Compress PDF Online Free – Reduce Scanned PDF File Size
Reduce scanned and image-heavy PDF file sizes locally in your browser. No upload, no signup — your files never leave your device. Best-effort target size for scanned PDFs; text and interactive PDF features are not preserved.
Drag & Drop your PDF files here
or click to browse from your device
Up to 10 PDFs · max 50 MB each · processed 100% in your browser
💡 Smart auto converts document pages to compressed pictures. A target is best effort, not guaranteed. This tool rebuilds pages as images: searchable text, links, forms and digital signatures are not retained. Use it for scanned documents and always keep the original.
Free Online PDF Compressor for Scanned Documents
Use this PDF compressor online to reduce the file size of scanned papers and image-heavy documents for sharing or uploading. Choose PDFs from your device, keep the smart default or enter a target size in KB or MB, and download the rebuilt PDF. Processing happens in your browser without sending the document to an upload service.
Important: this tool performs image-based PDF compression. It converts every page to a picture and combines those pictures into a new PDF. This works particularly well for scans, but it is not a lossless PDF optimizer. Text selection, search, links, digital signatures, interactive forms and accessibility structure are lost.
How to Reduce PDF File Size
Select a PDF
Add up to 10 PDF files (50MB each). The files are read locally in your browser.
Choose a target
Leave the target empty for automatic compression or enter a goal such as 500KB or 1MB.
Download and verify
Save the output. Check size, page order, readability and whether your receiving portal accepts it.
PDF to 100KB, 200KB, 500KB, 1MB or 2MB: What to Expect
Job applications, academic portals and email systems can specify different upload-size ceilings. The same target does not work for every file: a one-page scan and a 40-page photograph-heavy PDF contain very different amounts of information.
| Size goal | Practical guidance |
|---|---|
| 100KB | Very aggressive target; often only feasible for a short, simple scan. Text may become hard to read. |
| 200KB | Try for a short scan; verify fine print, stamps and photographs. |
| 500KB | Useful starting target for short image-based documents; result depends on page count. |
| 1MB | A more forgiving starting point for several scanned pages. |
| 2MB | Often easier to meet while retaining legible scanned text. |
Why scanned PDFs become large
A scanner can save each page as a high-resolution full-page picture. Re-encoding those pictures at a smaller size is often effective. By comparison, a digitally generated PDF with embedded text and vector graphics may already be compact and may become larger when rasterized.
PDF compression versus PDF optimization
True document-preserving optimization can remove unused objects or recompress embedded images while keeping text, bookmarks and forms. This browser tool uses rasterization instead. If preserving document features is essential, use a PDF optimizer designed for that job rather than this scan compressor.
Best Practices Before You Upload a Compressed PDF
Check every page
View the new PDF at 100% and 200% zoom to check small characters, stamps and photos.
Keep the original
Save your untouched document as a backup, especially if it is important.
Use the right type
For signed, fillable or searchable PDFs, use non-rasterizing optimization.
If the resulting file still exceeds an upload limit, consider reducing the number of pages where allowed, scanning at a lower resolution or rescanning from the original. Do not rely on unreadable files for official submissions.
Frequently Asked Questions
How can I compress a PDF online for free?
Add a PDF to the tool, leave the optional target blank for automatic processing or enter a desired size, then compress and download. It runs in your browser.
Can I compress a PDF to 100KB, 200KB or 500KB?
You can enter a target such as 100KB, 200KB or 500KB. The tool makes a best-effort attempt, but very small targets may not be achievable; always verify the final file size.
Will the compressed PDF keep selectable text and links?
Not with this tool. It renders pages into images and builds a new image-based PDF. Selectable text, original hyperlinks, forms, annotations and accessibility tags are not retained.
Can I compress a digitally signed PDF?
Do not use this tool for a digitally signed PDF if the signature must remain valid. Rebuilding the document invalidates the original digital signature and can remove certificate information.
Is this suitable for scanned documents?
Yes, scanned or image-heavy PDFs are the best fit. Even then, review readability, page count and actual downloaded size before submitting.
Can I compress a PDF without quality loss?
This tool uses image re-encoding, so it does not provide lossless optimization. Choose a less aggressive target or use a PDF optimizer that preserves document objects when you must retain text and vector content.
Why can the compressed PDF be larger than the original?
A text-only or already optimized PDF may be very small. Turning its pages into images may increase file size rather than reduce it. This tool keeps the original when the generated PDF is larger in automatic mode.
Is the PDF uploaded or stored?
No. The tool renders the document locally using JavaScript. Normal site assets, analytics or ads are separate from the document-processing logic.
Does it support password-protected PDFs?
Encrypted files may require a password. This version does not provide a password entry field, so open or unlock an authorized copy first and then process it.
Can I convert PDF pages to JPG or PNG?
Yes. The output selector offers JPG or PNG export of the first PDF page only. For a multi-page PDF, choose PDF output to retain all pages as raster images.
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