How to compress a PDF without turning the text into a photo
Try a lossless re-save first. Only rasterise pages to JPEG when the file is still too large — and know that text then becomes an image.
Updated 2026-09-21
A “compressed PDF” can mean two completely different files. One is the same document with unused objects dropped and streams packed — text stays sharp and selectable. The other is every page photographed as a JPEG, which shrinks scans and photo-heavy decks but destroys searchable text.
Batonbox Compress PDF exposes both. Lossless is the default. The strong mode re-renders pages as JPEG at 72, 110 or 150 dpi. That second path is honest about the trade: smaller file, text becomes a picture.
Start lossless
Many exports from slide software or a printer driver carry leftover objects, uncompressed streams and unused fonts. A lossless re-save often cuts 10 to 40 percent with no visible change. If that lands under your email or portal limit, stop there.
Lossless cannot invent a smaller photograph. A 20-megapixel scan embedded at full size will still dominate the file. That is when the image mode exists.
When image mode is the right hammer
Use it for scanned books, photo lookbooks, and slide decks that are already pictures of slides. Pick 150 dpi if someone will print; 110 dpi for screen reading; 72 dpi only when a form will reject anything larger and you accept the mush.
Quality around 0.6 is a sensible start. Lower than 0.4 starts to posterise faces and fine type. Remember: once text is a JPEG, you cannot copy a paragraph out of the result.
What compression will not fix
A 400-page report with vector drawings and a live table of contents should stay lossless or be split. Password-protected files need unlocking first. If you still need a much smaller file after a strong pass, extract the chapters you actually send.
Step by step
- 1
Run lossless once
Compare the new size to the original. If it is small enough, you are done and the text is still text.
- 2
Only then try images
Start at 110 dpi and quality 0.6. Check a page of type and a photograph before you go lower.
- 3
Open the result as a reader would
Zoom to 125 percent on a paragraph. If the letters look like a screenshot of a screenshot, raise dpi.
- 4
Keep the original
The strong mode is a one-way trip. Archive the source PDF; send the small copy.
Questions
- Does Compress PDF upload my file?
- No. Both modes run in the browser (pdf-lib for lossless, pdf.js plus canvas for the image pass).
- Why did lossless barely change the size?
- The file was already packed, or almost all of its weight is large embedded images. Use the image mode or split the document.
- Can I compress a PDF and still search the text?
- Yes after lossless. No after the image mode — the words are pixels.