What is a PDF Compressor?
A PDF compressor is a tool that shrinks a PDF's file size — often by 50% or more — without meaningfully affecting how the document looks or reads. It works mainly by re-encoding the images embedded inside the PDF at a lower resolution and reducing internal structural overhead, while leaving the text, layout, and page count untouched. Our tool lets you compress PDF online for free directly in your browser: no software to install, no account required, and every file is processed on our own servers rather than sent to a third-party service.
How to Compress a PDF Online — Step by Step
- Upload your PDF. Drag and drop your file into the box above, or click to browse and select one or more PDFs from your device.
- Choose a compression level. Use the quality slider to pick a balance between file size and image quality — lower for the smallest file, higher to preserve more detail.
- Compress and download. Click "Compress PDF." Once processing finishes, you'll see the new file size and percentage reduction — download the result with one click.
Why Use Our PDF Compressor?
- Free, unlimited use — no daily cap designed to push you toward a paid plan.
- Fast — most PDFs compress in a few seconds, even with multiple files at once (batch support).
- Private — files are processed on our own infrastructure only, and permanently deleted within 2 hours automatically.
- No signup required — guest use is fully supported for every tool on the site.
- Adjustable quality — you control the size-vs-quality trade-off instead of getting a one-size-fits-all result.
Frequently Asked Questions
Will compressing my PDF reduce its quality?▾
Some quality reduction is expected — that is how compression achieves a smaller file size, and it is controlled by the quality slider. At higher quality settings, the difference is usually unnoticeable for on-screen reading; at the lowest setting, images may look visibly softer.
Is there a file size limit?▾
Yes, PDFs up to 200 MB per file are supported, with no limit on how many files you can compress.
Do you store my PDF after compressing it?▾
No. Your uploaded file and the compressed result are stored only long enough for you to download it, and are automatically deleted within 2 hours either way.
Can I compress a password-protected PDF?▾
Not directly — remove the password first using our Unlock PDF tool, then compress the unlocked file.
Does this work on mobile?▾
Yes, the tool is fully responsive and works in any modern mobile browser, no app installation needed.
How much smaller will my file get?▾
It depends on the PDF — documents with many high-resolution images typically shrink the most (often 50-90%), while text-only PDFs that are already small will see a smaller reduction.
Related Tools
- Merge PDF — Combine multiple PDFs into one file.
- Merge PDF and Image — Combine PDFs and images into a single PDF.
- Split PDF — Split a PDF into separate files by page range.
- Crop PDF Page — Crop margins or content area from PDF pages.
- Organize PDF — Reorder, delete or duplicate PDF pages.
- Rotate PDF — Rotate one or all pages in a PDF.