Compress PDF
Compress PDF files by removing metadata and unused objects in your browser
How does this PDF compressor work?
This tool offers two compression modes. Lossless mode re-serializes the PDF structure using pdf-lib, removing metadata and compressing streams without altering content. Lossy mode renders each page as a JPEG image using pdf.js and rebuilds the PDF, achieving much higher compression at the cost of text selectability. All processing happens entirely in your browser.
What is the difference between lossless and lossy compression?
Lossless compression reduces file size by optimizing the PDF structure (removing unused objects, compressing streams, stripping metadata). It preserves text selectability and exact visual fidelity, typically reducing size by 10-30%. Lossy compression rasterizes each page into a JPEG image (2x scale, 80% quality), which can reduce size by 50-80% or more, but text will no longer be selectable or searchable.
Is my data safe?
Yes, all PDF compression is performed locally in your browser. No files are uploaded to any server. Your documents remain completely private and are never transmitted over the internet.
How much can I reduce my PDF file size?
It depends on the mode and content. Lossless compression typically achieves 10-30% reduction, with greater savings on files containing redundant metadata or uncompressed streams. Lossy compression can reduce file size by 50-80% or more, especially for PDFs with embedded images or complex vector graphics.
Will compression affect PDF quality?
Lossless mode preserves exact visual quality and text selectability. Lossy mode converts pages to JPEG images at 2x scale and 80% quality, which introduces slight compression artifacts but maintains good readability. The main trade-off in lossy mode is that text becomes non-selectable and non-searchable.
What does "Remove metadata" do?
It strips document metadata fields including author, title, subject, keywords, creator, and producer. This information is not visible in the page content but contributes to file size and may contain sensitive information such as author names or editing history.
What does "Optimize for fast web viewing" do?
This option linearizes the PDF file, reorganizing its internal structure so that the first page can be displayed before the entire file is downloaded. This significantly improves loading speed when viewing PDFs in a web browser, especially for large documents.
Can I compress multiple PDF files at once?
Yes, you can upload multiple PDF files simultaneously. After compression, all files are packaged into a single ZIP archive for convenient download. A re-download button is also available if you need to download the ZIP again without re-processing.