Which Free PDF Tool Do You Actually Need?
Seven questions, about a minute, and you get pointed at the right tool for the job in front of you. The first question does most of the work, since compressing and merging and converting are genuinely different operations. The rest tailor the advice to your file size, your privacy needs, and whether this is going to someone else. Nothing is stored and there's no signup.
Sources: PDF is defined by the ISO 32000 family of standards, published as ISO 32000-1:2008 and continued as ISO 32000-2 for PDF 2.0. Technical documentation on the format, including how compression and digital signatures work inside a PDF, is published by the PDF Association, the industry body for the format. Compression expectations quoted here reflect what structural optimisation in a browser can achieve, which is documented on our own compress tool page.
Questions people ask before picking a tool
Which free PDF tool do you actually need?
It depends almost entirely on the job. Compressing, merging, splitting, and converting are four different operations with four different tools, and picking the wrong one wastes time. This quiz asks what you are trying to do first, then adjusts the advice based on file size, how private the document is, and whether you need to send it somewhere. The recommendation links straight to the tool.
Do free PDF tools upload your file to a server?
Many do, and that is the main thing to check before using one. Every tool on this site runs in your browser using JavaScript, so the file is read into memory on your own machine and never transmitted. If you are handling contracts, medical records, or anything covered by a confidentiality agreement, browser-based processing removes the question of what a server did with your document.
Why does compressing a scanned PDF barely shrink it?
Because a scanned page is already a compressed image, usually JPEG, sitting inside the PDF container. Structural optimisation removes unused objects and tidies the file, but it cannot squeeze an image that is already squeezed. Getting a scan meaningfully smaller means recompressing the images themselves at lower quality, or rescanning at a lower resolution such as 200 DPI instead of 600.
Is PDF an open standard?
Yes. Adobe created the format, but PDF was published as an open ISO standard in 2008 as ISO 32000-1, and PDF 2.0 is ISO 32000-2. That means anyone can write software that reads and writes PDF without permission or licence fees, which is why free browser-based tools like these can exist at all. The PDF Association maintains public documentation on the format.
Can free tools add a legally valid signature?
Pasting a picture of your handwriting onto a page is not a digital signature. It is an image, and anyone can move or copy it. A digital signature in the technical sense uses a certificate to cryptographically bind the signature to the document, so any later edit breaks it. For legal or financial documents, that distinction matters, and free image-stamping tools do not provide it.