Reviewed 2026-10-10
Set the shape before choosing the pixel count
Aspect ratio describes shape: 1:1 is square, 16:9 is wide and 9:16 is tall. It does not state how many pixels the file contains. Choose the ratio closest to the final placement so an important subject will not be removed by a later crop.
For a wide header, reserve the text-safe area in the brief and test how the image crops on a phone. For a product card, centre the item with enough space around the edges. Check the destination’s current upload requirements rather than assuming one export serves every placement.
Check actual dimensions, not just “1K” or “4K”
Download the file and inspect width and height in pixels. A resolution preset can produce different dimensions for different aspect ratios or providers. Increasing a display density tag does not add missing pixel detail.
For a print example, a 6-by-4-inch image at 300 pixels per inch needs 1800 by 1200 pixels before bleed. The printer may specify a different density, colour workflow or margin. Confirm those requirements first; exporting a file labelled “4K” does not by itself make it print-ready.
Choose the format for the content
JPEG is a common choice for photographic web images when transparency is unnecessary. PNG can preserve transparency and sharp graphic edges, while WebP can suit web delivery where the destination supports it. Inspect the exported file after compression, especially around small lettering and high-contrast edges.
When transparency matters, confirm an alpha channel and place the asset over two different background colours. A plain white background or a rendered checkerboard is not an actual transparent export. Select only formats available for the live endpoint, then make any needed finishing conversion in a suitable tool.
Keep an original and test the final crop
Save the largest accepted original before resizing. Create separate delivery files for each placement, giving them clear names such as product-square and header-wide. Review the final crop at its intended display size and ensure text, faces and product edges remain intact.
After uploading, inspect the actual published image; a platform may resize or recompress it. Keep the source, prompt, model and export settings so you can prepare a different size without losing the approved version. Request higher resolution only when the use case and current quote justify it.
Questions before you start
Will changing DPI make a small image sharper?
Changing the density metadata does not create new image detail. Check pixel dimensions and the intended physical print size.
Do I always need the highest resolution?
No. Choose dimensions sufficient for the final placement, inspect the result and consider the quote. Preserve an accepted original for later exports.