You export a small image for a website, then use that copy to make an even smaller one. Repeating this workflow can make it harder to judge which changes came from resizing and which came from compression.
Keep the source distinct
Lossy compression removes information to reduce data size. Re-encoding an already lossy image can introduce further changes, depending on the format, settings and operation.
Simply copying a file does not recompress it. The issue concerns operations that decode and encode the image again, not moving the unchanged bytes to another folder.
Make comparison exports
Start from the best available editable source and create separately named outputs. Compare two reasonable settings at the size readers will actually see. Inspect text edges, gradients and fine detail.
A smaller file is useful only if it still serves the image’s purpose. Keep the dimensions appropriate instead of relying entirely on an aggressive quality reduction.
Record the chosen version
Note output dimensions, format and file size so that a later replacement follows the same target. Do not overwrite the working source with the smallest delivery copy.
Use our format guide alongside this workflow. A controlled export makes the trade-off visible and avoids accumulating unexplained changes across a chain of compressed copies.