Quick answer
A good Discover featured image uses a clear focal point, a safe 16:9 composition, and enough visual simplicity to read instantly on a phone. Size gets you into the conversation; composition determines whether the card still feels clickable.
Why this matters
Strong Discover images are usually built around one dominant subject, one dominant story, and a composition that survives downsizing. They do not ask the user to decode tiny labels or hunt for the point of the frame.
This is why the size guide only solves part of the problem. You also need the editorial judgment described in the main Discover guide and the metadata consistency covered in the og:image guide.
Composition rules that travel well across cards
Most teams do better with a few durable composition rules than with endless visual experimentation.
- Keep the main subject large enough to understand at a glance.
- Avoid text overlays unless the typography is genuinely large and essential.
- Leave breathing room around the focal point so the image still feels balanced after responsive crops.
- Use contrast intentionally so the subject does not disappear into a muddy background.
A repeatable featured image workflow
Editorial consistency comes from templates. When every new article starts from a known safe grid, you spend less time fixing avoidable visual issues after the fact.
- Start with a 16:9 template that reserves the center for the subject and the edges for safe breathing room.
- Choose an image that supports the article angle rather than a generic illustration of the category.
- Export above 1200px width and compress for mobile before publishing.
- Preview the final image at card scale before calling it approved.
Common mistakes
The worst-performing featured images usually fail because they try to say too much or because they were borrowed from a format meant for another channel.
- Using social graphics with heavy text as if they were ideal Discover cards.
- Placing multiple competing subjects inside one frame.
- Publishing a valid image size but a visually weak composition.
- Ignoring how the image reads on an actual phone before publishing.
Practical implementation note
DiscoverImg helps because it shortens the feedback loop between design and mobile preview. You can validate size and format quickly, but more importantly, you can keep asking whether the featured image still tells the right story at card scale.
After composition is locked, finalize the export in DiscoverImg Optimizer and keep the approved asset aligned with your Open Graph metadata.
Frequently asked questions
What makes a featured image good for Google Discover?
A good Discover image is large enough, compositionally clear, and visually strong on a fast-scrolling mobile feed.
Should I add text overlays to Discover images?
Only when they are absolutely necessary and large enough to remain readable. Most of the time, simpler compositions perform better.
Can I reuse my social graphics as featured images?
Sometimes, but many social graphics are too text-heavy or designed for different crop behavior. A dedicated editorial asset is often safer.
Why do some large images still look weak in Discover cards?
Because size is only one variable. Subject clarity, contrast, and composition determine whether the card feels compelling.
How can I preview the final card before publishing?
Use a workflow that includes both optimization and previewing, such as DiscoverImg, so you can inspect the image at realistic card scale.
