Compress PDF online

Smaller PDF files, same PDF format—server-side processing.

Drag & drop files here or browse. Max file size 100 MB for your account. Sign up or view pricing.

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Compression results

How your files are processed

Files are uploaded and processed on our servers, then made available for download.

What this tool does

PDF files smuggle weight inside embedded photos, duplicate fonts, or verbose Office XML. Compressing PDF in place keeps signatures, comments, and editor compatibility intact while shrinking upload size.

Pick gentler presets when fine lines must survive print.

PDF output remains PDF — Structure and page semantics stay PDF; optimization targets embedded images, font subsets, and object streams.
Image downsampling — Oversized raster figures drive megabytes; lowering DPI for screen review shrinks the file before layout vectors change.
Object streams — Repacking object compression reduces container overhead without altering visible text vectors.

How to compress PDF files?

Choose file — select a PDF file that matches this compressor (allowed extensions apply).
Adjust options — set quality, level, or advanced options if shown, then compress.
Download — grab the smaller file from your job page when processing completes.

Why compress PDF files?

Tune presets for your audience: screen viewing tolerates more downsampling than ink-on-paper proofs. HTML and TXT paths focus on whitespace hygiene; PDF and Office paths target redundant objects without changing the extension.

Common uses for PDF compression

Submit grant PDFs under municipal upload caps without splitting the packet.
Email PDF contracts when the mail gateway blocks oversized attachments.
Upload PDF Board packs to a portal that enforces a maximum megabyte per file.
Shrink PDF slide decks before webinar attendees download them on cellular.
Reduce PDF discovery bundles before transferring them across a metered VPN.
Prepare PDF print proofs that still stay under a printer’s upload ceiling.

Will compressing PDF (PDF) affect quality?

PDF optimization removes redundant objects and downsamples giant raster plates—vector outlines usually survive.

Aggressive downsampling softens fine lines and small type in scans; proof zoomed pages when contracts depend on legibility.

How PDF document compression works

Hidden bulk

Authors paste 300 DPI screenshots into slides, embed full-size photos in PDFs, or ship HTML with verbose whitespace.

What optimization targets

PDF compression rebuilds structure, down-samples oversized images inside pages, and applies object streams—screen preset favors smallest bytes, printer preset keeps sharper raster text.

Legal or print PDFs may need lossless image handling—pick a gentler preset when fine hairlines must survive zoomed review.

Troubleshooting

Already-optimized documents may not shrink much: some PDF files were already optimized elsewhere.
Embedded images dominate size: big photos inside PDFs often determine the final size.
Quality trade-offs can appear: downsampling images can reduce readability if pushed too far.
Very large documents take longer to process.

PDF compression FAQ

Subset embedding may drop unused glyphs but keeps on-page characters. Re-export from the authoring app if a rare glyph disappears.

Text-only pages or already compressed images leave little room. Gains usually come from downsampling oversized embedded rasters.

Yes when pages are full-color high-DPI scans. Downsampling for screen review often saves more than structural tweaks alone.

Well-behaved optimization preserves interactive fields, but always verify critical PDFs after processing.