Reduce PDF File Size
Upload your PDF and choose a compression level to reduce the file size. Lossless keeps everything identical; lower quality modes shrink the file more aggressively by re-rendering pages as images.
Drop a PDF here or click to browse
How it works
If you pick Lossless, pdf-lib rewrites the document using object streams, which trims overhead like duplicate fonts and verbose dictionaries while preserving text, images, bookmarks, and form fields exactly. The High, Medium, and Low modes use pdfjs-dist to render every page onto a Canvas, then export each page as a JPEG that pdf-lib stitches into a smaller replacement PDF. Both strategies finish in seconds for typical documents.
Processing runs in your browser
Whether you pick lossless or an image-based quality mode, the entire reduction happens inside your browser memory. The original file is read locally, the smaller replacement is written locally, and the only data leaving the tab is the download you trigger yourself. You can check this yourselfin your browser's DevTools Network tab.
Related operations
To stitch multiple PDFs into one before compressing, try merge PDF. For pulling out a subset of pages, use split PDF. To extract pages as standalone images, see PDF to image.
Frequently asked questions
- Why is my PDF file so large?
- Large PDFs usually contain uncompressed images, redundant objects, or embedded fonts with unused characters. Lossless compression removes this overhead. Image modes go further by replacing page content with compressed JPEG images.
- What is the difference between lossless and lossy compression?
- Lossless (object streams) makes the file smaller with no change to content. Lossy (High, Medium, Low) re-renders each page as a JPEG, smaller file but text becomes non-selectable and some visual quality is lost.
- Can I compress a password-protected PDF?
- Encrypted PDFs cannot be loaded or processed by this tool. Remove the password first using your PDF viewer, then compress.
- Does compression affect hyperlinks or bookmarks?
- Lossless compression preserves hyperlinks, bookmarks, and form fields. Image-based modes convert pages to images, which removes interactive elements.
- Is this tool free?
- Yes, completely free. No account, no sign-up, and all processing runs in your browser.