Compress PDF Online Free
Reduce your PDF file size instantly. Free, no signup, your file is processed entirely in your browser.
🔒 Your files never leave your browser. All processing is done locally.
Compression level
How to Compress a PDF File
- 1
Upload your PDF
Click the upload zone or drag and drop your PDF file. Your file stays on your device.
- 2
Choose a compression level
Select "Maximum" for the smallest file size, "Standard" for a good balance, or "Minimal" for best compatibility with older readers.
- 3
Compress and download
Click "Compress PDF". The tool shows you the before and after file sizes, then downloads the compressed PDF automatically.
Large PDF files cause problems at every step — slow email attachments, upload failures on web portals with strict size limits, and long load times when sharing links. want2convert's Compress PDF tool reduces file size directly in your browser, without sending your document to any server.
The tool re-saves your PDF using pdf-lib, which strips unused and redundant internal objects that accumulate when a document goes through multiple edits or is exported from an application that does not optimise its output. For the Maximum compression level, it also enables cross-reference object streams — a PDF 1.5 feature that packs the file's structural data using deflate compression, the same algorithm used by ZIP files.
How much will my file shrink? Results depend heavily on how the original PDF was created. A PDF from Word 2019 or Adobe Acrobat may already be well-optimised and shrink only a few percent. A PDF exported from an older tool, or assembled from many separate files, can shrink 20–40%. The before/after size comparison is shown immediately so you can decide whether the result meets your needs.
Does compression affect quality? No. This tool reorganises the internal structure of the PDF — it does not re-encode images, fonts, or text. Pages will look identical to the original when opened in any PDF reader.
If you need more aggressive size reduction, consider converting the PDF to images first using PDF to JPG and then recombining with JPG to PDF. Note that this approach trades image quality for size.