Free PDF Compressor - Reduce PDF File Size Online
Shrink large PDFs for email, storage, or sharing. Choose compression level (Moderate / High / Maximum), enable Grayscale for extra reduction, strip metadata, and get an instant before/after size comparison — all in your browser, nothing uploaded.
Reduce PDF file size for email, storage, or sharing. Choose your compression level, optionally convert to grayscale for extra reduction, then compress — all in your browser, nothing uploaded.
Drop a PDF file here
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PDF only · Single file · Any file size
Compression Level
Compressing…
What is Compress PDF?
Large PDF files cause headaches: email attachments get rejected, upload forms impose size limits, and slow downloads frustrate recipients. Our free PDF Compressor reduces file sizes dramatically while giving you full control over the quality-size trade-off.
Choose from three compression levels: Moderate (~30–50% reduction, best visual quality for printing and presenting), High (~50–70% reduction, ideal for email and portal uploads), or Maximum (~70–85% reduction, for archival where file size is the priority).
Enable Grayscale mode to convert all content to black and white for additional size reduction — particularly effective for text-heavy documents and scanned PDFs. Toggle Strip Metadata to remove author, title, and software information from the output, reducing file size further and protecting your privacy.
A before-and-after file size comparison is shown immediately so you always know exactly how much space was saved. You can re-compress the same file with different settings instantly — no need to re-upload. Everything runs locally in your browser, so your confidential documents, financial statements, or medical records are never sent to any server.
Powerful Features
Everything you need in one amazing tool
Three Compression Levels
Choose Moderate (best quality), High (balanced), or Maximum (smallest file) to match your exact quality-size requirement.
Before/After Size Comparison
Instantly see original vs compressed file size and the exact percentage reduction after every compression.
Grayscale Mode
Convert all content to black and white for extra size reduction — especially effective for text-heavy documents and scans.
Strip Metadata
Remove author, title, and software information from the output to reduce file size and protect document privacy.
Private Processing
Files never leave your device. All compression runs locally in your browser — zero server uploads.
Compress Again Without Re-uploading
Adjust settings and re-compress the same file instantly. No need to upload again to try different levels.
How It Works
Get started in 4 easy steps
Upload Your PDF
Drop or select the PDF you want to compress. File size is shown immediately.
Configure Settings
Pick a compression level (Moderate / High / Maximum), optionally enable Grayscale for extra reduction, and toggle Metadata Stripping.
Compress
Click Compress PDF. The browser optimizes the file and shows the size reduction.
Download or Compress Again
See the before/after size comparison, download your file, or click Compress Again to try different settings — no re-upload needed.
Why Choose Our Compress PDF?
Stand out from the competition
Confidential Files Safe
Financial reports, legal docs, and medical PDFs never leave your device.
Transparent Results
Clear before/after comparison so you know exactly what compression delivered.
Quality Control
Three compression levels let you choose the right quality-size balance for your use case.
No Server Queue
Instant results with no waiting. Compression finishes in your browser immediately.
Size Comparison Display
Get an instant before/after comparison after every compression — original size, compressed size, and % reduction, all clearly displayed.
Free, Zero Limits
No file count limits, no watermarks, no sign-up needed. 100% free and completely private.
Perfect For
See how others are using this tool
Email Attachments
Reduce PDF size to fit within email attachment limits (25 MB for Gmail).
Cloud Storage
Save cloud storage space by compressing large archives of PDF documents.
Web Publishing
Compress PDFs for fast web downloads. Smaller files mean faster load times and a better experience for your readers.
Mobile Sharing
Reduce size before sharing via WhatsApp, Telegram, or other mobile apps that enforce attachment limits.
Portal & Form Uploads
Meet strict file size limits on government portals, job boards, CRM systems, and HR platforms.
Scanned Document Archival
Use Grayscale + Maximum compression to shrink scanned image PDFs for long-term storage without wasting space.
Frequently Asked Questions
Everything you need to know about Compress PDF
Typical reductions range from 30–85% depending on the compression level chosen and the content of the PDF. Moderate achieves ~30–50%, High ~50–70%, and Maximum ~70–85%. Enabling Grayscale mode can push reductions even further.
Moderate renders pages at the highest resolution and JPEG quality — ideal for documents you need to print or share in meetings. High is balanced and perfect for email. Maximum delivers the smallest possible file, best for archival or portals with strict size limits.
It converts all page content to black and white before compression. This is particularly effective for text-heavy documents, spreadsheets, and scanned PDFs where colour information is not needed, achieving significantly smaller files.
No. All compression runs entirely in your browser using JavaScript. Your file never leaves your device, making it safe for confidential, legal, or medical documents.
Use Moderate for documents you will print or display at full size. Use High for email attachments and online uploads. Use Maximum when file size must be minimised, such as for archival storage or government portals with strict upload limits.
Yes. After each compression you see the results and can click 'Compress Again' to adjust the level, toggle Grayscale, or change any option and re-compress instantly — no need to upload the file again.
No. The output is a standard PDF 1.7 file that opens in all PDF viewers including Adobe Acrobat, Mac Preview, Google Chrome, and mobile apps.
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