Blog featured image size: the dimensions that work everywhere

You spend a day on an article, share it on LinkedIn, and the preview shows half a face and a cropped headline. The article was fine. The image was the wrong shape.

Your blog's featured image does more jobs than any other picture you make. It sits at the top of the article, it becomes the preview card when someone shares the link, and it can appear beside your result in search. A size that works for one of these often breaks another.

Here is a setup that works everywhere, and why.

The short answer

Make the featured image 1200 × 628 pixels (a ratio of about 1.91 to 1), keep the important part in the centre, and export it as a compressed JPEG or WebP under about 300 KB.

That shape matches the link-preview format used by most social platforms and messaging apps, so the image you designed is the image people see when the link is shared. Most blog themes will also crop it gracefully for the article header.

Why 1.91 to 1

When you share a link, the site's Open Graph image (the og:image tag) becomes the preview. LinkedIn, Facebook, X and WhatsApp all show link previews close to this wide format. If your featured image is square or tall, the platform crops it, and it usually crops the part you cared about.

Designing at the preview shape means the crop never surprises you.

The safe zone

Even at the right ratio, edges get trimmed. Some themes crop the header to a slimmer strip, some apps round the corners, and small previews shrink everything. Keep these inside the middle 80 per cent of the width and height:

• the subject (a face, a product, a hand on a page),
• any text you add to the image,
• your logo, if you use one.

Treat the outer edge as background that can disappear.

Text on the image: less than you think

A headline on the image looks good large and unreadable small. Link previews on phones are often the width of a thumb. If you add text, keep it to a few words, set it large, and make sure the article title still makes sense without it, because many previews show the title beneath the image anyway.

Never put text that matters in the image only. Search engines and screen readers cannot read it.

File size and format

Featured images are often the largest thing on a page, which makes them the main factor in how fast the page appears. A few habits help:

• Export at the size you need (1200 wide is plenty for most themes; offer a larger version only if your theme shows it full-width on big screens).
• Use WebP or AVIF where your platform supports them, with a JPEG fallback.
• Compress until you can see the difference, then go back one step.
• Set the width and height in the HTML so the page does not jump while the image loads.

Alt text that helps

Describe what the image shows, in a sentence, as you would to someone on the phone: "Two marketers comparing printed layouts at a long table." Do not stuff keywords into it. Alt text is for people who cannot see the image, and search engines read it the same way.

A checklist before you publish

1. 1200 × 628, subject in the middle 80 per cent.
2. Text on the image readable at thumbnail size, or no text at all.
3. Under about 300 KB, WebP or AVIF with a JPEG fallback.
4. Width and height set; alt text written.
5. The og:image tag points at it, so the share preview matches.
6. Paste the URL into LinkedIn's Post Inspector or Facebook's Sharing Debugger to see the preview before you announce the post.

How Wonib does it

Wonib's Blog images tool reads the article, finds what it is really about, and proposes three hero concepts in your brand. Each is checked for relevance to the article and for your brand's look, then exported at 1200 × 628 for the web. If you want to try it on your next post, start a free day.

Questions people ask

What size should a WordPress featured image be?

It depends on the theme, but 1200 × 628 works for most themes and matches link previews. If your theme shows the image full-width on large screens, export a larger version at the same shape, for example 2000 × 1047.

Does the featured image affect SEO?

Indirectly. A heavy image slows the page, and speed is part of how pages are judged. The image can also appear in image search, which is where descriptive file names and alt text help.

Should the featured image include the article title?

Only a few large words, if any. Most previews already show the title beneath the image, and small text becomes unreadable on phones.