Rendering a WordPress Post as a Downloadable PDF

A recipe site, a documentation page, a long-form guide, readers keep asking for a “Download as PDF” button so they can read it offline or print it without the theme’s header, sidebar, and comment thread fighting for space on the same page. WordPress already renders a post as HTML on every request, turning that same content into a PDF instead of a webpage is a different rendering target, and it’s one core has no opinion on.

Why this needs a package

WordPress has no PDF renderer. The the_content filter gives you a post’s fully rendered HTML, blocks resolved, shortcodes expanded, embeds processed, but turning HTML into a PDF byte stream is a separate problem. dompdf (dompdf/dompdf) does exactly that: feed it HTML and CSS, it lays the page out and returns PDF bytes, no separate drawing API to learn on top of it. That matters here specifically: a post’s content is already HTML the moment the_content runs it, not a document that has to be built field by field the way a library like TCPDF expects.

The route

<?php

declare(strict_types=1);

use Dompdf\Dompdf;

class PostPdf
{
    public function get(WP_REST_Request $request): void
    {
        $postId = (int) $request->get_param('post_id');
        $post   = get_post($postId);

        if ($post === null || $post->post_status !== 'publish') {
            wp_die(esc_html('No published post with that id.'), '', ['response' => 404]);
        }

        $dompdf = new Dompdf();
        $dompdf->loadHtml($this->postHtml($post));
        $dompdf->setPaper('A4');
        $dompdf->render();

        header('Content-Type: application/pdf');
        header('Content-Disposition: inline; filename="' . sanitize_title($post->post_title) . '.pdf"');
        header('Cache-Control: public, max-age=3600');
        echo $dompdf->output();
        exit;
    }

    private function postHtml(WP_Post $post): string
    {
        $title = esc_html($post->post_title);

        // Already-safe rendered HTML from WordPress's own content pipeline, not raw
        // post_content (unrendered block markup for a block-based post) and not run through
        // esc_html() here, that would mangle every tag instead of escaping untrusted text.
        $content = apply_filters('the_content', $post->post_content);

        return <<<HTML
            <html>
                <body style="font-family: sans-serif;">
                    <h1>{$title}</h1>
                    {$content}
                </body>
            </html>
            HTML;
    }

    public function permission(): bool
    {
        return true;
    }
}

composer require dompdf/dompdf
lps composer push

the_content is a filter, not a method on $post, calling it directly (rather than the global the_content() template tag, which echoes and depends on the loop being set up) is what makes this work outside a normal template context. Running it here means shortcodes, embeds, and any other plugin hooked into content rendering all still apply, the PDF shows the same content a visitor would actually see, not a raw, half-rendered block editor string.

Now call it

curl https://your-site.com/wp-json/loopress-api/v1/post-pdf/482 \
  -o my-post.pdf

That writes an actual my-post.pdf to disk, -o instead of letting curl dump raw PDF bytes to the terminal. A browser hitting the same URL directly opens it inline instead, Content-Disposition: inline is what the route sends.

Permission

A published post is exactly as public as the post itself already is through the theme, so this route stays open. The post_status !== 'publish' check does double duty, it’s the not-found guard, and it’s what keeps a draft or a private post from being exportable through this route just because someone guesses its ID.

If dompdf isn’t installed

Without dompdf/dompdf installed, Dompdf is an undefined class, an ordinary PHP error scoped to this request. Loopress only catches and logs a corrupted or missing vendor/autoload.php itself, not a single package missing from an otherwise intact one, install it through Composer dependency management before pushing this route.

What this opens up

The same shape covers any post type with a “download” or “print” need, documentation pages, recipe posts, long-form guides, a portfolio piece. It’s also a narrow file, one lookup, one HTML template, one render call, that’s a reasonable one to have an AI coding assistant draft, the choice of what to include in the printed layout, a featured image, an author byline, category tags, being exactly the kind of decision worth making deliberately rather than trusting a first pass on.

Custom API Routes and Composer dependency management ship with Loopress Full, a free WordPress plugin and CLI for managing custom code and dependencies as version-controlled files instead of pasting into wp-admin.

Getting Started walks through connecting it to your site in under a minute. Writing Route Files covers the complete file reference.