Pixel-accurate SERP truncation and OG image validation without a browser?

Problem

I'm building a CMS publishing pipeline where I need to validate SEO metadata before content goes live. I need to:

Detect if a SERP title will be truncated in Google search results

Validate Open Graph image dimensions before publishing

Validate Twitter/X Card images per card type (summary vs summary_large_image)

What I'm doing now

// ❌ Inaccurate — character count ≠ pixel width if (title.length > 60) { console.warn('Title might be too long'); } // ❌ Incomplete OG validation if (width < 1200 || height < 630) { console.warn('OG image too small'); }

Why this fails

Google truncates SERP titles based on pixel width (~580px), not character count. Wide characters like W or M get cut much earlier than narrow ones like i or l.

OG image validation rules differ between platforms — Facebook, LinkedIn, and Twitter/X each have different minimum dimension requirements.

summary and summary_large_image Twitter Card types have different image size requirements that I'm not handling.

I need this to run in Node.js / CI — no headless browser, no canvas, no DOM.

What I want

// Pixel-accurate title truncation const serp = generateSerpPreview({ title: 'Buy Premium Running Shoes Online — Free Worldwide Shipping Today', description: 'Shop the best running shoes with free shipping.', url: 'https://example.com/shoes', }); // serp.titleTruncated → true // serp.displayUrl → 'example.com › shoes' // OG image validation const og = generateOgPreview({ title: 'Running Shoes', description: 'Best running shoes online.', url: 'https://example.com/shoes', image: { url: 'https://example.com/og.jpg', width: 800, height: 400 }, });