PDF comp
Your files are safe.
Everything is processed entirely on your device.
PDF
Drag & drop or click to upload
Files are processed locally in your browser
Your files are safe.
Everything is processed entirely on your device.
Drag & drop or click to upload
Files are processed locally in your browser
PDF comp is a completely free web service that reduces the size of your PDF files so they are easier to share, archive, and send. You can use it with nothing more than a modern browser: there is no sign-up wall and no separate desktop installer. The experience is built around three promises you also see on the product surface: it is free to use, it is designed to be safer than typical upload-to-cloud tools, and the actual compression work happens locally on your device. Your PDF bytes are not uploaded to our servers for processing. Rendering, re-encoding, and packaging all run inside your browser’s sandboxed environment, which means sensitive text, personal identifiers, or confidential business content are not shipped over the network for us to store or inspect. That local-first model is especially important for contracts, HR paperwork, research drafts, and any document you would hesitate to place on a third-party file host.
We support files up to about 2 GB, which covers the vast majority of everyday office, school, and hobby PDFs. You can choose between two modes. High Quality prioritises sharpness and readability and typically lands somewhere near thirty to seventy percent smaller than the original, depending on how the source file was built. Maximum Compression prioritises the smallest possible output and often reaches roughly sixty to ninety percent reduction when the document contains lots of raster imagery. Plain text PDFs or files that were already heavily optimised may show modest gains, whereas scanned books, magazines, or camera captures usually leave much more room for savings. To keep layouts predictable for printing and sharing, some steps may normalise pages toward A4-style dimensions, matching the messaging you see elsewhere on the page about consistent paper size.
The workflow is intentionally simple. Pick the mode that fits your scenario, then click the outlined drop zone or drag a file onto it. A progress indicator walks you through the work, and when compression completes you download the new PDF. If something fails, verify that the input is a valid PDF, that it is not corrupted, that it respects the size limit, and that your browser is reasonably up to date. Mobile browsers are supported as well; very large inputs may run slowly or exhaust memory on low-end phones, so Wi-Fi and some free storage headroom are sensible precautions.
From a privacy standpoint we aim to avoid server-side retention of your documents. Still, if you share a computer or hand a tablet to someone else, remember to clear downloads, browser history, or recent files as needed for your own threat model. Regulated industries should reconcile this tool with internal compliance rules before relying on it for medical, legal, or financial records. Because the implementation depends on web platform APIs, keeping your browser patched remains the easiest way to get consistent performance as we iterate on the compressor.
Display advertisements such as Google AdSense or Kakao AdFit may appear near the bottom of the page. They help cover hosting and maintenance costs and are technically isolated from the compression pipeline—ads neither read your PDF nor influence the algorithm parameters. Ad-blocking extensions might hide slots entirely, which can leave empty spacing. This expanded guide is general educational material; it does not guarantee specific compression ratios or legal suitability for every file. Always visually review compressed output, keep backups of originals when stakes are high, and revisit this section if we ship major product updates. Under the same keywords you already saw—free PDF compression, safer local processing, and no mandatory server upload—we will keep improving the tool so lightweight sharing stays accessible to everyone.