Compress PDF
Reduce the file size of a PDF for free so it's small enough to email or upload — entirely in your browser. Your file is never uploaded to a server.
How to compress a PDF
- Open the Compress tool and add your PDF — drag and drop it, or click “Choose files.”
- Pick a level. Choose Light (best quality), Recommended (a good balance), or Maximum (smallest file).
- Compress & download. The smaller PDF is generated on your device and saved to your Downloads folder.
Shrink PDFs without uploading them
The document tools process file contents in your browser rather than uploading them for processing. Working files remain in page memory; downloads remain wherever you save them. Informational pages may load ads or analytics; the document-opening page excludes them. Read the privacy policy for details.
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Compress PDF — FAQ
Is compressing PDFs on LambiPdf free?
Yes — it's completely free, with no sign-up and no watermark.
Are my files uploaded when I compress?
No. Compression happens entirely in your browser; file contents are not uploaded for processing.
How much smaller will my PDF get?
It depends on the file and the level you choose. Scanned or image-heavy PDFs shrink the most; the Maximum level gives the smallest file.
Will the text still be selectable after compressing?
Compression re-renders pages as images, so text becomes part of the page image. If you need selectable text afterwards, use the OCR tool.