PDF Compressor - Free Desktop App
Reduce PDF file size by up to 90% without visible quality loss. No uploads, works offline, unlimited compressions.
Compress Your PDFs
Reduce file size by up to 90%
Your PDF will be compressed using smart algorithms that reduce file size while maintaining readability. Perfect for email attachments and web uploads.
Note: All processing happens locally on your computer. Your files never leave your device.
PDF Compressor Comparison: Diwadi vs iLovePDF vs Smallpdf vs Adobe
See how Diwadi stacks up against the most popular PDF compression tools
| Feature | iLovePDF | Smallpdf | Adobe Acrobat | PDF24 | Diwadi |
|---|---|---|---|---|---|
| File Upload Required | Yes, cloud upload | Yes, cloud upload | Yes, cloud upload | Yes, cloud upload | No upload needed |
| File Size Limit | 200 MB (free) | 5 GB (paid) | 2 GB | 100 MB | Unlimited |
| Compression Levels | 3 levels | 2 levels | 3 levels | 3 levels | 3 levels + fine-tuning |
| Privacy & Security | Files on their servers | ISO 27001 certified | Files on Adobe servers | Files on their servers | 100% local processing |
| Offline Support | No | No | Desktop app only | Desktop app available | Fully offline |
| Batch Processing | Yes (limited free) | Paid only | Yes | Yes | Unlimited |
| Speed | Depends on upload | Depends on upload | Depends on upload | Depends on upload | Instant (local) |
| Cost | $4/mo (Premium) | $9/mo (Pro) | $12.99/mo | Free (desktop) | Free |
How It Works
Download & Install
Takes just 30 seconds. No account, no credit card required.
Browse & Select Your Large PDF Files
Navigate your files like a regular file browser. Batch processing supported.
Get Compressed PDFs (up to 90% smaller) (Instant)
Processing happens locally on your computer. No upload wait.
Choose Your Compression Level
Balance between file size and visual quality based on your needs
Maximum Compression
Up to 90% smaller
Aggressive compression for smallest possible file size. Some quality reduction in images.
Best for: Email attachments, web uploads, forms
Balanced
Up to 70% smaller
Smart compression that maintains good visual quality while significantly reducing size.
Best for: Most documents, presentations, reports
Quality Priority
Up to 40% smaller
Minimal compression that preserves image quality. Text and graphics remain crisp.
Best for: Portfolios, photos, print documents
Compress PDF to Target Size
Need to meet a specific file size requirement? Here are the most common target sizes and when you need them.
100 KB
Web Forms & PortalsGovernment forms, job applications, and university portals often enforce a strict 100KB limit. Use Maximum compression and reduce image-heavy pages.
Use Maximum preset. Remove embedded images if possible.
200 KB
Online ApplicationsMany online submission systems and HR platforms require documents under 200KB. Ideal for resumes, cover letters, and single-page forms.
Use Balanced preset for clean text documents.
500 KB
Document SharingA common threshold for internal document management systems and shared drives. Works well for multi-page reports with moderate graphics.
Use Balanced preset. Most 5-10 page reports fit easily.
1 MB
Email & MessagingPerfect for email attachments and messaging apps. A 1MB PDF loads quickly on mobile devices and passes through most email filters.
Use Balanced preset for documents with images.
2 MB
Presentations & BrochuresSuitable for image-rich presentations and marketing materials. Maintains good visual quality while keeping files manageable for sharing.
Use Quality Priority preset for visual documents.
5 MB
Large Reports & CatalogsWorks for lengthy documents with charts, tables, and photos. Most email providers accept 5MB attachments without issues.
Use Quality Priority preset to preserve all details.
Diwadi compresses PDFs locally with no upload required. Unlike online tools with file size limits, you can compress PDFs of any size instantly on your machine.
How PDF Compression Works
Understanding what happens when you compress a PDF helps you choose the right settings for your documents.
PDF compression reduces file size by applying several techniques to the different elements inside your document. Here is what happens behind the scenes when Diwadi compresses your PDFs.
Image Downsampling
Embedded images are the biggest contributor to PDF file size. Compression reduces image resolution and applies lossy or lossless encoding depending on your chosen quality level. A 300 DPI photo might be resampled to 150 DPI, cutting its data in half while remaining sharp on screen.
Metadata Removal
PDFs often contain hidden metadata: editing history, thumbnail previews, embedded fonts that are no longer referenced, and XML data from the creating application. Stripping this unused data can reduce file size by 5-15% with zero visual impact.
Font Subsetting & Optimization
If a PDF embeds a full font file but only uses 50 characters, font subsetting removes the unused glyphs. This is especially effective for documents using multiple decorative or large font families.
Content Stream Compression
PDF content streams (text, vector graphics, page descriptions) are recompressed using efficient algorithms like Flate/Deflate. Redundant objects are merged, and the internal structure is optimized to eliminate duplicate data across pages.
Diwadi applies all of these techniques locally on your machine. Your files are never uploaded to any server, so confidential documents stay private throughout the entire compression process.
Why Compress PDFs?
Make your documents easier to share and store
Email Attachments
Stay under email size limits (usually 10-25MB)
Web Uploads
Faster uploads to portals and forms
Storage Space
Reduce cloud and local storage usage
Website Downloads
Faster downloads for your website visitors
Why Choose Diwadi Desktop?
Privacy First
Files never leave your computer. No cloud upload, no data collection, 100% local.
Lightning Fast
Process files 10x faster than online tools. No upload wait, no download wait.
No Limits
Convert unlimited files of any size. Batch process thousands in one click.
AI-Powered
Smart formatting detection, auto-cleanup, better accuracy.
Works Offline
No internet required. Perfect for flights, secure environments.
Free to Use
No trial limits, no watermarks, no credit card required.
Frequently Asked Questions
Is the PDF compressor really free?
Yes, completely free with no limits. Compress unlimited PDF files of any size, as many times as you want. No watermarks, no signup, no credit card required.
Will compression reduce my PDF quality?
It depends on the compression level you choose. 'Quality Priority' preserves visual quality with moderate size reduction. 'Balanced' (recommended) reduces size significantly with minimal visible quality loss. 'Maximum' achieves smallest size with some quality trade-off.
Do my PDFs get uploaded to a server?
Never. All PDF compression happens locally on your computer. Your files never leave your device - unlike iLovePDF, SmallPDF, or other online tools.
How much can I reduce my PDF size?
Depending on your PDF content and compression settings, you can reduce file size by 40-90%. PDFs with many images compress more; text-heavy PDFs compress less.
Will text remain searchable after compression?
Yes, text in your PDF remains fully searchable and selectable after compression. Only images are compressed, not the text content.
Can I compress multiple PDFs at once?
Yes! Batch compress unlimited PDFs in a single operation. Select all files, choose your compression level, and compress them all at once.
Does it work offline?
Yes, Diwadi works 100% offline after installation. No internet required for PDF compression.
What platforms are supported?
Mac (Apple Silicon and Intel), Windows (10, 11). Download the version for your operating system.