In this guide
- Keep the master separate from the delivery file
- Use JPEG thoughtfully for photographic delivery
- Use PNG when lossless edges or transparency matter
- Reserve WebP for destinations that support it
- Separate pixels, file size and print resolution
- Build an export recipe for each destination
- Inspect the delivered and published versions
A product image can be sharp in Photoshop, soft in a messaging preview and full of compression marks after someone saves it again. The file extension is only one part of that story. Pixel dimensions, compression, colour handling and the number of export steps all affect the result.
The safest workflow separates three jobs: the editable master, the final marketplace upload and the lightweight image used on your own website. They may come from the same photograph, but they do not always need the same format. This guide explains the practical differences without pretending that one extension guarantees quality or platform acceptance.
Keep the master separate from the delivery file
Retain the original capture and a high-quality editable master. A layered editing file can preserve masks, text and adjustments; the marketplace upload is usually a flattened delivery asset. Reopening and editing a small final JPEG should not become the normal way to create the next version.
Organise files by SKU, purpose and revision. For example, keep “main”, “dimensions”, “contents” and “lifestyle” exports in a delivery folder, with the source work elsewhere. A filename that identifies the actual variant is more useful than “final-final-new”. Keep a simple approval note so the person uploading knows which revision is current.
When handing a project to another designer, include source photographs and editable artwork as agreed, plus the approved export specifications. File-format problems often start as handoff problems: someone receives a compressed preview and assumes it is the original production asset.
Use JPEG thoughtfully for photographic delivery
JPEG uses lossy compression. That means it can reduce file size by discarding some image information. At sensible export settings it works well for many photographs, but excessive compression can produce blocky areas, muddy texture and halos around high-contrast edges.
Inspect the most demanding part of your image: a small label, a diagonal line, a patterned fabric or a bright edge against a dark surface. A thumbnail may hide the damage. Review the final file at its actual pixel size as well as at the size a shopper will normally see.
Avoid repeatedly editing and saving the same delivery JPEG. Return to the master, make the change and export once. Quality numbers are not universal between applications, so treat a slider value as a starting point rather than a specification that guarantees the same visual result everywhere.
Use PNG when lossless edges or transparency matter
PNG supports lossless compression and transparency. It can be useful for working cut-outs, interface graphics and artwork with crisp text or flat shapes. However, a photographic PNG can be much larger than a comparable JPEG, and a transparent canvas is not automatically appropriate for a final marketplace image.
If you need a pure white background for a main-image upload, create and inspect that background deliberately. Transparency can appear white in one viewer and dark in another. Do not assume the upload system will flatten an alpha channel exactly as you intended.
Check transparent edges against both light and dark temporary backgrounds. A cut-out that looks clean on white may have a pale fringe on a darker layout. Preserve a clean working asset, then flatten it against the intended final background when making the delivery version.
Adobe’s JPEG and PNG comparison explains the different compression and transparency characteristics. The useful choice depends on the image’s content and destination, rather than whether one file sounds more professional.
Reserve WebP for destinations that support it
WebP supports both lossy and lossless encoding and can include transparency. It is often useful for fast website delivery, such as blog thumbnails and product previews. That does not mean you should assume it is accepted by every marketplace upload field or every older editing tool.
Google’s WebP documentation describes the format’s web-focused capabilities. Use WebP for your own site when your stack supports it and you have checked the output. For Amazon uploads, follow the current accepted-format list in Seller Central instead of using your website’s format as the default.
If you download a WebP preview and need a different upload format, convert it properly using an image editor or conversion tool. Renaming “.webp” to “.jpg” does not change the encoded image. Wherever possible, export the required file directly from the original master rather than converting a previously compressed preview.
Separate pixels, file size and print resolution
Pixel dimensions describe how many pixels the image contains. File size describes how much storage the encoded file occupies. A print-resolution label such as 300 ppi does not create extra detail in a small image. Changing that label alone will not turn a blurry photograph into a sharp zoomable asset.
Upscaling can increase pixel dimensions but cannot guarantee faithful recovery of missing product detail. AI upscaling may invent label shapes, fabric texture or small features. Compare enlarged output with a real reference and never use invented detail as evidence of a material or specification.
| Property | What it tells you | What it does not guarantee |
|---|---|---|
| Pixel dimensions | Image width and height in pixels | Accurate focus or real source detail |
| File size | Storage and transfer amount | Better quality simply because it is larger |
| Format | Encoding and supported features | Acceptance by every destination |
| PPI metadata | A print-scaling instruction | Additional pixels or sharper web display |
Build an export recipe for each destination
Write a short preset note for marketplace images and a separate one for your website. Include the required pixel dimensions, aspect ratio, accepted formats, colour workflow and any file-size limit shown by the actual destination. Recheck platform requirements when starting a new project rather than relying on a years-old cheat sheet.
Amazon’s public product photography guide discusses upload formats and links to Seller Central requirements. Use the current official product image requirements as the final authority for your category and marketplace. The rules for an A+ module can differ from a gallery-image upload.
For images containing text, export a test early. Look at the label and headline after resizing. If they fail, improve the design or source quality before searching for a magical format. The image copywriting guide explains why readable wording begins with hierarchy and restraint.
Inspect the delivered and published versions
Open the final export in an ordinary viewer and confirm that it really is the expected type, dimensions and revision. Look for broken transparency, colour shifts, unexpected borders and cropped edges. Review every image in a set; one old file can undermine an otherwise consistent gallery.
- Correct SKU and approved revision.
- Actual encoding matches the extension.
- Pixel dimensions and format match the destination.
- Important labels remain sharp.
- Background and transparency behave as intended.
- Colour is consistent with the master.
- Published output checked after upload processing.
Editorial photographs are credited beside each image. They illustrate the topic and do not represent ListingBrain customer results or an endorsement by a depicted person.