Free PDF Compressor
Compress PDF online free and reduce PDF size for email, uploads, forms, and document portals.
Make large PDFs smaller by optimizing images while preserving text, fonts, and layout. No signup, no watermark.
HTTPS Upload
Encrypted transfer
No PDF Storage
Deleted after processing
No Signup
Free to use
Up to 50 MB
PDF file uploads
1. Upload your PDF
Choose a PDF file up to 50 MB. Image-heavy PDFs like scans, catalogs, slide decks, and reports with photos usually shrink the most.
Drop your PDF here
or choose a file from your device
2. Choose compression level
Start with Medium for most PDFs. Use Lossless when quality matters most, or High when you need the smallest file.
How to Compress a PDF Online for Free
Upload your PDF, choose a compression level, and download a smaller PDF file. No signup, no watermark.
1. Upload Your PDF File
Choose an existing PDF up to 50 MB. Image-heavy PDFs like scans, catalogs, reports, and slide decks shrink the most. Password-protected PDFs are not supported.
2. Choose a PDF Compression Level
Start with Medium for most PDFs, use Lossless for best quality, or choose High when you need the smallest PDF file.
3. Download the Compressed PDF
After compression, check the original size, output size, and reduction percentage, then download the smaller PDF.
Why Use PDFBolt's Free PDF Compressor
Reduce PDF size online with clear compression levels and privacy-focused processing.
Works best for existing PDFs like scans, reports, catalogs, and slide decks.
Compress Existing PDF Files
Upload a PDF you already have and reduce PDF file size online, without rebuilding the document or changing its original layout.
Clear Compression Levels
Choose Lossless, Low, Medium, or High depending on whether you need best quality, balanced compression, or the smallest PDF file.
Files Deleted After Processing
Your PDF is processed, returned, and deleted after compression. We do not store files or create public download links.
No Signup or Watermark
Compress PDFs online free without creating an account, adding a watermark, installing desktop software, or using additional tools.
PDF Compression Tips for Better Results
Different PDFs compress differently. Image-heavy files usually shrink most, while text-only, print-sensitive, or already optimized PDFs may need a different compression level.
Scanned PDFs and Photo-Heavy Reports
Scans, catalogs, slide decks, and photo-heavy reports often include large embedded images that give PDF compression more room to work.
Need to compress PDF for email, forms, or upload portals? Use Medium first. If the file is still too large, try High for a smaller PDF.
Text-Only PDFs
Text, vector graphics, and embedded fonts are already compact compared with raster images.
Use Lossless or Low. A small reduction is normal when a PDF has few images or mostly text.
Quality-Sensitive PDFs
Photos, gradients, and detailed artwork can show artifacts after aggressive image compression.
Use Lossless or Low for client-facing, design-heavy, or print PDFs. For PDF/X preparation, use the free PDF/X converter.
Already Optimized PDFs
Files compressed by another tool may have little room left to reduce, especially when images are already optimized.
Try High only if you need the smallest file. If compression would increase file size, we return the original PDF instead.
Frequently Asked Questions
Common questions about reducing PDF size online, compression quality, target sizes, file privacy, passwords, digital signatures, and API automation.
How do I make a PDF smaller?
Is this PDF compressor really free?
Is this PDF compressor safe, and do you store uploaded PDFs?
Which compression level should I choose?
Can I compress a PDF without losing quality?
Can I compress a PDF to 1MB, 500KB, or 100KB?
Why is my compressed PDF still large?
Can I compress password-protected PDFs?
Can I compress signed PDFs?
Can I automate PDF compression with an API?