Compress PDF — Shrink Any PDF, 100% in Your Browser
Shrink a PDF without sending it anywhere — pick lossless for documents that must stay selectable, or maximum for scans that need the biggest cut.
Compress PDF
Two honest modes — pick what your file needs
Standard re-optimizes the file structure without touching content. Maximum re-renders each page as a JPEG — the biggest cut for scans and image-heavy PDFs, but text is no longer selectable.
How to compress a PDF in your browser
- Choose the PDF. The file is read straight into your tab's memory — there is no upload step and no queue.
- Pick the mode. Standard re-writes the file structure (object streams, stream compression) and is lossless: every word stays selectable and searchable. Maximum renders each page to a JPEG at the quality you choose and rebuilds the PDF from those images.
- Hit compress. The progress bar tracks each page; a 20-page scan finishes in a few seconds to a minute depending on your device.
- Check the before/after sizes and download the smaller file.
Why is the file actually getting smaller?
Most "big" PDFs carry the same image data several times, streams that were never deflated, or object tables far larger than they need to be. Standard mode removes exactly that waste. Maximum mode goes further: a photograph scanned at 300 dpi and stored losslessly can be 3–8× its JPEG size at 100 dpi, which is why scans shrink dramatically in that mode.
Will Standard mode change how my PDF looks?
No. It changes how the bytes are stored, not the content — text, links and fonts render identically. That is the honest trade: it saves less than Maximum mode, and it never costs you the text layer.
What if the compressed file is not smaller?
Some PDFs are already tightly stored, and re-encoding a text-only document as images can even make it bigger. In that case the tool tells you plainly and keeps your original — it will not hand you a larger file and call it a win.
Does it work offline?
Yes. After the page loads, both modes run with the network cable unplugged: the WASM engine and the PDF libraries are local, and your file is never transmitted.
FAQ
- Is my file uploaded to a server? No. The tool runs entirely in your browser — your file never leaves your device. You can verify it yourself: open the network panel and there is no upload request while you work.
- Do I need an account, and is it free? No account and no cost. It is free to use — no signup, no paywall, no daily limit.
- Which browsers does it work in? Any modern browser — Chrome, Edge, Firefox and Safari — on desktop or mobile.
- Is there a size limit? There is no server-side limit because nothing is uploaded. Practical limits come from your device's memory, which comfortably covers normal documents and photos.
- Does it work with encrypted PDFs? Standard PDFs work in every tool. If a file is password-protected, Unlock PDF opens it for you when you have the password, and Protect PDF applies a new 256-bit AES password. No tool bypasses encryption without the key.
Last updated: November 02, 2026 · By Saad, Founder of ToolWow