PDF Compressor Online
Reduce PDF file size by recompressing embedded images — instantly, entirely in your browser. Nothing is ever uploaded.
Total Privacy — We Don't Save It Anywhere (0 Uploads Policy)
Your PDF is never uploaded in the first place. The entire compression process — loading the document, identifying embedded images, recompressing them, rebuilding the PDF — happens locally, inside your own browser, on your own device.
About the PDF Compressor
A PDF compressor online free tool should do one thing well: take a PDF that's too large — for an upload portal, an email attachment, a KYC form with strict size limits — and shrink it without destroying the content inside. That's exactly what this tool does. It works by finding the embedded images inside your PDF (the usual cause of a large file) and recompressing them using a professional-grade JPEG encoder, entirely in your browser.
How PDF Compression Works
Why Some PDFs Compress More Than Others
A PDF's file size comes from four sources, in typical order of impact: embedded images (usually the largest contributor, especially for scanned documents), uncompressed internal object streams, embedded fonts, and metadata/unused resources. This tool targets the first two — which give the most size reduction for the least trade-off.
Complete Privacy, By Architecture
Unlike online PDF compressors that require uploading your document to a server, this tool never transmits your file anywhere. Every step — parsing the PDF, extracting images, recompressing them, rebuilding the document — runs locally in your browser using WebAssembly and Web Workers.
Frequently Asked Questions
Will this work on any PDF?
Yes — the tool can open any standard PDF. However, the amount of compression depends on what's inside. Scanned documents and image-heavy PDFs typically see the largest reduction. Text-based PDFs are already very compact and may see minimal change.
Is my PDF uploaded anywhere?
No. Your PDF is never transmitted to any server. The entire compression process runs locally in your browser — your file never leaves your device.
Can I compress a scanned document?
Yes — this is exactly where this tool works best. Scanned documents are essentially images stored inside a PDF, which makes them the primary target for recompression.
What's the difference between Light, Recommended, and Maximum?
These control how aggressively the embedded images are recompressed. Light preserves the most image quality but produces a larger file. Maximum creates the smallest file but may show more compression artifacts on photos. Recommended is the best balance for most use cases.
Does this change my text or fonts?
No. This tool only recompresses the embedded images inside the PDF. Text, fonts, vectors, and page layout remain completely untouched.