Compress PDF
Make a PDF dramatically smaller. Free — no signup, no watermarks.
How it works
- 1Open your PDF and pick a mode: lossless cleanup, or real image re-encoding for dramatic cuts.
- 2Click Compress — the engine loads once and runs entirely on your device.
- 3Compare the before/after sizes and download the smaller file.
Common questions
›How much smaller will my PDF get?
It depends on what's inside. Scans and image-heavy documents often shrink 70–90% in the stronger mode; text-only PDFs are already efficient and shrink modestly. If compression can't beat your original, you get the original back — the output is never larger.
›Which mode should I choose?
Balanced re-encodes images at a quality that's hard to distinguish on screen — right for email and uploads. Strong pushes harder for the smallest file — right for size caps like 2 MB application portals. Neither touches the text, which stays perfectly sharp in both.
›Why does the first compression take a moment to start?
The compression engine (a full PDF processor compiled to WebAssembly) downloads once, then runs locally. That one-time download is what makes it possible to compress on your device instead of uploading your file to a server.
›Are my files uploaded to a server?
No. This tool runs entirely in your browser — the file is opened, processed, and saved on your own device. There is no upload in the code path, which you can verify by watching the network tab, or by loading the page and then switching to airplane mode: the tool still works.