PDF Compressor
Reduce PDF file size online — lossless clean-up or strong image compression, batch files, 100% private (no upload).
How to Use the PDF Compressor
- Drop one or more PDFs (or click to browse). Batch compression is supported.
- Pick a level: Lossless (keeps selectable text), Balanced, Strong, Extreme, or Custom with your own DPI and quality sliders.
- Optionally enable Grayscale for extra savings on scanned documents.
- Click Compress and watch per-file progress.
- Download each file individually, or grab everything at once with Download all (ZIP).
What is the PDF Compressor?
A free, private, browser-based tool that reduces PDF file size. Lossless mode re-packs the PDF structure (object streams, stripped metadata) so text stays selectable. The image modes rebuild each page as an optimized JPEG at your chosen resolution — the proven way to shrink scanned documents and image-heavy PDFs dramatically. Powered by PDF.js and pdf-lib; nothing is ever uploaded to a server.
Common Use Cases
Why Choose Our PDF Compressor
- ✅ True batch mode — compress many PDFs and download a single ZIP
- ✅ Lossless option — keeps text selectable and searchable
- ✅ 4 presets + Custom — DPI and quality sliders for full control
- ✅ Grayscale mode — extra savings on scans
- ✅ Before/after sizes — see exact savings per file and in total
- ✅ 100% private — no upload, no server, no file-size limits
- ✅ Dark mode & fullscreen — comfortable on any screen
- ✅ Free forever — no sign-up, no watermarks
Frequently Asked Questions
How much smaller will my PDF get?
Scanned and image-heavy PDFs typically shrink 60–90% on Balanced or Strong. Text-only PDFs gain less from image modes; use Lossless there, which usually trims 5–30% depending on how the file was produced.
Will my text stay selectable?
In Lossless mode, yes — the PDF structure is repacked without touching content. The image modes (Balanced/Strong/Extreme/Custom) rebuild pages as pictures, so text becomes non-selectable; that trade-off is what enables the biggest savings.
Is there a file size or page limit?
No hard limit — processing happens on your device, so capacity depends on your browser's memory. Very large files (hundreds of pages) simply take longer.
Can I compress multiple PDFs at once?
Yes. Drop as many as you like; each shows its own before/after size, and Download all (ZIP) bundles every compressed file into one archive.
What DPI should I choose in Custom mode?
150 DPI looks crisp on screen and in normal printing. 120 DPI is a good email compromise. 96 DPI or lower suits archives where size matters most.
Why did Lossless barely reduce my file?
If the PDF was already efficiently built, there's little structural waste to remove. Switch to Balanced or Strong for real savings — or accept that the file is already optimal.
Are my files uploaded anywhere?
No. PDF.js renders and pdf-lib rebuilds your file entirely inside your browser. Nothing ever leaves your device — safe for contracts, IDs, and medical records.
Can I compress a password-protected PDF?
No — encrypted PDFs can't be processed in-browser. Unlock the file first in a desktop reader, then compress it here.