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FileConvertIt
PDF Tool

Compress PDF Free

Reduce PDF file size with lossless Basic mode or aggressive Strong image compression. No uploads — everything runs in your browser.

🔒 Private — no uploads ⚡ Instant results 📉 Up to 80% smaller

How to Compress a PDF Online

Drop your PDF onto the tool above. Choose Basic mode to compress without any quality loss (ideal for text-heavy PDFs), or Strong mode to aggressively shrink image-heavy or scanned PDFs by re-encoding pages as JPEG at reduced quality. Click Compress PDF and download your smaller file instantly.

Basic vs Strong Compression

Basic uses lossless stream deflation via pdf-lib. It removes redundant cross-reference tables and compresses internal streams. The result is fully lossless — every pixel and font remains identical. Typical reduction: 10–30%.

Strong re-renders each page using a PDF rendering engine and re-encodes them as JPEG at 72% quality. This is especially effective for scanned documents or image-heavy PDFs. Typical reduction: 40–80%. Vector text on image backgrounds will look slightly softer but remain readable.

Why FileConvertIt is Different

Unlike Smallpdf, iLovePDF, or Adobe Acrobat Online, FileConvertIt compresses your PDF entirely inside your browser. Your document is never uploaded to any server — there is zero risk of a data breach, no account required, and no file size limit beyond your available browser memory.

Frequently Asked Questions

Which compression mode should I choose?
Use Basic for text-heavy PDFs (contracts, reports) where you cannot afford any quality loss. Use Strong for scanned documents, photo books, or any PDF where images dominate — you'll get a much smaller file with only a slight reduction in image sharpness.
How much smaller will my PDF get?
Basic typically achieves 10–30% reduction for PDFs that were not previously optimised. Strong mode typically achieves 40–80% reduction on image-heavy files. Results vary: a PDF that is already heavily compressed may see little change.
Will Strong mode affect text legibility?
Strong mode re-renders pages as JPEG images at 108 DPI and 72% JPEG quality. Text remains fully readable in most cases, but if your PDF contains tiny 6pt footnotes you may notice very slight blur. For text-critical documents, use Basic mode.
Is my PDF uploaded to your servers?
No. All compression happens inside your browser using WebAssembly. Your file never leaves your device. FileConvertIt has no server-side PDF processing — there is nothing to breach, log, or store.