When someone shares your link, the preview card does the selling. A blank or stretched image makes a good article look careless, while a clean card with a clear title earns the click. The catch is that every platform wants the same thing: a 1200x630 image referenced from a couple of meta tags.
The Open Graph image generator builds that card and exports it at the exact size, in your browser.
TL;DR: Write a title and subtitle, pick a theme, export a 1200x630 PNG, and point your og:image and twitter:image tags at it.
Get the size right
The standard is 1200x630 pixels. Smaller images get upscaled and look soft; the wrong ratio gets cropped and cuts off your text. Designing at the target size from the start avoids both. This tool exports at 1200x630 so you don’t have to think about it.
Write for a glance
A preview card is read in passing, so the words have to land fast. Keep the title to one strong line, use the subtitle for a short supporting sentence, and put your site or handle where it’s visible but quiet. Pick a layout (left-aligned reads like an article, centered reads like a quote) and an accent color that matches your brand. Drop in a logo if you have one.
Wire up the meta tags
Once you’ve exported the PNG, upload it somewhere public and reference it in the page’s <head>:
<meta property="og:title" content="Your title" />
<meta property="og:description" content="A short supporting line." />
<meta property="og:image" content="https://yoursite.com/og/post.png" />
<meta name="twitter:card" content="summary_large_image" />
<meta name="twitter:image" content="https://yoursite.com/og/post.png" />The image URL has to be publicly reachable. A link behind a login or a localhost address won’t render for the scraper.
When the preview won’t update
Platforms cache aggressively. If you change the image and the old one keeps showing, run the link through the platform’s sharing or post-inspector tool to force a re-scrape, or give it time to refresh on its own.
Make one now
Open the Open Graph image generator, fill in your title, and export. If the post is about code, pair the card with a code screenshot inside the article.