Reduce PDF file size while maintaining quality. Compress PDF documents for easier sharing, faster uploads, and efficient storage.
Upload your PDF file to compress
PDF compression reduces file size by optimizing images, removing redundant data, and applying efficient encoding. Our tool uses Ghostscript to deliver the best compression ratio while preserving document quality. Text-heavy PDFs see 60-80% reduction, while image-heavy documents can achieve 70-90% smaller files.
PDF compression works by recompressing embedded images with more efficient codecs, removing duplicate font data, optimizing cross-references, and restructuring internal objects. You can choose between lossless compression (preserves exact content) or lossy compression (smaller files with minor quality tradeoffs for images). Grayscale conversion further reduces file size by removing color information.
For maximum compression, use Screen quality (72 DPI) with image downscaling for web-only PDFs. For text-heavy documents, lossless compression typically achieves 40-60% size reduction. Enable grayscale conversion for black-and-white documents to save an additional 20-30%.
No, text quality remains perfectly intact. Compression primarily targets embedded images and redundant metadata. Font data is optimized but not degraded.
Typical compression ratios range from 40-90% depending on content. Image-heavy PDFs see the biggest reductions (70-90%). Text-only documents compress 40-60%.
Yes, all processing happens server-side over HTTPS. Files are encrypted at rest and automatically deleted after 1 hour. We never access or store your document contents.
Screen (72 DPI) for web/email, Ebook (150 DPI) for tablets, Printer (300 DPI) for office printing, Prepress (high quality) for professional print. Higher DPI preserves more detail but produces larger files.
Yes, scanned PDFs often contain high-resolution uncompressed images that compress extremely well — typically 70-90% reduction using image downscaling and JPEG compression.
Yes, all internal links, bookmarks, annotations, form fields, and metadata are preserved during compression. Only image data and structural overhead are optimized.
PDF compression reduces file size through multiple complementary techniques targeting different types of content within the document. Image downsampling reduces the resolution of embedded images — a 300 DPI photo intended for print can be downsampled to 72 DPI for on-screen viewing, reducing its pixel count by approximately 94%. Font subsetting extracts only the specific characters actually used in the document rather than embedding the entire font file, which can reduce font overhead from several megabytes to just a few kilobytes. Grayscale conversion strips all color information from the PDF, converting RGB/CMYK images and page content to monochrome — this is particularly effective for documents scanned in color that only contain black-and-white content. Additional savings come from object stream compression (combining many small PDF objects into compressed streams), cross-reference stream optimization, and removing redundant metadata. Together, these techniques can reduce text-heavy PDFs by 60-80% and image-heavy PDFs by 70-90%.
Our PDF compression offers four quality presets that correspond to specific DPI and compression targets. Screen quality (72 DPI) applies maximum image downsampling and heavy JPEG compression — ideal for email attachments, web uploads, and quick document sharing. Ebook quality (150 DPI) strikes a balance suitable for tablet reading and digital distribution. Printer quality (300 DPI) preserves sufficient resolution for office printing and most business use cases. Prepress quality (highest) maintains near-original image resolution with minimal compression — use this for professional printing when the document must meet commercial print standards. Each preset also adjusts the JPEG compression quality applied to embedded images, with Screen using the highest compression and Prepress using the lowest.
Scanned PDFs offer the greatest compression potential because they consist entirely of high-resolution uncompressed images. A typical scanned document at 300 DPI in full color can be 10-50MB per page. Applying image downsampling to 150 DPI combined with JPEG compression at quality 60 can reduce each page to 100-300KB — a 95-99% reduction. For black-and-white scanned documents, enabling grayscale conversion and using JBIG2 compression (a standard optimized for binary images) can achieve even greater savings. Our tool applies these optimizations intelligently based on your chosen preset.
| Content Type | Typical Reduction | Primary Methods | Best Preset |
|---|---|---|---|
| Text-only documents | 60-80% | Font subsetting, stream compression | Screen |
| Image-heavy PDFs | 70-90% | Downsampling, JPEG compression | Ebook |
| Scanned documents | 80-99% | Downsampling, grayscale, JBIG2 | Screen |
| Presentations (PPT/Keynote) | 50-70% | Image compression, font subsetting | Ebook |
| Print-ready PDFs | 10-30% | Metadata removal, stream optimization | Prepress |
If your document contains no color elements, enabling grayscale conversion removes all color channel data from images and page content. This can reduce file size by an additional 20-30% beyond standard compression.
Image downsampling is the most powerful PDF compression technique. For screen viewing, downsampling to 72-150 DPI is usually sufficient. For documents that will be printed, use 300 DPI or higher to preserve quality while still saving significant space.
Compress images before inserting them into a PDF, use standard web-safe fonts, and avoid embedding unnecessary metadata. Starting with an optimized source document means less work for the PDF compressor.
If you need long-term preservation, PDF/A format strips JavaScript, external references, and encryption that might prevent future access. Combine PDF/A conversion with compression for archival-grade PDFs that are both small and future-proof.
No — text content, fonts (via subsetting), and vector graphics remain perfectly clear after compression. Only embedded images are potentially downsampled. Text is rendered using the same fonts at the same resolution as the original.
Scanned PDFs offer the greatest compression potential — typically 80-99% reduction. A 50MB scanned document can often be reduced to 1-5MB using Screen quality with image downsampling and JPEG compression, while remaining perfectly readable.
Lossless PDF compression uses object streaming and font subsetting without altering image data — quality is preserved identically. Lossy compression downsamples images and applies JPEG compression to embedded images, which can introduce artifacts but achieves much smaller files.
Yes — all internal links, bookmarks, PDF form fields, annotations, and document structure are preserved during compression. Only the storage efficiency of images and metadata is optimized.
Our tool can compress non-encrypted PDFs. If your PDF is password-protected, you must remove the password protection first, compress the file, then re-apply protection. This is a security measure to prevent unauthorized processing of protected documents.