Convert ARW to WebP

This is the first thing to establish and the thing most pages will not tell you. WebP is a published standard supported by every current browser, and on a site you control — Shopify, WooCommerce, Squarespace, a static site — it works with no configuration and no fallback. Uploading is not the problem there.

Marketplaces are different. Several large listing platforms specify JPEG or PNG in their image requirements and reject other formats at upload, sometimes with an unhelpful error. If you are listing on someone else’s platform, read the image requirements first and use the JPG route if WebP is not on the list. Converting four hundred product shots and then discovering this is an expensive way to learn it.

For the same visible quality WebP typically comes in a quarter to a third smaller than JPEG. A category page with forty product thumbnails and a hero image is carrying a lot of picture, and on a phone over a mobile connection that saving is the difference between a page that feels responsive and one that does not.

It also lands on the metric that matters commercially. The Largest Contentful Paint on a product page is nearly always the product photograph, and that is the element being measured. Reducing its size is the most direct lever available without redesigning anything.

A Sony Alpha preview is the full sensor width — 6,000 pixels on a 24-megapixel A7 III, 9,504 on a 61-megapixel A7R IV. A product tile might display at 400 pixels and a zoom view at 2,000. Everything above that is downloaded and discarded.

Set a maximum width during the conversion rather than after it. Cutting 6,000 pixels to 2,000 removes about nine-tenths of the pixel count, which saves an order of magnitude more than any quality setting will, and costs nothing a customer can see.

The picture is compressed by the camera when it writes the preview into the ARW, and again when this converter re-encodes it as WebP. That is two lossy passes, and at the default quality of 82 at store dimensions it is not visible.

Many platforms then re-encode the upload into their own derivatives, which is a third. That chain is the reason to convert from the ARW every time rather than from an image you exported earlier, and the reason not to shave the quality setting down as well — the passes you do not control will take their share regardless.

A customer who receives a jumper in a different blue from the listing photograph opens a return, and that is a cost no page-weight saving covers. The extracted preview carries the white balance the camera chose, and auto white balance under mixed lighting is exactly where cameras get colour wrong.

This is the case where going back to the ARW earns its keep. Develop the raw with a fixed white balance, or better, shoot a grey card and set it, and export from there. Extraction is the fast path for the twenty situation shots; the product on white deserves the careful path.

The re-encode drops the EXIF completely — no camera model, no lens, no timestamp, no GPS coordinate. Product photographs are very often taken at home or in a workshop, on a body paired with a phone that supplies location, and a listing image carrying those coordinates is a privacy problem published at scale.

It also removes the capture timestamps, which quietly stops a listing from advertising that its photographs are three years old. Neither of these is a reason to convert on its own; both are worth knowing you get.

The output takes the source name, so DSC01847.ARW becomes DSC01847.webp. On a store that filename is one of the few pieces of text attached to the image, and a camera serial number tells a search engine nothing about the product.

Rename to something descriptive before uploading and write real alt text. On a product page those two things influence how the image is found more than the choice of format does.

Drop the whole selection, apply one maximum width across the set, and take the result as a ZIP. Consistency matters on a storefront in a way it does not elsewhere — tiles that were converted at different widths look wrong next to each other on a grid.

The free tier accepts input files up to 100 MB, which covers compressed and lossless compressed ARW files comfortably. An uncompressed 61-megapixel frame at around 120 MB is over the limit, and is more file than a product listing has any use for.

The whole conversion runs in your browser: the ARW files are read locally, scanned locally and written locally. For photographs of a product that has not launched, a prototype, or anything under an agreement with a supplier, that is the difference between a tool and a leak.

It is checkable. Open the developer tools, watch the network tab while a file converts, and see that nothing carrying the image is sent — or disconnect the machine and convert anyway.