How to Compress PDF
- Choose one readable PDF.
- Review the available settings and start local processing.
- Review the result and download the .pdf file.
Compress a PDF Online for Free
Reduce PDF file size in your browser, choose an appropriate compression level, and review the size-versus-quality result before downloading the new copy.
or drop the file here
Up to 50 MiB per PDF
Up to 100 pages
Files remain in your browser
No file upload
No account required
Browser processing questions
How can I reduce a PDF file size?
Upload the PDF, choose a compression level, compress the document, and download the smaller result.
Does PDF compression reduce quality?
Stronger compression can reduce visual quality. Use a lighter setting when clarity is more important than achieving the smallest possible file.
Can PDFKaka compress a PDF to exactly 100KB?
Standard compression reduces file size but does not guarantee an exact final byte size unless a dedicated target-size mode is available.
Are my PDF files uploaded to a server?
No. Compression is processed in your browser.
Need another document task? Browse all working tools.
About this tool
Reduce PDF size with a compression level that fits the document
Compress PDF first tries a structure-preserving pass that keeps selectable text and interactive content where possible. Stronger modes rebuild pages as compressed images when a smaller visual copy is more important.
Useful for
- Try safe compression without intentionally rasterizing the pages.
- Prepare a PDF for an upload-size restriction.
- Use stronger image-based compression for scanned or photo-heavy documents when needed.
Good to know
- Recommended compression keeps document structure wherever possible.
- Strong and Maximum modes rebuild pages as images, reducing quality and removing selectable text, links, forms, accessibility data, and signatures.
- Some already compact PDFs will not produce a useful smaller result.
Practical guidance
Reduce PDF file size with a suitable compression level
PDFKaka first offers structure-preserving compression for documents where selectable text and interactive features matter. Stronger image-based modes are available for scanned or image-heavy files, but no mode promises an exact final size. The result depends on page count, dimensions, colours, and source content.
Start with structure-preserving compression
Recommended compression safely rewrites the document structure without intentionally turning every page into an image. It publishes a result only when the output is meaningfully smaller.
Use stronger compression for image-heavy files
Strong and Maximum modes render pages as compressed images. They can reduce scans more substantially, but fine print, signatures, diagrams, and identification details may become harder to read.
Understand what compression changes
Recommended mode keeps selectable text and document features where possible. Stronger image-based modes do not retain selectable text, links, forms, accessibility data, or signatures, so keep the original PDF.
Questions people ask about this task
Can PDFKaka compress a PDF to exactly 100KB?
Standard compression reduces file size but does not guarantee an exact final byte size. Check the downloaded result against the upload limit.
Why did my text-only PDF not become much smaller?
Digitally created text PDFs can already be compact. Recommended compression will not publish a larger or negligibly smaller copy just to claim success.
Are my PDF files uploaded to a server?
No. Compression is processed in your browser.
PDFKaka Guides
Practical PDF guides for complete tasks
Start with the result you need, then follow an honest workflow across the right browser tools.
Compress PDF guides
How to compress a PDF on iPhone or Android
Choose a PDF from phone storage, use a conservative compression level first, and save the smaller copy locally.
Compress PDF guides
How to compress PDF toward 100KB, 200KB, or 500KB
Reduce a suitable image-heavy PDF toward a portal limit while treating 100KB, 200KB, or 500KB as a maximum rather than a guaranteed exact result.
Compress PDF guides
How to compress PDF without making text unreadable
Start with a moderate image-quality setting and lower it only when the result remains above the required limit.
Compress PDF guides
How to reduce the size of a scanned PDF
Compress scanned or photo-heavy pages where image quality can be traded carefully for a smaller document.
Compress PDF guides
Why a PDF Will Not Compress Much — and What You Can Do
Some PDFs are already highly compressed, contain mostly text, or use images that have little additional size to remove. In those cases, another compression pass may produce only a small reduction.