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How to edit a PDF: what you actually need for it

By Alberto Gulotta · Updated 2 September 2026 · 7 min read

How to edit a pdf is a question with three answers, because the word covers three completely different tasks and only one of them is hard. A PDF editor is one of the most expensive things people buy for a job they could do for nothing — not because the paid products are bad, but because the two easy jobs cover most of what the question asks for.

Somebody who wants to highlight a paragraph, somebody who wants to type into a form and sign it, and somebody who wants to rewrite a sentence that was printed into the page are all searching the same words. The first two are free and already installed. The third is genuinely difficult, and it is difficult for a reason worth understanding.

The signature is the part that surprises people, because it is captured rather than drawn with a mouse. Apple documents three ways to make one: “you can capture your signature using your trackpad, the built-in camera on your Mac, or your iPhone or iPad.” The trackpad route has a detail worth knowing — “If your Mac has a Force Touch trackpad, you can press your finger more firmly on the trackpad to sign with a heavier, darker line.” The camera route wants the signature on white paper, held level with the blue line on screen. And the iPhone route hands the signing to a device you can actually write on, with a finger or an Apple Pencil.

Two things follow from that, and both save time. A signature made once is stored and reused: you pick it from a list rather than signing again, and if you use iCloud Drive it is available on your other Macs. And if you keep more than one — a full signature and a set of initials, say — Apple’s instruction is to label them as you create them: “click the Description pop-up menu, then choose a description, such as Initials”. That list is otherwise a row of near-identical squiggles.

Two smaller doors, for the form itself. Since macOS 14.2 Preview can fill contact details in for you from the Contacts app — Apple calls it enhanced AutoFill and attaches a caveat in the same breath: “Not all PDFs support this feature.” And for the form that refuses to be typed into at all, which is the common frustration, the documented answer is not a different application: “If a PDF won’t allow you to type directly into the form, you can add a text box instead.”

On Windows the free route is the browser, and it is more capable than it looks. Microsoft documents Edge’s built-in PDF reader as taking local, online and embedded files, and lists what it can do to them: inking and ink customisation, highlighting, text notes, read aloud. That covers the first of the three jobs entirely, without installing anything.

It also carries one limitation that explains a frustration that looks like user error. Microsoft’s feature list says “Basic form filling (JavaScript forms aren’t supported)”. A great many official forms — tax, immigration, insurance — are built with JavaScript, so they open perfectly and then refuse to accept a single character. Nothing is broken and nothing you do to the browser will fix it: that form needs a reader that runs the script inside it.

The words divide along the same lines. Somebody typing how to edit a pdf is usually mid-task with a deadline. Free pdf editor and pdf editor free come from people who have just been shown a price. Pdf editor online means a browser and probably a work computer that will not let them install anything. Sign pdf, fill out pdf and add text to pdf are the specific jobs underneath the general search, and a pdf annotator is what students and reviewers actually want. Six different needs, and only the last wing of this guide costs money.

That reason is what a PDF is. It was designed to arrive looking the same everywhere, which it does by fixing every mark to a position on a page rather than storing a document that reflows. Editing text inside one is not typing into a document — it is altering a finished page and hoping the rest still fits.

Not covered here. It will not recommend a paid editor before showing you the free route. On this guide that would be close to dishonest: for the two most common tasks the answer is already on the machine, and Microsoft and Apple both document it themselves.

It will not rank the editors yet. That verdict needs paid licences, the same awkward document opened in each, and a published account of what survived — a test rather than a table of ticks.

And it will not tell you a black rectangle removes text. It does not, the words are still in the file underneath, and that mistake has ended careers. The guide about it is short and blunt for that reason. What holds instead is simple: the two most common jobs here are free on every machine sold in the last decade.