Compress PDF Files Online
Reduce file size while keeping the best quality possible. Free, secure, and works on any device — no signup required.
Most PDFs are bigger than they need to be. A 40 MB scanned contract that won't fit through your email gateway is usually 38 MB of high-resolution images that look identical at 1/4 the size. PDFWix's compressor downsamples those images, subsets embedded fonts, and rewrites the file with the same visible quality at 50–80% of the original size. The Recommended preset is the right call almost every time; High squeezes harder when you really need to fit under a strict cap; Low keeps print-grade fidelity. The whole job runs in your browser — your file never reaches our server.
or drop PDFs here
Stream-based optimization preserves quality. For deeper image compression, use server-side processing (coming soon).
Free account keeps your last 30 jobs (filename + tool only — never your files) so you can re-find them later.
🔒 HTTPS · Browser-side processing · 100% free
How to Compress PDF
- 1
Upload your file
Click "Select PDF files" or drag and drop the document into the upload box. Multiple files are supported where it makes sense.
- 2
Configure options
Pick the settings on the right — the defaults work for 90% of jobs, so most users can skip straight to the next step.
- 3
Click "Compress PDF"
PDFWix processes the file instantly in your browser. No upload progress bar, no waiting.
- 4
Download the result
Save the new file to your device. The original file is never modified.
Tips for compressing PDFs
Recommended is the default for a reason
It's the preset we'd pick for ourselves: ~70% smaller, no visible loss on screen. Only switch to High when you're up against a hard email size cap.
Already-compressed PDFs barely shrink
If a PDF was exported from Word or InDesign with image compression, you may only see 10–20% reduction. The big wins are on scanned documents and screenshots.
Compress after [merging](/merge-pdf), not before
Compression slightly degrades image quality each pass. Do it once, at the end of your workflow.
Need OCR text to stay searchable?
Compression preserves the text layer added by OCR PDF. Your search and copy/paste still work.
For print, use Low
If the PDF goes to a commercial printer, the High preset can introduce visible JPEG artifacts at 11×17. Low keeps print-grade fidelity.
Why use PDFWix to compress PDFs?
- Completely free. compress as many PDFs as you need without paying a cent or hitting a paywall.
- No signup required. Skip account creation. Just upload, compress, and download.
- Works on any device. Whether you're on Windows, Mac, Linux, iPhone, or Android — PDFWix runs entirely in your browser.
- Privacy first. Your files are encrypted in transit and automatically deleted from our servers within an hour.
- Lightning fast. Most compress jobs finish in under 10 seconds, even for large files.
- Preserves quality. Text, images, and formatting stay exactly as they were in the original PDF.
Need to shrink a PDF below an email limit? Compress first, then merge any extras into a single file. Password-protected PDFs need to be unlocked before compression.
Common uses for compressing PDFs
- Compress PDF for monthly reports and expense filings
- Compress PDF for academic papers and references
- Compress PDF for contracts and signature workflows
- Compress PDF for ebooks and training manuals
- Compress PDF for tax documents and accountant submissions
Frequently asked questions
How much can compression reduce file size?
Most PDFs shrink by 50–80%. Image-heavy PDFs compress most; text-only PDFs already use little space and gain less.
Will compressed PDFs lose image quality?
On the Recommended preset there's no visible loss for screen reading. The High preset trades minor visible quality for the smallest file. Use Low if the PDF will be printed at large sizes.
Is my file uploaded?
Compression runs entirely in your browser — your file never leaves the device. We literally cannot see it.
What's the maximum file size?
There's no hard cap. Browser-side processing scales with your device's RAM. We've tested up to 500 MB.
Does it work on password-protected PDFs?
Unlock the PDF first using our free Unlock PDF tool, then run compression.
More PDF tools
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Combine PDFs in the order you want with the easiest PDF merger.
Split PDF
Separate one page or a whole set for easy conversion into independent PDF files.
PDF to JPG
Convert each PDF page into a JPG, or extract images from PDFs.
Repair PDF
Repair a damaged PDF and recover data from corrupt files.