PDF Compressor
Shrink a PDF by re-encoding its embedded images at a quality level you choose — entirely in your browser. Best for image-heavy PDFs like scans, brochures, and slide decks. Uses PDF.js + pdf-lib.
Drop a PDF here
Or click to choose. Stays on your device.
Choose PDFHow it works: each page is rasterized at the chosen DPI and re-embedded as a JPEG. This shrinks image-heavy PDFs (scans, brochures, slide decks) by 50–80%. Text-only PDFs are already compressed efficiently — if the re-encode would grow them, the original is returned untouched.
What you'll use this for
Email-friendly size
Squeeze a 30 MB scanned PDF below the typical 10 MB email attachment cap.
Upload to gated portals
Get a PDF under the size limits of tax, immigration, and university portals.
Mobile sharing
Reduce a large brochure for fast sharing over WhatsApp or Telegram.
Archive a stack
Lower DPI for long-term storage of read-only documents.
How to compress a PDF
Drop in a PDF
One PDF at a time. Page count and size are parsed locally.
Pick a quality preset
Low for the smallest file, Medium for a balanced result, High to stay close to the original look.
Optionally cap the DPI
150 DPI is the sweet spot for screen reading; 72 DPI for the most aggressive shrink.
Click Compress and download
A new PDF is generated locally and offered as a download. Original stays untouched.
Frequently asked questions
No. Compression runs in your browser. Page bytes never leave your device.
Yes — this version rasterizes each page as a JPEG. The output is image-only, so OCR or text search no longer works on it. For text-heavy PDFs, this isn’t the right tool.
Scans and image-heavy PDFs typically shrink 50–80% at Medium. Text-only PDFs may grow rather than shrink — don’t use it for those.
Both are dropped during rasterization. Use the original if you need to keep them.
Full PDF object-graph rewriting is too complex for a quick browser tool. This version targets the common case: image-heavy PDFs, where a re-encode wins big.
About PDF compression
PDF compression has two flavors. Lossless compression rewrites streams and deduplicates objects — savings of 5–15%. Lossy compression re-encodes embedded images at lower quality, which can shrink scans by 50–80%. This tool focuses on the lossy path because it has the biggest impact.
How it works
- PDF.js renders each page at your chosen DPI onto a canvas.
- The canvas is encoded as a JPEG at the chosen quality.
- pdf-lib embeds the JPEG into a fresh PDF and adds the page.
Trade-offs
- The output is image-only. Searchable text becomes pixels — OCR is needed to make it searchable again.
- Annotations, bookmarks, and form fields are stripped.
- Best for scans, brochures, and presentations. Worst for contracts and text-heavy reports.