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Compress images to reduce file size while maintaining visual quality. Supports lossy and lossless compression with real-time preview and size comparison.
Compress videos up to 90% smaller without visible quality loss. Multiple quality presets, resolution scaling, and bitrate control. Perfect for email, social media, and web uploads.
Add your signature to PDF documents. Draw, type, or upload your signature, then position it anywhere on the page. Perfect for contracts, agreements, and official documents.
Reduce PDF file size while maintaining acceptable quality using our free PDF Compressor, perfect for email attachments, web uploads, and storage optimization. The tool offers multiple compression levels to balance file size and visual quality - choose low compression for near-original quality with modest size reduction, medium compression for good balance, or high compression for maximum size savings with some quality trade-off. File size preview shows predicted reduction before processing, letting you choose the right compression level. Image quality is intelligently managed while text content is preserved as searchable text. The tool is particularly effective for PDFs with many high-resolution images, which can often be reduced by 50-80%. Text-heavy PDFs see more modest reductions since text data is already compact. Fast processing means your PDFs are ready to use in seconds. This is essential for anyone working with file size constraints or wanting to reduce storage costs.
Compress large PDFs to fit within email size limits while maintaining readable quality.
Compress PDF archives to save significant disk space on computers and cloud storage.
Reduce file sizes for faster uploading to websites, cloud services, or document management systems.
Compress PDFs to meet specific file size requirements for submissions or uploads.
Compress PDFs for smooth viewing on mobile devices with limited bandwidth or storage.
Compress entire document libraries or archives to dramatically reduce total storage footprint.
PDF compression involves multiple independent techniques targeting different data types within the document, and understanding each mechanism explains why compression results vary so dramatically between files. The largest contributor to file size in most PDFs is embedded images, which can account for 90% or more of total file size in image-heavy documents. PDF supports several image compression filters: DCTDecode (JPEG compression) for photographs, FlateDecode (zlib/deflate) for lossless compression of images and data streams, JPEG2000 (JPXDecode) for advanced wavelet-based compression, and older methods like LZW and RunLength encoding. A PDF compressor can recompress images using more aggressive quality settings — for example, re-encoding a high-quality JPEG at a lower quality factor or converting an uncompressed image to JPEG.
Image downsampling is another powerful technique. Many PDFs contain images at resolutions far exceeding their display size — a 4000x3000 pixel photograph placed in a 400x300 point area on the page is effectively at 720 DPI when only 150 DPI is needed for screen viewing. Downsampling reduces the pixel dimensions of such images, which dramatically reduces data size since image data scales with the square of the resolution. Bicubic downsampling produces the best visual quality when reducing image dimensions.
Font subsetting is another compression strategy. PDFs often embed complete font files containing thousands of glyphs, but a typical document uses only a fraction of them. Font subsetting strips unused glyphs from embedded fonts, keeping only the characters actually used in the document. A font file that was 500KB for the complete character set might be reduced to 30KB when subsetted to just the Latin characters used in a particular document. This technique is completely lossless — the visual output is identical because only unused data is removed.
Object stream compression, introduced in PDF 1.5, packs multiple small PDF objects into a single compressed stream. Individual objects like page dictionaries, font references, and metadata entries are typically small (a few hundred bytes each), but each one occupies its own space in the file with its own cross-reference entry. Packing them into compressed object streams reduces both the per-object overhead and the total data size through better compression ratios on larger data blocks.
Linearization, sometimes called "fast web view" or "optimization," restructures the PDF so that the first page can be displayed before the entire file is downloaded. While linearization primarily improves perceived loading speed rather than reducing file size, the restructuring process also removes unused objects, consolidates duplicate resources, and eliminates incremental update overhead — all of which contribute to a smaller file. A comprehensive PDF compressor applies all of these techniques in concert, analyzing each component of the document and applying the most effective compression strategy for its data type.
Compression results vary depending on content. PDFs with many high-resolution images can often be reduced by 50-80%. Text-heavy PDFs with few images may see smaller reductions since text data is already compact.
The tool offers multiple compression levels so you can balance size and quality. Low compression preserves near-original quality with modest size reduction, while high compression maximizes size savings with some visible quality loss in images.
Yes, text content is preserved as searchable text during compression. Only embedded images are recompressed to reduce file size. Text, fonts, and vector graphics remain intact.
Since all processing happens in your browser, the limit depends on your device's available memory. Most modern devices can handle PDFs up to several hundred megabytes without issues.
All processing happens directly in your browser. Your files never leave your device and are never uploaded to any server.