Reduce PDF size online using this free tool that shrinks large documents so they meet email attachment limits or upload restrictions. The browser-based compressor works with any standard PDF and delivers a smaller file within seconds. No signup is needed, no watermark is added, and your original content and formatting are preserved throughout the process.
PDF Compressor is a free browser-based tool that reduces the file size of PDF documents by recompressing embedded images. Large PDFs are often created by scanning documents at high resolution or exporting from design software with unoptimised image settings. These files can be impractical to email, upload to web forms with file size limits, or store in large quantities. PDF Compressor addresses this by reprocessing each page as a JPEG image at a user-selected quality level and reassembling the result into a new PDF. Users choose a compression level that balances file size against visual quality, download the compressed PDF, and compare the result against the original. The tool runs entirely in the browser, so no file is sent to a server. It is used by office workers preparing documents for email, students submitting assignments through online portals, and professionals working with file size limits on document management platforms. No account or installation is required.
PDF Compressor works by rasterising each PDF page at a controlled resolution and recompressing the result as JPEG with a user-specified quality factor. This approach is most effective on PDFs that are primarily scanned images, as these have the most redundant pixel data to remove. Text-based PDFs generated from word processors or design tools are already compact, so compression gains are smaller. For scanned documents, compression ratios of 50 to 80 percent are common at medium quality settings, which is usually acceptable for distribution and archival purposes while still being legible on screen and in print. The quality slider lets users find the right trade-off for their specific use case: low compression for archival copies where clarity matters, high compression for fast email attachments or web form submissions where file size is the constraint. Because the tool processes everything in the browser, there are no server-side size limits, no privacy concerns with confidential documents, and no waiting for remote processing queues. For documents that combine scanned images with native text, the compressed output will convert all pages to raster images, which means the resulting PDF will not have selectable text. If searchable text must be preserved, consider extracting and archiving the text content first using PDF to Text before compressing.