One small frontend optimization saved us from sending thousands of unnecessary megabytes to the backend

For a long time I treated image uploads as a backend problem.

Then I realized most of the files arriving at the server were much larger than the application actually needed.

Moving compression to the browser turned out to be surprisingly effective. Uploads felt faster, bandwidth dropped, and the backend stopped spending time processing oversized images that users would never notice anyway.

It reminded me how often we optimize infrastructure before questioning where the work should happen in the first place.

I packaged the approach into a small tool while building a few projects, but the interesting part for me wasn't the tool itself. It was realizing that changing where a task happens can matter more than making the task itself faster.

Has anyone else found frontend changes that ended up having a much bigger backend impact than expected?