Shrink a PDF file without sending it anywhere.

UtilForge makes it. UtilForge is a website of free cybersecurity tools and small calculators. The About page explains why the tools were made, and the Contact page is the way to reach us.

A person does not have to take UtilForge's word for it, so here are things to check. This page does not ask for payment, an account or card details. The compressor itself is free. UtilForge also sells optional packs of tools separately, on Gumroad, and this tool works without them. The page carries a security setting (a Content Security Policy, a rule the browser enforces) that forbids the page from sending anything out, so your PDF file cannot be uploaded from here. To test it, open the page, switch the internet off, choose a PDF file and compress it. It carries on working, because the page and its PDF file libraries are already on your device.

Nothing is kept. While the page is open, your PDF files and the compressed copy sit in the memory of the browser tab. The page does not use cookies, local storage, session storage or IndexedDB (the browser's built-in database), and it puts nothing about your file in the page address, so there is no link that holds your values. Closing the tab, or pressing Reset, drops the copies from memory. The one thing that stays is a file you save yourself: when you press Download, your browser saves a new file named after the original with -compressed added, for example report-compressed.pdf, in your downloads. That saved file is yours and the page does not track it. Your original file is never changed.

No. The compressor is free, and you can start straight away. UtilForge also sells optional packs separately, such as Redaction Studio ($29 to own) and Family Safety Tools (pay what you want, including nothing). This tool does not need either.

Strong, Balanced, Light and Target size work by turning every page into a Joint Photographic Experts Group picture (a picture format that squeezes images by dropping fine detail). That makes the file smaller, but a picture of a page has no text to select or search. To keep the text, tick Lossless rewrite only. It rewrites the file, clears the title, author and producer from the file's main details record, and keeps text, fonts and drawings as they are. It is not a privacy clean-up: a second copy of those details, comments and attached files can stay in the file. For that, use the Remove metadata from a PDF file tool. It usually saves much less, often only a few per cent.

Not exactly. Target size mode tries a series of Joint Photographic Experts Group quality levels and, if needed, smaller picture sizes, and shows the size it reached next to your target. Joint Photographic Experts Group quality moves in steps, so an exact number of bytes is not promised. If the plain rewrite is already under your target, that file is used, so the text is kept. If nothing reaches the target, the page keeps the smallest result it found and says so. The smallest target you can enter is 20 kilobytes.

No. The work stays in the browser tab, with libraries that load from the same site. People who ask about private PDF file compression usually mean exactly this. To check it yourself, turn off the internet and see that it still works.

The picture methods redraw each page as an image, so text can no longer be selected or searched. Use the lossless rewrite when you need to keep selectable text.

No, by design. Unlock the file somewhere else only if you have the right to, then compress the unlocked copy here on your device.

The limit is the tab’s memory. Very large or picture-heavy PDF files can freeze or fail in the browser. That is a known limit, not a quota set by a server.