PDF Compressor

Reduce PDF file size with adaptive DPI scaling. Works offline.

📄 Drop PDF here or click to browse PDF · up to 200 MB

What is this PDF compressor?

This free PDF compressor gives you four modes — lossless (keeps text selectable), balanced, maximum and custom — plus a target-size option that auto-tunes quality to fit a limit like 5 MB, all running entirely in your browser so your documents are never uploaded.

How can I make a PDF smaller without uploading it online?

Drop your PDF in, pick Balanced or Maximum compression, and click Compress. The tool re-encodes images at a lower DPI in your browser and lets you download a smaller file — with no upload.

Key features

Four compression modes
Lossless keeps text sharp and selectable; Balanced and Maximum rebuild pages as images; Custom lets you dial in DPI and quality.
Target a file size
Give it a budget such as 5 MB for email and it auto-tunes resolution and quality to fit under the limit.
Grayscale & live preview
Optionally convert pages to grayscale for big savings on scans, and preview the first compressed page before downloading.
Private & offline
Every byte is processed on your device with pdf-lib and PDF.js — contracts, invoices and reports are never uploaded.

How to use it

Drop your PDF in, then pick a mode: Lossless to shrink without touching text, Balanced or Maximum to rebuild pages as compressed images, Custom for manual DPI and quality, or Target size to fit under a limit like 5 MB. Watch the page-by-page progress, check the before/after sizes and preview, then download — the original never leaves your computer.

Frequently asked questions

Is my PDF uploaded to a server?

No. Compression happens entirely in your browser, so sensitive documents are never transmitted or stored anywhere.

Why didn't a text-only PDF shrink much?

Compression mainly re-encodes images. A PDF that is mostly text is already small, so there is little to remove.

Will compression ruin the quality?

Balanced mode preserves readable text and images; Maximum trades some image sharpness for the smallest file.

Tooljar builds this on the open-source pdf-lib and PDF.js libraries used across the industry, applying conservative DPI targets so compressed files stay legible for email, printing and archiving.