Generate a placeholder image at exactly the size your layout needs.

Why use a placeholder image instead of an empty box?

A labelled image survives exports, prototypes, documents, and handoffs more reliably than a design-tool-only shape. It tells reviewers what belongs in the space, preserves the intended proportions, and makes missing assets obvious instead of looking like accidental whitespace.

Placeholders are useful for email templates, wireframes, CMS previews, documentation, development fixtures, and client approvals. They are temporary production aids, so the label should be practical: describe the asset role or dimensions rather than adding decorative copy.

How should placeholder dimensions be chosen?

Use the dimensions or aspect ratio expected by the final layout. A 600 by 300 image has a 2:1 ratio; replacing it with a square image later will either crop the artwork or change the layout height. Matching proportions early prevents avoidable rework.

For responsive email, the source image can be wider than its displayed size so it remains sharp when scaled down. Keep the width and height attributes aligned with the layout’s intended ratio, and test how the image behaves when the container narrows on mobile.

What does retina or 2x export mean?

A 2x export contains twice the pixels in each dimension but is displayed at the original CSS size. For example, a 300 by 150 slot can use a 600 by 300 source image. This can look sharper on high-density screens while preserving the same layout proportions.

Retina export also increases file size, so it is not automatically the right choice for every email asset. Use realistic final optimization settings and avoid using a large placeholder as evidence that the eventual production image will meet performance requirements.

What should happen before placeholders reach production?

Search the final design and exported HTML for placeholder labels, temporary filenames, and generic alt text. Replace each asset with optimized final artwork and write alt text based on the image’s purpose. Decorative images can use empty alt text, while meaningful images need a useful text alternative.

The free generator makes temporary assets consistent and easy to recognize. A launch checklist should still treat every placeholder as unfinished content, even when it looks polished enough to pass a quick visual review.

• Replace temporary filenames and URLs.
• Confirm the final crop at desktop and mobile widths.
• Optimize the final file rather than the placeholder.
• Check alt text and linked-image destinations.