Edit a PDF on a Mac

Most people asking how to edit a PDF on a Mac want to change something that is already written: a date, an amount, a name, a typo. Preview, the app that opens PDFs on every Mac, cannot do that. The editor above can, on a MacBook Air, a MacBook Pro, an iMac or a Mac mini alike, because it runs in the browser rather than as an app for one version of macOS.

1. Drag the PDF from Finder onto the editor, or click to choose it. Files up to 50 MB open.
2. Move the pointer over the page. Every line you can change is outlined.
3. Click a line, type the new words and press Return. Press Escape to keep it as it was, or clear the line to delete it.
4. To write somewhere new, choose Add text and click where the line should start.
5. Click Download PDF. The edited copy, with “-edited” added to its name, goes where your browser saves downloads, usually the Downloads folder.

Your original file is not changed. If you want the edited version to replace it, move the copy back into the folder in Finder and rename it.

Preview is a good place to mark up a PDF. Open the file, click the Markup button in the toolbar, and you can add a text box, highlight or underline, draw shapes and arrows, and sign with your trackpad or a photo of your signature. In the sidebar you can drag page thumbnails into a new order, rotate them, or delete pages. That covers a lot of what people mean when they search for how to edit a PDF in Preview.

What Preview cannot do is change text that is already in the document. You cannot click the word “2024” on an invoice and turn it into “2025”. The usual workaround is to draw a white rectangle over the old words and put a text box on top. It looks right on screen, but the old words are still in the file. Anyone can select them, copy them or find them with search, and the box can be moved away. For a price, a name or an address, that is not really an edit.

When you change a line in this editor, the characters of that line are deleted from the page, and the new text is written on the same baseline in the same size and colour. Pictures, table lines and background colours under the text are left alone. Searching or copying from the downloaded PDF, in Preview or anywhere else, finds only the new words.

The new words use the closest standard font: a sans-serif face for fonts like Helvetica or Arial, a serif face for fonts like Times or Georgia, and a monospaced face for code and forms, with bold and italic kept. Most PDFs carry only the letters they use, so the original font often cannot write new ones. On invoices, letters and forms the difference is usually hard to see.

You edit one line at a time. A PDF stores where each piece of text sits, not which lines make a paragraph, so a longer line does not push the next one down. Short corrections fit without touching anything else. For a whole new paragraph, edit the original document in Pages or Word and export a fresh PDF.

Searches for the best PDF editor for Mac turn up long lists of apps, many with a subscription. Three questions sort them faster than any ranking. Does it change the existing text, or only cover it up? Does it upload your file to a server, and what happens to it there? And does it cost money for the one change you need today?

This editor answers all three plainly. It removes and rewrites the text itself. It runs inside your browser tab, so the PDF never leaves your Mac and pdfly's servers never receive it. And it is free, with no sign-up. It is built on MuPDF and its source code is public under the AGPL-3.0 license, so anyone can check what it does with a file.

A full desktop PDF editor for macOS is still worth it if you edit PDFs every day, need to reflow paragraphs, fill complex forms or work offline. For fixing a few lines in a contract, a CV or an invoice, a browser editor saves the download and the subscription.

Any PDF saved on your Mac can be edited, whether it came from email, a website or Export as PDF in another app. A scan is different. A page from a scanner, from Continuity Camera or from the Notes app is a picture of text, not text, so there are no lines to click and the editor says so.

You can still use Add text on a scanned page, for example to fill in a printed form that has no form fields. The added text is real text, so it can be searched and copied like any other.

An edited PDF is about the same size as the original. If an email or an upload form still rejects it, use the PDF compressor, or read how to compress a PDF on a Mac when Preview's filter is not enough. To send it in parts, split the PDF by size. To join it with other documents, merge PDFs under a size limit.

One PDF at a time, up to 50 MB. A password-protected PDF cannot be opened; remove the password first, for example by exporting a copy from Preview without encryption. Vertical text is shown but cannot be edited, emoji cannot be typed, and a line that mixes styles is rewritten in the style it starts with.