Compress PDF

Shrink PDFs by 60-90% in your browser — no upload, no watermark, no signup.

  • No upload
  • Browser-based
  • Free
  • No signup
  • PDF

🔒 Your PDF never leaves your browser. All rendering and compression happens locally. Best results on scanned / image-heavy PDFs (60-90% reduction). Text-only PDFs may not shrink or may become slightly larger.

Depends on the tool — client-side tools keep files on-device; server tools auto-delete files after processing.

How to use Compress PDF

  1. Drop a PDF (up to 100 MB) or click to choose one. Every byte stays in your browser — nothing gets uploaded.
  2. Pick a compression level: High for smallest files, Medium for a good balance, Low to preserve the most detail. Use Custom to fine-tune DPI and JPEG quality yourself.
  3. Click Compress PDF. Every page is rendered to a canvas, JPEG-encoded at your chosen quality, and reassembled into a smaller PDF.
  4. Check the before/after size, then download the compressed file. If the result is larger than the input, try Low or Custom with higher DPI — you probably started from a text-only PDF.

Common use cases

  • Email attachments. Most email servers cap attachments at 20-25 MB. Scanned contracts and reports often exceed that — Medium compression usually brings a 40 MB scan below 5 MB.
  • Loan and mortgage applications. Portals like Rocket Mortgage, Chase, and SoFi enforce hard PDF size limits. Compress before upload to avoid the 'file too large' rejection.
  • Web upload of tax forms. IRS, state DoR, and school FAFSA portals restrict PDF sizes. Compressing keeps everything readable while fitting under the cap.
  • Cloud storage savings. Compressing a folder of 100 scanned invoices from 8 MB each to 800 KB each frees 720 MB. Multiply across a business and it's real Dropbox / Drive money.
  • Sharing via WhatsApp / Slack / Teams. Messenger apps often reject or degrade large PDFs. A compressed version keeps quality high enough to read and small enough to send.

Tips

  • Scanned PDFs and image-heavy PDFs compress the most — often 60-90% smaller. Pure text PDFs may not shrink or may grow slightly (vector text becomes raster).
  • Medium (110 DPI, 72% JPEG) is the safe default for readable everyday documents.
  • For anything you'll print, use Low (150 DPI, 85%) — print quality is preserved.
  • For the smallest possible file (screen-only viewing), High (72 DPI, 55%) is aggressive but usually still readable.
  • Custom mode: DPI is the render resolution (72 = screen, 150 = decent print, 300 = high print). Quality is JPEG quality — below 50 the artifacts get visible.

Troubleshooting

Compressed file is bigger than the original.
Your input was probably a well-optimized text PDF. Raster compression can't help there. Try Low, or use a tool that only recompresses embedded images without rasterizing the whole page.
Text became blurry.
The DPI is too low for your reading distance. Try Low (150 DPI) or Custom with 200+ DPI.
Very large PDF crashes the browser.
Mobile Safari / low-memory devices struggle above 200 pages. On desktop, up to 1000 pages usually works. Split the PDF first with our Split PDF tool if needed.

Frequently asked questions

Is my PDF uploaded anywhere?
No. Every byte stays in your browser. The compression runs locally using pdf.js (render) and pdf-lib (rebuild). Nothing touches our server or any third party.
How much can it shrink my PDF?
For scanned documents and image-heavy PDFs, 60-90% reduction is normal. For pure vector text PDFs, it may not shrink or may grow slightly — those PDFs are already efficient.
Does it work with password-protected PDFs?
No — you need to unlock the PDF first (open it in your PDF reader, save a copy without a password), then compress.
What's the maximum file size?
100 MB. That's a browser memory limit — larger files typically hang the tab. Split the PDF first if you need to compress something bigger.
Will text stay searchable in the output?
No — text becomes part of the rasterized image, so it's no longer selectable or searchable. If you need searchable text after compression, use a tool that recompresses only embedded images without rasterizing.
Does it work on mobile?
Yes, on modern mobile browsers. Very large PDFs (100+ pages, 50+ MB) may run out of memory on older phones — try Split PDF first.