Compress PDF

What is Compress PDF?

Compress PDF is an online tool that reduces PDF file size using Ghostscript, a powerful and widely used PDF processing engine. You can upload a local PDF from your device or provide a URL to fetch a PDF from the web. Four compression levels are available: screen (maximum compression, smallest file, lowest quality, best for on-screen viewing only), ebook (recommended balance of size and quality for most uses), printer (high quality suitable for printing), and prepress (minimal compression, best quality for archiving or pre-press workflows). The tool displays original and compressed file sizes, plus the percentage saved, so you can see exactly how much space you gain. Processing runs on the server; you download the compressed file when done. Large PDFs are common: high-resolution scans, embedded images, or documents with many pages. Sending them by email or uploading to forms often hits size limits. Compressing reduces file size for easier sharing, storage, and faster uploads and downloads.

Ghostscript uses PDFSETTINGS to control compression. Screen typically reduces images to 72 DPI and applies aggressive compression. Ebook uses about 150 DPI and provides a good balance. Printer keeps higher resolution for print quality. Prepress minimizes changes for archiving or professional printing. Text and vector content are also optimized. The exact savings depend on the source: image-heavy PDFs (scans, photos, screenshots) compress much more than text-only documents. A 10 MB scan might compress to 1 MB with ebook; a 1 MB text PDF might only reach 800 KB. Start with ebook for most documents. Use screen only when quality is unimportant and you need the smallest possible file. Use printer or prepress when you need to print or archive at high quality. Always check the result before discarding the original; ensure text remains readable and images are acceptable for your use.

Compression can be lossy or lossless. Screen and ebook use lossy compression: image resolution is reduced, and some detail may be lost. For documents that will only be viewed on screen or shared digitally, this is usually acceptable. Printer and prepress preserve more quality and use less aggressive compression. Some PDFs are already well-optimized; they may not compress much. Text-only PDFs have limited room for compression because text is already efficient. The tool shows you the before and after sizes so you can decide whether the result meets your needs. For sensitive documents, be aware that processing occurs on the server; use only for files you are comfortable uploading.

Who Benefits from This Tool

Anyone who needs to email or upload PDFs and hits size limits benefits from Compress PDF. Professionals sharing reports, proposals, or presentations often encounter attachment limits. Students submitting assignments to learning management systems face upload caps. Archivists reducing storage needs can shrink older scans. Designers preparing web-ready PDFs use it to optimize for fast loading. Small business owners sending invoices or contracts by email find it useful. The ebook level is a good default for most use cases: it provides substantial size reduction while keeping quality acceptable for reading and casual printing.

Key features

Four Compression Levels

Screen: Maximum compression, typically 70–90% smaller, 72 DPI images. Best for on-screen only. Ebook: Balanced, typically 40–60% smaller, 150 DPI. Recommended for most documents. Printer: High quality, typically 20–40% smaller. Good for printing. Prepress: Minimal compression, typically 5–15% smaller. Best quality for archiving.

Local and URL Input

Upload a PDF from your device or paste a URL and add it to fetch a PDF from the web. Both paths produce a compressed file for download. Mixing is not needed for compression; you process one file at a time.

Ghostscript Engine

Uses Ghostscript with PDFSETTINGS for consistent, reliable compression. Industry-standard engine used in many professional tools. Shows original size, compressed size, and percent saved.

How to use

1. Upload a PDF from your device or enter a URL and click Add to fetch the PDF. Select the file to compress if multiple are present.
2. Choose compression level: screen, ebook, printer, or prepress. Ebook is recommended for most cases.
3. Click Compress. Wait for processing. Processing time depends on file size and server load.
4. Download the compressed PDF when ready. Use Sample to try with a demo file, or Reset to clear and start over.

Common use cases

• Reducing PDF size for email attachments to stay within limits
• Preparing documents for web upload or online forms
• Shrinking scanned documents for storage or sharing
• Archiving with smaller files to save disk space
• Meeting form or portal size limits (e.g. 5 MB max)
• Speeding up uploads and downloads of large documents
• Preparing PDFs for mobile viewing with smaller file sizes
• Converting high-resolution scans to web-friendly size

Tips & best practices

Start with ebook for most documents. It provides a good balance of size and quality. Use screen only when quality is unimportant and you need maximum reduction. Use printer or prepress when you need to print or archive at high quality. Image-heavy PDFs compress more than text-only; if your file does not compress much, it may already be optimized or mostly text. Always check the result before discarding the original: open the compressed file and verify text is readable and images are acceptable. For important documents, keep the original until you confirm the compressed version meets your needs.

Limitations & notes

Compression is lossy at screen and ebook levels: image resolution is reduced. Some PDFs (already optimized or mostly text) may not compress much. Very large files may take longer to process. The server must have Ghostscript installed. Processing occurs on the server, so sensitive documents are uploaded; consider your organization's policies. Some PDFs with complex structures, forms, or embedded fonts may behave differently. Interactive elements may not always be preserved perfectly.

FAQs