How to Make a PDF Smaller
By PDFOak · Published September 9, 2026 · Updated October 1, 2026
First find out what is taking up space. Scans, photo-heavy brochures, and exported text documents need different fixes.
Start with the least destructive change, and move toward a size target only if something outside your control enforces one.
Quick diagnosis
- Check the size, the page count, and whether the text is selectable.
- Remove pages that are duplicates or not needed.
- Try a lossless rewrite.
- For scans, set the real byte limit and read the rasterization warning if one appears.
- Open the result and compare it with the original.
If it is a scan
A scan is a photograph in a PDF wrapper, so real savings mean changing resolution or image encoding. Use exact-size compression with the limit you actually need, then check the small print.
If it is an exported document
Text documents exported from office software often carry fonts, repeated resources and untidy structure. A lossless pass can shrink these a lot and keeps the text.
If it is photo-heavy
A brochure with large photographs behaves like a scan even when its headings are selectable, because the images dominate the size. Replacing the images with smaller ones at the source often works better than compressing the PDF afterwards.
If the recipient accepts several files
Splitting an appendix from the main document keeps every page sharp. Name the parts clearly so the recipient can put them back in order.
Frequently asked questions
Will deleting pages make the file smaller?
Not reliably. PDFOak’s Delete Pages can leave the removed pages’ images inside the file. Extract Pages builds a new file from the pages you keep, so it is the one that shrinks it.