The simplest way to edit a PDF on Mac is Preview, the app already built into your system
You do not need to buy software or download anything. Open the PDF in Preview — the default app that opens when you double-click a PDF file — and you can add text, draw, highlight, erase, and rearrange pages. For most everyday edits like filling in a form, adding a signature, or marking up a document, Preview handles the job.
If you need to do something Preview cannot handle — like changing text that was already in the PDF, combining multiple PDFs into one file, or extracting specific pages — you have other options. Some are free, some cost money, and some work only online. This guide covers what each tool can and cannot do, so you can pick the right one for what you are trying to accomplish.
Key Takeaways
- Preview, which comes free with every Mac, can add text boxes, signatures, highlights, and drawings to any PDF without installing anything.
- To edit text that already exists in a PDF, you need a different tool — Preview cannot change the original words, only add new content on top.
- macOS also includes a Markup toolbar in Mail and Messages that lets you edit PDFs without opening a separate app.
- For combining PDFs, extracting pages, or changing file size, Preview has built-in options in its Tools menu.
- Paid tools like Adobe Acrobat Pro and free alternatives like PDFtk offer more advanced features, but most people never need them.
Using Preview to add text, signatures, and highlights
Open your PDF in Preview by double-clicking it, or by right-clicking it, selecting "Open With," and choosing Preview. At the top of the window, click the Markup toolbar icon — it looks like a pen tip in a circle. A row of tools appears below the toolbar.
The tools you will see are: a text box (the "A" icon), a signature tool, a highlighter, a pen for drawing, a magnifying glass, and a shape tool. Click the text box icon and then click anywhere on the PDF to add a new text box. Type what you need. To sign a PDF, click the signature icon, then "Signature," then choose a signature you have already created in Preview or create a new one by signing on your trackpad.
To highlight, underline, or strike through text that already exists, click the highlighter icon, choose your style from the dropdown, and drag across the text. The pen tool lets you draw or write freehand anywhere on the page. When you are done, press Command+S to save your changes directly to the original file, or Command+Shift+S to save as a new file with a different name.
Editing text that already exists in the PDF
Preview cannot change words that were already printed into the PDF. If you need to edit the actual text — for example, changing a name, date, or amount on a form — Preview is not the right tool. You have three options: use a paid tool like Adobe Acrobat Pro, convert the PDF to a different format first, or use an online editor.
Adobe Acrobat Pro costs about $180 per year and can edit text directly in most PDFs. If the PDF was created from a scanned image rather than a digital document, even Acrobat cannot edit the text without using optical character recognition (OCR), which is a separate process. Online tools like Smallpdf, ILovePDF, and PDFtk allow you to upload a PDF and edit text in your web browser, though you are uploading your file to someone else's server. If the PDF contains sensitive information, this may not be the right choice.
Combining, splitting, and resizing PDFs in Preview
Preview can combine multiple PDFs into one file, extract specific pages, and reduce file size — all without leaving the app. To combine PDFs, open the first PDF in Preview, then go to Edit menu and select "Insert" (or "Insert Page from File" depending on your macOS version). Choose the other PDFs you want to add and they will be inserted after the current page.
To extract pages, open the PDF, go to View menu, and click "Thumbnails" to see all pages as small images on the left side. Select the pages you want to keep by clicking them while holding Command (to select multiple non-consecutive pages) or Shift (to select a range). Then go to File menu and select "Export Selected Pages." To reduce file size, go to File menu, select "Export," and in the Quartz Filter dropdown, choose "Reduce File Size."
Using Markup tools in Mail and Messages
If someone sends you a PDF in Mail or Messages, you can edit it without opening Preview separately. In Mail, click the PDF attachment, then click the Markup icon (the pen tip in a circle) that appears in the top right corner of the preview. In Messages, tap and hold the PDF, select "Markup," and the same tools appear. You can add text, signatures, highlights, and drawings the same way you would in Preview, then send the edited version back.
This is faster than downloading the attachment, opening Preview, editing, saving, and then attaching it again. The edited PDF stays in the conversation, so both people can see the changes without extra steps.
When to use paid tools or online editors
If you regularly need to edit text inside PDFs, change fonts, or work with forms that require complex edits, a paid tool saves time. Adobe Acrobat Pro is the industry standard and works on both Mac and Windows. It costs about $180 per year, though you can sometimes find discounts. Acrobat can also fill forms automatically, extract data from multiple PDFs, and convert PDFs to other formats like Word or Excel.
Online editors like Smallpdf, ILovePDF, and Sejda let you edit PDFs in your web browser without installing anything. Most offer a free tier with limits on how many files you can edit per month, and a paid tier for unlimited use. The trade-off is that your file is uploaded to their server, which matters if the PDF contains private information. If you only edit PDFs occasionally and they do not contain sensitive data, an online tool may be enough.
Free Mac apps for more advanced PDF work
If you want a free alternative to Adobe Acrobat Pro, a few options exist. PDFtk (also called PDFtk Server) is free and runs from the command line — it is powerful but requires typing commands rather than clicking buttons, so it is better for people comfortable with Terminal. Coherence X is a free app that can combine PDFs and extract pages with a simple interface, though it has fewer features than Preview.
For most people, Preview is enough. It handles the tasks that come up most often — signing documents, filling forms, highlighting text, and combining files — without paying anything or learning new software. The only reason to switch is if you need to edit the actual words in a PDF, and in that case, the choice depends on how often you do it and whether the file contains sensitive information.
Frequently Asked Questions
Can I edit a PDF that is password-protected?
Preview can open a password-protected PDF if you know the password, but it cannot remove the password protection itself. If the PDF is locked against editing, Preview will let you view it and add markup, but you cannot save changes. To remove password protection, you need Adobe Acrobat Pro or an online tool that handles encrypted PDFs.
Why does my edited PDF look different when I open it again?
This usually happens when fonts are not embedded in the PDF. Preview uses the fonts available on your Mac, so if the original PDF used a font you do not have installed, Preview substitutes a different one. The content is still there, but it may look slightly different. Saving as a new file sometimes helps, but the real fix is using a tool that embeds fonts, like Adobe Acrobat Pro.
Can I undo changes after I save a PDF in Preview?
Once you save a PDF in Preview, the changes are permanent and cannot be undone. If you think you might want to go back, use Command+Shift+S to save as a new file instead of Command+S. This keeps the original unchanged and creates a new version with your edits.
What is the fastest way to sign multiple PDFs?
Create your signature once in Preview (Markup toolbar, signature icon, "Manage Signatures"), then open each PDF and click the signature tool. Your saved signature appears and you can click to place it on each page. This is faster than signing each one from scratch, and it keeps your signature consistent across all documents.
Can Preview convert a PDF to Word or another format?
Preview cannot convert PDFs to Word, Excel, or other formats. It can only export as PDF or image formats like JPEG and PNG. To convert to Word or Excel, use Adobe Acrobat Pro, an online converter, or a dedicated conversion tool. If the PDF is a scanned image, conversion tools will use OCR to read the text, which is less accurate than converting a digital PDF.