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Optimize PDF

Compress PDF

Shrink PDF file size while keeping it crisp. Pick a compression level, preview the savings, and download, all processed privately in your browser.

Drop a PDF to compress
One file at a time. We’ll estimate the savings instantly
No upload · processed locally · auto-deleted
A · Keep going

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B · How it works

How to compress a PDF without losing quality

FernPDF’s compressor analyzes your PDF and optimizes images, fonts, and structure to cut file size while preserving sharpness. Pick a level, preview the savings, and download.

Because everything runs locally in your browser, you can compress sensitive documents (tax records, medical scans, signed contracts) without ever sending them to a third-party server.

Smaller PDFs are easier to email, faster to load, and cheaper to store. “Recommended” is visually lossless for most files; “Strong” goes further when size matters most.

C · FAQ

It depends on the content. Image-heavy PDFs often shrink 60–90%; text-only files less. The estimate updates live as you pick a level, and you only download if you’re happy with the result.

“Recommended” is visually lossless for most documents. “Strong” downsamples images more aggressively for the smallest size. You preview the trade-off before downloading.

No. Compression runs entirely in your browser. Your PDF is read, optimized, and re-saved on your device, and nothing is sent to a server.

Yes. Scanned PDFs (which are really images) benefit most from compression. Pair it with OCR first if you also want the text to be searchable.