Make a PDF smaller in your browser. Choose a lossless clean-up that keeps text selectable, or a stronger mode that turns each page into a JPEG image. Your file never leaves your device.
There are two modes. Lossless clean-up copies every page into a fresh document with pdf-lib (MIT) and saves it with object streams. That drops unused objects and packs the structure tighter, without touching text or images, so savings are usually modest (often 0–20%).
Strong mode renders each page with PDF.js (Apache-2.0) at the resolution you pick, saves it as a JPEG and builds a new PDF from those images. Scanned documents and image-heavy files often shrink a lot; text-only files can get bigger. Both libraries are served from this site.
Open your browser's developer tools (F12, or Cmd+Option+I on a Mac), switch to the Network tab and use the tool. You'll only see this page and its scripts loading from toolsthatdontupload.com, and no request carrying your file. The page is also served with a Content-Security-Policy of connect-src 'none', which tells your browser to block any attempt by the page to send data.
After the page has loaded you can also switch off Wi-Fi; the tool keeps working because nothing it needs is fetched later.
The same job is available as a REST endpoint, /api/pdf-merge, and through the MCP server. Unlike this page, the API receives your input on our server; it is processed in memory and not stored. File endpoints allow a limited number of anonymous calls per day; a free key raises that.
curl -X POST https://toolsthatdontupload.com/api/pdf-merge -F "files=@a.pdf" -F "files=@b.pdf" -o merged.pdfImage to PDF · Delete PDF Pages · Reorder PDF Pages · PDF Sign · PDF to Image · All tools