PDF Compressor — Reduce PDF Size Online Free
Shrink your PDF file size by up to 80%. Choose a compression level, drop your file, and download the compressed PDF instantly. Everything runs in your browser — nothing is uploaded to any server.
Why Compress PDFs Without Uploading?
Most online PDF compressors — Smallpdf, ILovePDF, ilovepdf.com — upload your file to a remote server. Your confidential documents travel over the internet and are stored on third-party infrastructure, often for 24 hours or more.
This tool compresses entirely in your browser. Your file is never transmitted anywhere. This matters for:
- Legal contracts — NDAs, lease agreements, employment letters
- Financial statements — bank statements, salary slips, ITR
- Medical records — discharge summaries, prescription PDFs
- Government ID documents — Aadhaar, PAN, passport scans
How to Compress a PDF
- Drop your PDF into the upload area or click to browse
- Choose a compression level — Light, Medium, or Maximum
- Click Compress & Download
- The compressed PDF downloads to your device automatically
Compression Modes Explained
Lossless — best for text PDFs
Uses pdf-lib to rebuild the PDF with compact cross-reference streams and removes redundant internal objects. No page content is touched — text stays fully selectable and visually identical to the original. Typically reduces file size by 5–20%.
Medium — best for scanned PDFs
Re-renders each page to a canvas at screen resolution (1×) and re-encodes as JPEG at 76% quality. Effective when the original PDF is made of scanned photographs of paper — those pages are already raster images and re-encoding them smaller actually works. On text-only PDFs, this mode automatically falls back to lossless.
Maximum — aggressive, scanned docs only
Renders at 80% scale with 58% JPEG quality — the smallest output achievable in the browser. Use only for scanned documents where file size is the priority. Fine detail and thin text strokes may soften. On text-only PDFs this mode also falls back to lossless automatically.
Common Use Cases for PDF Compression
Email Attachments With Size Limits
Gmail limits attachments to 25MB and Outlook to 20MB. If your scanned documents or reports exceed these limits, compress them before attaching.
Uploading to Government or Bank Portals
Many Indian government portals (EPFO, income tax, RERA) and bank applications cap document uploads at 1–5MB. Compress your scanned PDFs to meet these limits.
Saving Storage Space
Large scanned PDF archives consume significant storage on Google Drive, OneDrive, or local drives. Compressing documents you rarely edit frees up space without deleting them.
Frequently Asked Questions
Which compression mode should I choose?
Use Lossless for any PDF where text quality matters — reports, contracts, and digital documents. Use Medium or Maximum only for scanned PDFs (photos of paper documents) where every page is already a raster image and text selectability is not needed.
Why does Lossless compression only reduce a little?
Lossless mode cleans up the PDF's internal structure (cross-reference tables, dead objects). For a well-formed digital PDF this is typically 5–20%. If you need more reduction, try Medium mode — but only if your PDF contains scanned images rather than vector text.
Why does the compressed PDF sometimes end up larger than the original?
This happens when you use Medium or Maximum mode on a text-based PDF. Text in PDFs is stored as compact vector data. Re-rendering it as a JPEG image takes more space. The tool detects this and automatically falls back to the Lossless result instead of ever returning a larger file.
Will the compressed PDF have a watermark?
Never. The output is a clean PDF with no watermarks, no branding, and no added metadata.
Are my files uploaded to a server?
No. All compression happens entirely in your browser using PDF.js and pdf-lib. Your file never leaves your device.
What is the maximum file size supported?
Up to 50MB. Larger files are processed page by page, so the practical limit is your device's available RAM.
Need to merge PDFs instead? Use our PDF Merger. Want to split a PDF? PDF Splitter.