PDF Compressor
Reduce PDF file size by re-encoding images — all in your browser.
Drop PDFs here
PDF files · one or many
Click to browse, or paste files and links (Ctrl/⌘ + V)
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About PDF Compressor
Reduce PDF file size by re-encoding embedded JPEG and PNG images at lower quality, optionally scaling them down and stripping metadata. Uses pdf-lib running entirely in the browser — your file is never uploaded to a server. Works best on image-heavy PDFs; text-only PDFs will see little change.
Is my PDF uploaded anywhere?
No. Compression happens entirely in your browser using pdf-lib. Your file never leaves your device.
How does compression work?
The tool re-encodes embedded JPEG and PNG images at lower quality and smaller dimensions, strips metadata (for Screen/eBook/Printer levels), and reserialises the PDF using object streams.
Why is the output sometimes similar in size?
Text-only PDFs have very little image data to compress. Savings are largest on PDFs with many embedded photographs.
Is encryption supported?
Encrypted PDFs are loaded with ignoreEncryption — content is processed but the output is unencrypted.
Related: Image Compressor · File Diff
Keywords: PDF compressor, compress PDF browser, reduce PDF size, PDF optimiser, no upload PDF tool