How to Generate OG Images for Blog Posts: Complete Guide

Every time someone shares your blog post on Twitter, LinkedIn, or Slack, the platform scrapes your page for an Open Graph image. If you don't provide one, you get a blank card or an auto-picked thumbnail that makes your content look unfinished. Learning how to generate OG images for blog posts is one of the highest-ROI tasks for any content-driven site — it directly affects click-through rates and how professional your brand appears in feeds.

Why OG Images Matter for Blog Posts

Social platforms use the og:image meta tag to render a preview card alongside your link. A study by Mozilla and numerous growth teams has shown that links with rich preview cards get significantly higher engagement than plain-text links. When your blog post shows up in a crowded feed with a branded, legible image, it earns the click. When it shows up with nothing, it gets scrolled past.

The impact is measurable: posts with custom OG images consistently outperform posts without them in A/B tests of social referral traffic. The image is often the first thing a potential reader sees — before your headline, before your domain name.

OG Image Dimensions and Specifications

Every major platform has slightly different requirements, but one size works well across all of them:

Recommended size: 1200 × 630 pixels
Aspect ratio: 1.91:1
File format: PNG or JPG (PNG for text-heavy images, JPG for photos)
File size: Under 8 MB (keep it under 1 MB for fast scraping)
Safe zone: Keep text and logos within the center 1100 × 570 area, since some platforms crop edges

Facebook, LinkedIn, and Slack all use 1200×630 as their default. Twitter's large card uses a 2:1 ratio (800×400 minimum), but 1200×630 renders acceptably on Twitter too. Design for 1200×630 and you'll be covered everywhere.

How to Generate OG Images for Blog Posts

You have two main approaches: static generation and dynamic generation. Each has tradeoffs.

Static Generation

You create a unique image file for each blog post and reference it in that post's <head>. This is the simplest approach and works fine for sites with a small number of posts.

The workflow:

Design a template in Figma, Canva, or Photoshop.
For each post, duplicate the template and swap in the title, author, and date.
Export as 1200×630 PNG.
Upload and reference in your <meta> tags.

For a faster workflow, use the OG Image Generator to create branded images directly in the browser — pick a template, type your title, and download. No design software required.

Dynamic Generation

For blogs with hundreds of posts or user-generated content, static images don't scale. Dynamic generation creates the image on-demand using a serverless function or edge worker.

A typical setup uses a library like @vercel/og (which renders images using Satori and resvg) or Puppeteer to screenshot an HTML template:

import { ImageResponse } from '@vercel/og';

export async function GET(request) {
  const { searchParams } = new URL(request.url);
  const title = searchParams.get('title');

  return new ImageResponse(
    (
      <div style={{
        display: 'flex', fontSize: 60, width: '100%', height: '100%',
        background: '#0f172a', color: 'white', padding: 80,
      }}>
        {title}
      </div>
    ),
    { width: 1200, height: 630 }
  );
}

This endpoint returns a PNG directly, so your meta tag becomes:

<meta property="og:image" content="https://yoursite.com/api/og?title=Your+Post+Title" />

Dynamic generation means every post gets a custom image automatically — no manual design work per article.

Text Overlay and Branding Best Practices

A good OG image is legible at 400 pixels wide (the size it renders at in most feeds). That constraint drives every design decision:

Use large, bold text. Body text should be at least 40px at 1200×630 resolution. If you can't read it at thumbnail size, it's too small.
Limit text to 5-7 words. Don't paste your full headline. Summarize the core idea.
Add your logo in a consistent corner. This builds brand recognition across every share.
Use high contrast. Dark text on a light background, or vice versa. Avoid gradients behind text.
Keep it simple. One background color, one accent color, one font. Visual noise kills legibility at small sizes.

Common OG Image Mistakes

Using a tiny image. Anything under 600×315 gets ignored or upscaled by some platforms.
Forgetting to set og:image:width and og:image:height. Without these, platforms make an extra request to determine dimensions, slowing down card rendering.
Using a photo with text baked in at low resolution. The text becomes unreadable when scaled down.
Not testing. Always preview your card with the Facebook Sharing Debugger and Twitter's Card Validator before publishing.

Use Cases Beyond Blog Posts

OG images aren't just for articles. Product pages, landing pages, documentation entries, and even individual search results benefit from custom preview images. Any URL that might get shared should have an og:image.

For a deeper dive into the underlying meta tags, check out our free OG image generator guide and our breakdown of OG image best practices to increase click-through rate.

Summary

When you generate OG images for blog posts, you're investing in the first impression every social share makes. Pick the right dimensions (1200×630), keep text large and minimal, brand consistently, and choose between static and dynamic generation based on your content volume. The tools are free and the payoff is immediate — every shared link becomes a small ad for your content.