Compress PDF is a free, browser-based PDF optimizer built to shrink PDF file size and make PDF smaller while preserving as much visual quality as possible. Large PDFs are a constant frustration — email providers reject attachments over a few megabytes, web portals enforce strict upload limits, cloud storage fills up quickly, and sharing a 50 MB scan is impractical. This tool solves all of that in a few seconds without uploading your file anywhere.
Choose from three quality presets to match your needs: Maximum Compression delivers the smallest possible file, ideal for archiving or sending through messaging apps; Balanced gives a practical middle ground that works well for most business documents; Minimum Compression trims file size while keeping images and text nearly identical to the original — best for client-facing documents where quality matters.
After compressing, the tool shows you exactly how many bytes were saved and the percentage reduction, so you can decide whether the result meets your needs before downloading. If the compressed file would be larger than the original — which can happen with already-optimised PDFs — the tool warns you instead of forcing a pointless download.
Because everything runs locally in your browser using WebAssembly, your documents are never uploaded to any server. This makes the tool safe for confidential reports, financial statements, legal documents, medical records, and any sensitive material. There is nothing to install and no account required for standard file sizes. If you're preparing a document for delivery, you can also merge several PDFs first, add a watermark for brand protection, or password-protect the compressed result before sending it out.
