Free online PDF compressor
Compress PDFs to a fraction of the size
Compress PDF is a free tool that reduces PDF file size right in your browser. Pick a compression level, and download a smaller file in seconds. No signup, no upload — your documents stay on your device.
Drop your PDF, choose a quality level, and download the compressed result.
- 100% free
- No signup
- No upload
- Adjustable quality
- Up to 200 MB
Drop a PDF file here
or , or paste with Ctrl+V
Up to 200 MB
How to compress a PDF
Three steps — free, browser-based, and nothing to install.
Upload your PDF
Drag a PDF onto the drop zone, click to browse, or paste from the clipboard with Ctrl+V (⌘V on Mac). Files up to 200 MB are supported.
Pick a compression level
Choose Maximum compression for the smallest file, Balanced for a good tradeoff between size and quality, or High quality for mild compression that preserves sharp text and images.
Download the compressed PDF
Click Compress PDF and wait for processing to finish. The result shows the new file size and how much smaller it is. Hit Download to save it.
Technical specifications
| Input format | PDF — up to 200 MB |
|---|---|
| Output format | Compressed PDF (JPEG-encoded pages) |
| Compression levels | Maximum · Balanced · High quality |
| DPI range | 72 – 150 depending on compression level |
| Processing location | Your browser — files are never uploaded |
| Price | Free — no signup, no watermark, no file quota |
| Works offline | Yes, once the page has loaded |
Frequently asked questions
- How does the PDF compressor work?
- The tool renders each page of your PDF at a controlled resolution (DPI), re-encodes the page content as a compressed JPEG image, and reassembles everything into a new, smaller PDF. Lower DPI and quality settings mean a smaller file.
- Will compressing reduce the quality of my PDF?
- It depends on the level you choose. 'High quality' keeps images sharp and text readable — most people won't notice the difference. 'Maximum compression' prioritises file size over fidelity, which works well for email attachments or archival copies where pixel-perfect detail is not critical.
- Is there a file size limit?
- Each PDF can be up to 200 MB. Since compression runs entirely in your browser, there is no server-imposed upload cap — your device's memory is the only real constraint.
- How much smaller will my PDF get?
- Results vary by content. Image-heavy PDFs (scanned documents, photo portfolios) often shrink by 50–80%. PDFs that are mostly vector text may see a smaller reduction because the content is already compact.
- Does text stay selectable after compression?
- The compressed output is image-based, so text is no longer selectable or searchable. If you need to keep selectable text, this tool is best for scanned documents and image-heavy files where text selection is not a priority.
- Can I compress a password-protected PDF?
- The tool tries to open encrypted files, but heavily restricted PDFs may fail. If that happens, open the file in a PDF reader, save a copy without the password, and compress that copy instead.
- Are my files uploaded to a server?
- No. The entire compression process runs inside your browser using JavaScript. Your file never leaves your device — nothing is uploaded, stored, or logged.
- Can I compress multiple PDFs at once?
- Currently the tool handles one PDF at a time. Drop a new file after downloading the compressed version to process the next one. For batch work, consider a desktop tool like Ghostscript.
About this tool
PDF compression works by re-rendering each page at a lower resolution and encoding the result as a compressed JPEG image inside a new PDF. The trade-off is straightforward: lower DPI and quality settings produce a smaller file at the cost of some image sharpness.
This compressor uses pdf.js to render pages and jsPDF to assemble the output, all running in your browser. No server touches your data. The “Balanced” preset (120 DPI, medium JPEG quality) is a good default for most documents. For scanned documents and image-heavy reports, “Maximum compression” can cut file size by 50–80%.
Need to do more with your PDFs? Convert pages to images with the PDF to PNG converter, combine files with the PDF merger, or pull out specific pages with the PDF splitter.
Where your documents go
Nowhere. Compression runs entirely inside this browser tab — no file data is sent to a server, logged, or stored. Close the tab and everything is gone.