Does compression lose quality?

Recommended is visually lossless for most documents. Strong downsamples images harder, which shows on photographs and much less on scanned text.

Can I compress a scanned document?

Scans benefit most, because a scan is a stack of images rather than text. If you also want the text to be searchable afterwards, run OCR first, compressing does not create a text layer.

Compress PDF

No upload · runs in your browser

Drop a PDF to compressOne file at a time. We’ll estimate the savings instantlySelect files No upload · processed locally · auto-deleted

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.

FAQ

No. None of the three levels stamps anything onto the page.

It depends almost entirely on how much of the file is images. The size shown before you run it is a projection from the level you picked, roughly four-fifths of the original at Less, a bit over a third at Recommended, under a fifth at Strong, not a measurement of your particular document. The real figure appears after the run, and if it isn't good enough you can pick another level and go again without re-adding the file.

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Guides for this tool

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