PDF Compressor — Guide

Compress PDF files online by recompressing embedded photos and rebuilding the file structure. Two levels, live before/after sizes, never larger than the original. Free, private, runs in your browser.

What it is and when to use it

There are two levers behind every PDF size. The image layer: scans, camera shots and inserted photos are usually stored as full-resolution JPEGs, so the tool decodes each one and re-encodes it at lower quality (and, on strong mode, a lower pixel cap). The structural layer: PDFs that went through several edit-save cycles, printer drivers or email forwards accumulate orphaned objects and bloated cross-reference tables — rebuilding the file drops that overhead. What the tool deliberately does not touch: the text and vector layer stays untouched, so letters remain selectable and sharp at any zoom, and lossless screenshots keep their quality. That is also why a text-heavy PDF may shrink only a little — there was simply little fat to cut, and in that case you get your original file back.

Shrinks a PDF by recompressing its embedded photos and rebuilding the file structure, with before/after sizes and a never-larger guarantee.

How to use it

  1. Select a PDF file
  2. Pick balanced or strong compression
  3. Run it and compare the sizes
  4. Download the result

Things that trip people up

  • If nothing can be saved the original file is returned unchanged — the output is never larger than the input
  • Text-only PDFs are already compact; the savings come from photos
  • Files stay on your device — nothing is uploaded

Questions people ask

Why did my PDF barely shrink?
Text and vector drawings are already extremely compact — one page of an article can be a few KB. Size accumulates in images, so a PDF without photos has almost nothing to squeeze. If you are fighting an upload or mailbox limit, splitting the document by page ranges is the alternative.
Will compression make my document look bad?
Balanced mode keeps images at screen quality and is fine for everyday documents. Strong mode softens photos noticeably at around 1200px — good for scans and receipts, not for print-ready work. Text never degrades, because it is not re-rendered.
Is it safe for confidential PDFs?
Yes. The whole pipeline runs inside your browser; the file never leaves the device and there is no upload step that could be intercepted.

Next steps

Open the PDF Compressor tool

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