Quick answer
The error message 'This file exceeds the maximum allowed size' usually means the website has a hard KB or MB limit and your file is above it.
The first step is to identify the actual limit. If the site does not show an exact number, common limits are 1MB, 2MB, or 5MB. Strict government and application portals can be as low as 200KB or 500KB.
What usually works best
Once you know the limit, aim slightly below it. If the limit is 1MB, targeting 950KB is often safer than landing exactly on the boundary, because some systems round file sizes differently.
For PDFs, this error often comes from high-resolution scans or images embedded in the document. A targeted PDF compressor lets you lower render scale and quality in a controlled way while checking readability.
If it still fails
For JPG and PNG images, the fix is usually a combination of compression and resizing. If a profile photo is rejected, reducing the dimensions before compressing can produce a cleaner result than forcing very low quality.
Exact-size compression helps because you do not have to test random outputs. You set the target, download the result, and only adjust format or dimensions if the website has another hidden rule.