Requirements</h3>

Custom-Single

Enables themes to support custom single.php templates per category in the form single-CATEGORYID.php.

vegacorp

Jose Vega

Green Jay Media

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Easily convert posts into landing pages
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Hide headers on single posts pages
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Remove the logo, menu, and the entire page header when viewing posts
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No code required. You just enable the option when creating posts and done. 
It works with all WordPress themes.
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</ul>
<iframe loading="lazy" class="youtube-player" width="750" height="422" src="https://www.youtube.com/embed/spyrpgd-oyA?version=3&rel=1&showsearch=0&showinfo=1&iv_load_policy=1&fs=1&hl=en-US&autohide=2&wmode=transparent" allowfullscreen="true" style="border:0;" sandbox="allow-scripts allow-same-origin allow-popups allow-presentation allow-popups-to-escape-sandbox"></iframe>
<h3>How it works</h3>
Using a creative way we’re able to find the header on posts and hide it.
It works with all WordPress themes.
It’s great for creating landing pages out of your WordPress posts.
<h3>Go Premium</h3>
The free version lets you hide headers on single posts only.
<a href="https://wppagetemplates.com/try-hide-headers-wporg" rel="nofollow ugc">Try Pro Plugin for Free for 7 Days</a>
The premium version lets you hide headers and sidebars on ALL POST TYPES.
<ul>
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Hide headers on pages / Convert pages into landing pages
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Hide headers on product pages / Convert products into landing pages
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Hide headers on the WooCommerce cart page and increase conversions
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Hide headers on the WooCommerce checkout page and increase sales
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Hide headers on event pages / Convert events into landing pages
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Hide headers on any post type / Convert any post type into landing pages
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Hide sidebars on pages / Make any page full width
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Hide sidebars on event pages / Make events full width
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Hide footer on posts, pages, products, events
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Make the WooCommerce cart page full width
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Make the WooCommerce checkout page full width
</li>
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And more.
</li>
</ul>
<a href="https://wppagetemplates.com/try-hide-headers-wporg" rel="nofollow ugc">Try Pro Plugin for Free for 7 Days</a>
<iframe loading="lazy" class="youtube-player" width="750" height="422" src="https://www.youtube.com/embed/c2KBLNvQWzA?version=3&rel=1&showsearch=0&showinfo=1&iv_load_policy=1&fs=1&hl=en-US&autohide=2&wmode=transparent" allowfullscreen="true" style="border:0;" sandbox="allow-scripts allow-same-origin allow-popups allow-presentation allow-popups-to-escape-sandbox"></iframe>

Custom-Single vs Hide Header on Posts for Landing Pages