: A dedicated freeware tool that offers five different compression presets, ranging from "Screen" (72 dpi) to "Prepress" (300 dpi). It is extremely simple to use: just select your file, choose a setting, and hit "Compress".

If you need an offline solution that respects the system constraints of older PCs, these programs are verified to work:

: Look for tools that let you choose the output quality (e.g., eBook vs. Print) to balance file size and readability.