WebP supports both lossy and lossless compression and can include transparency. It is useful for many web images, but the correct choice still depends on the image content, the receiving browser or application and the fallback strategy.
Choose WebP for a specific delivery need
Consider WebP when you control a web page and want a modern image format for photographs, graphics or transparent assets. Do not replace an archival original solely because WebP is smaller; keep a source format that suits editing and long-term storage.
Compare the same source
Use the same source image when comparing WebP with JPEG or PNG. Record dimensions, quality or lossless mode, output bytes, transparency and visible differences. A comparison is meaningful only when the source, target dimensions and inspection method are kept consistent.
Check compatibility
Confirm that the CMS, image pipeline and target browsers accept the output. When a fallback is needed, use a `picture` element or another delivery method that retains a normal `img` fallback. Verify the actual response and the rendered result rather than assuming that the file extension is enough.
Avoid the wrong conversion
A format conversion can change metadata, color handling or animation behavior. Inspect transparent edges, gradients, text and animated frames. If the output is used outside the browser, open it in that application before deleting the source.
Where WebP fits in a delivery stack
WebP can be a delivery copy while JPEG, PNG, TIFF or a design source remains the working original. The web copy should be generated after the target dimensions and visual requirements are known. Store the relationship between source and output so that later edits do not begin from a compressed derivative.
A compatibility test
Test the output in the target browser, CMS preview, download path and any application that consumes it. If a fallback is part of the implementation, request the page with a browser that does not support the preferred format or inspect the HTML and response path. A successful conversion alone does not prove that the published delivery works.
Record the trade-off
The useful WebP record includes the source format, target dimensions, chosen mode, output size, visible differences and compatibility result. This is enough to reproduce the decision later without presenting one conversion as a universal comparison.
Record the trade-off
The useful WebP record includes the source format, target dimensions, chosen mode, output size, visible differences and compatibility result. This is enough to reproduce the decision later without presenting one conversion as a universal comparison.
A practical fallback check
If the image is part of a page, inspect the final HTML and network request rather than only opening the downloaded file. Confirm that the preferred image is selected when supported and that the fallback remains usable when it is not. Record the browser, URL and result so the decision can be revisited after a deployment.
Sources and further reading
MDN’s image format guide documents WebP’s capabilities and browser considerations. web.dev’s image performance guide explains format selection, fallbacks and measurement.