Browser-based QPDF compression
The tool rebuilds PDF object and stream structures using the QPDF WebAssembly engine.
Compress PDF
Choose a PDF file
Processing is performed by the browser-based PDF engine.
Choose a PDF file to begin.
Compress PDF files directly in your browser with QPDF-based stream and object compression, then download the smaller PDF when size reduction is possible.
Browse PDF toolsFree browser toolNo account requiredPDF → PDF
Built around the task
Why use Compress PDF?
The page stays focused on the problem you came to solve, with the useful details directly around the tool instead of getting in your way.
Choose a compression level
Low, medium, and high settings control stream recompression effort without rasterizing every page.
No fake savings
If the PDF cannot actually be made smaller, the tool reports that instead of returning a larger file as a compressed result.
Three simple steps
How to use Compress PDF
Start with the document or text you already have, complete the task, and leave with a usable result.
Add PDF
Choose Files or add the content you want to work with.
Run Compress PDF
Reduce PDF file size
Use PDF
Review the result, download it, or continue into a related workflow.
Reduce PDF file size
Compress PDF files directly in your browser with QPDF-based stream and object compression, then download the smaller PDF when size reduction is possible.
Know what goes in and comes out
Clear file and output expectations help you choose the right tool before you start.
PDF inputPDF output
A simpler way to finish the job
About Compress PDF
Compress PDF is built around one clear outcome: reduce PDF file size. If you already have PDF and need PDF, this page keeps the action, the explanation, and the next useful steps together. You do not have to dig through a large software menu just to find the feature you came for. Start with the tool above, complete the task, review the result, and continue only when your document actually needs another step.
When Compress PDF is useful
Compress PDF focuses on one document job rather than surrounding it with unrelated features. That matters when you are trying to finish a small but necessary step quickly. Bring in the supported file or content, complete the task, review what changed, and then download the result or continue into a related workflow. The page is structured so the main action remains obvious from the moment you arrive.
Typical uses include preparing PDFs for email, forms, school or office submissions, document archives, client handoffs, printing, and workflows where a PDF needs to be edited, organized, converted, reduced, protected, or made easier to share.
Tips for better results
For PDF files, start with the cleanest source you have. Password protection, damaged files, unusual embedded fonts, very large scans, or image-only pages can affect what any browser-based PDF workflow can read or change. If the document is a scan and you need selectable text, an OCR step may be more appropriate before editing or converting.
Before downloading or sharing the finished file, give the result a quick review. Check the pages, text, images, order, formatting, or file size that matter for your task. If the output is not what you expected, go back to the source file and make sure it is the right version and format before trying again.
Continue the workflow without starting over
Document work rarely ends with one action. After reduce PDF file size, you may need another closely related step. You can use Edit PDF when you need to edit a PDF online. For a different next step, Merge PDF helps you combine multiple PDF files into one PDF. You can also move to Protect PDF to add password protection to a PDF. If your goal changes, Split PDF is available for split or extract pages from a PDF.
If none of those matches what you need, browse the PDF tools collection for tools that work with the same document family, or open the complete document tools directory to find another workflow by task or file type. These contextual links are intentionally placed around the current job so every tool page can act as both a useful destination and a sensible next step in the wider document workflow.
Compress PDF FAQs
Quick answers to common questions about this workflow.
How do I reduce PDF file size?
Choose a PDF, select a compression level, then run Compress PDF. A download appears only when the resulting file is smaller.
Does compression lower image quality?
This compressor focuses on PDF object and stream compression. It does not intentionally rasterize every page at a lower image resolution.
Why can some PDFs not be compressed further?
Some PDFs are already optimized or mostly contain data that QPDF cannot reduce without destructive recompression.