Compress PDF
Free online PDF compressor that reduces file size directly in your browser. No uploads, no sign-up — your documents stay private.
Works best on image-heavy PDFs. Text-only or already optimized PDFs may see limited reduction.
Choose your Files...
Compression Settings
Uncheck to remove metadata (author, title, etc.) from PDF
Why Compress PDF Files?
PDF files grow large fast — especially when they contain scanned pages, high-resolution images, or embedded graphics. A single report with charts can easily hit 20 to 50 MB. That makes it impossible to email, slow to upload to portals, and expensive to store in the cloud.
Most email providers cap attachments at 10 to 25 MB. College submission portals, government forms, and job application sites often have even stricter limits. When your PDF is too large, you need a way to reduce PDF size quickly without destroying the content.
Email Limits
Most providers reject attachments over 10-25 MB. Compress PDF to fit any inbox.
Upload Portals
College, government, and job sites have strict file size caps. Reduce PDF size to meet them.
Storage Costs
Smaller PDFs save cloud storage space and bandwidth for teams handling thousands of documents.
How Our PDF Compressor Actually Works
Most online tools upload your PDF to a remote server for processing. We do things differently. Our PDF compressor runs entirely inside your browser — your files never leave your device.
Here is what happens when you compress a PDF: First, PDF.js (Mozilla's open-source PDF renderer) renders each page to a canvas at your chosen DPI. Then, each canvas is compressed to an optimized JPEG image at the quality level you selected. Finally, pdf-lib assembles those compressed images into a brand new, smaller PDF file. The entire pipeline runs in JavaScript — no server, no upload, no waiting.
Compression Presets
Insane (20 DPI) • Minimum (40 DPI) • Normal (72 DPI) • Ebook (96 DPI) • Printer (150 DPI) • Prepress (200 DPI)
Lower DPI means smaller files. "Normal" is ideal for screen viewing. "Printer" and "Prepress" preserve detail for physical printing.
What Makes This PDF Reducer Different?
There are dozens of PDF compression tools online. Most of them upload your documents to a server, slap a watermark on free users, or limit you to one file per day. Here is what we do differently.
100% Private — Nothing Leaves Your Device
Your PDF is compressed using PDF.js and the HTML5 Canvas API directly inside your browser. No file is ever uploaded to any server. We cannot see, access, or store your documents. Once you close the tab, all data is gone from memory. No cookies track your files, no registration is needed.
Six Compression Presets for Every Use Case
Need the smallest possible file? Use "Insane" at 20 DPI. Need to print the result? Use "Printer" at 150 DPI. The "Normal" preset at 72 DPI is perfect for screen viewing and email. Each preset controls both the render resolution and JPEG quality — giving you precise control over the size-quality tradeoff.
Fast — No Waiting for Server Processing
Since compression happens on your device, there is no upload time, no queue, and no waiting for a remote server to finish. A 10 MB PDF typically compresses in 2 to 5 seconds depending on page count. Multi-page documents are processed in parallel for maximum speed.
Free, Unlimited, No Watermarks
Compress as many PDFs as you want. There is no daily limit, no file count restriction, and no watermark added to your output. The tool works the same whether you compress one file or fifty. No account needed, no credit card, no upsell.
How to Compress a PDF in Three Steps
No technical knowledge needed. Upload, pick a preset, and download your smaller PDF.
Step 1: Upload Your PDF
Drag and drop your PDF file into the upload area, or click to select from your device. You can also paste a PDF from your clipboard (Ctrl+V or ⌘V). Each file can be up to 50 MB. Upload multiple PDFs to compress them all in one session.
Step 2: Choose Compression Settings
Pick between Quick Compression (High or Low quality) or PDF Quality Presets for more control. Here is what each preset does:
Step 3: Download Your Compressed PDF
Click "Compress PDF" and wait a few seconds. The result shows you the original size, compressed size, and exact percentage saved. Download your smaller PDF instantly — no email required, no waiting for a link. The compressed file is ready the moment processing finishes.
PDF Resize Guide: Choose the Right Preset
Not sure which setting to use? Here is a simple guide based on how you plan to use the compressed PDF.
| Preset | Best For | Typical Reduction | Output Quality |
|---|---|---|---|
| Insane (20 DPI) | Quick previews, file size is everything | 85-95% | Low — text may be hard to read |
| Minimum (40 DPI) | Thumbnails, rough drafts | 75-90% | Basic readability |
| Normal (72 DPI) | Email, screen viewing, web sharing | 60-80% | Good — clear on screens |
| Ebook (96 DPI) | Tablets, e-readers, presentations | 50-70% | Great — sharp on high-DPI screens |
| Printer (150 DPI) | Office printing, handouts | 30-50% | High — suitable for printing |
| Prepress (200 DPI) | Professional printing, archiving | 20-40% | Excellent — near-original detail |
Tip: For most people, "Normal" (72 DPI) gives the best balance. It produces files small enough to email while keeping text and images perfectly readable on any screen. Use "Printer" only if you plan to physically print the document.
Built for Everyone Who Works with PDFs
Whether you are submitting an assignment, emailing a contract, or archiving old documents, this PDF compressor fits your workflow.
Students
Compress scanned assignments, thesis PDFs, and research papers to meet college portal upload limits. Most educational platforms cap submissions at 5 to 10 MB — our "Normal" preset handles that easily.
Professionals
Reduce PDF size for contracts, reports, and presentations before emailing to clients. Fit large slide decks under the 25 MB Gmail limit without opening Adobe Acrobat or paying for a subscription tool.
Freelancers
Shrink portfolio PDFs, design proofs, and invoices for faster delivery. When clients need a quick preview, use a lower preset to send a compact PDF in seconds — then share the full-quality version later.
Everyday Users
Compress scanned documents, tax forms, and receipts for cloud storage. A 30 MB scanned document can drop to 3 MB at "Normal" quality — saving space on Google Drive, Dropbox, or iCloud without losing readability.
Testimonials
What our users say about this PDF compressor
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Frequently Asked Questions
Everything you need to know about compressing PDF files with this tool