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Free PDF Compressor

Compress PDFs online for 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 a 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.

1. Upload Your PDF File

Choose an existing PDF up to 50 MB. Upload it from your device or drag it into the tool. 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.

Compress Existing PDF Files

Reduce your PDF file size by optimizing images while preserving text, fonts, and layout.

Clear Compression Levels

Choose Lossless, Low, Medium, or High to balance PDF file size and image quality.

Files Deleted After Processing

Your PDF is deleted after compression. We do not store files or create public download links.

No Signup or Watermark

Compress PDFs online for free. No account, watermark, or software installation required.

PDF Compression Tips for Better Results

Image-heavy PDFs usually shrink the most. For text-only PDFs, print documents, or already optimized files, choose a compression level that suits your quality requirements.

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.

Try this

For email attachments and upload limits, start with Medium. 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.

Try this

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.

Try this

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 not become much smaller, especially when images are already optimized.

Try this

Try High only if you need the smallest file. If compression does not reduce the file size, we return the original PDF.

Learn about PDF compression in the API

Frequently Asked Questions

Common questions about reducing PDF size online, compression quality, target sizes, file privacy, passwords, digital signatures, and API automation.

Upload your PDF, choose a compression level, and download the smaller PDF. This free PDF compressor works as a PDF size reducer: it can shrink PDF files by optimizing embedded images, repeated content, and PDF structure.
Yes. You can compress PDF files online for free with no signup, no watermark, and no credit card. Uploads are limited to 50 MB per PDF.
Uploaded PDFs are sent over HTTPS, processed server-side, and deleted after the compressed PDF is returned. We do not store your PDF file or create a public download link.
Use Medium for most PDFs. Use Lossless when quality matters most, Low for light size reduction, and High when you need the smallest file and can accept lower image quality.
Use Lossless for the highest image quality setting. Check images and fine details after compression, as results depend on your PDF.
The final size depends on your PDF and the compression level. Try High for stronger compression. You cannot set a target size, so reaching 1 MB, 500 KB, or 100 KB is not guaranteed.
PDF compression works best on image-heavy files such as scans, catalogs, slide decks, and reports with photos. Text-only PDFs, vector-heavy files, and PDFs already compressed by another tool may not become much smaller.
Password-protected PDFs are not supported.
You can upload signed PDFs, but changing the PDF bytes may invalidate existing digital signatures. Keep the original signed PDF if the signature matters.
Yes. Use the PDF Compression API to compress existing PDFs, or apply compression when generating PDFs from HTML, URLs, and templates with the Conversion API.

To compress more PDFs without writing code, create a free account and use the Playground with 50 monthly credits.

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Compress more PDFs

Create a free account and get 50 monthly credits to compress your PDFs in the Playground. You can also automate PDF compression with the API.

Try in Playground