How to Edit a PDF on Mac: The Complete Guide
If you own a Mac, you already own a capable PDF editor — you just might not know it. Whether you need to fill out a form, sign a contract, add a comment, rearrange pages, or make more substantial changes like editing text and images, your Mac has tools built right in that can handle most everyday tasks without spending a dime. And when those built-in tools aren’t enough, there’s a healthy ecosystem of third-party apps that can fill the gaps.
This guide walks through everything from the basics of opening and marking up a PDF in Preview, to more advanced edits, to when it makes sense to reach for a dedicated PDF editor like Adobe Acrobat or one of its many alternatives.
Why PDFs Are Trickier to Edit Than They Look
Before diving into the how-to, it helps to understand why PDFs behave differently than a Word document or a Google Doc. PDF stands for “Portable Document Format,” and it was designed by Adobe in the early 1990s with one primary goal: to make a document look exactly the same no matter what device, operating system, or printer it’s opened on. To achieve that consistency, PDFs don’t store content the way a word processor does, as a flowing stream of editable text. Instead, they store the precise position of every character, line, and image on the page, almost like a printed photograph of the document.
That’s great for preserving formatting, but it’s exactly why editing a PDF can feel clunky. When you change a sentence in a PDF, you’re not just retyping text; you’re manipulating a snapshot. This is also why some PDF edits (like adding a signature or a comment) are simple, while others (like reflowing a paragraph after adding a sentence) can get messy, especially in documents that were originally scanned as images rather than created digitally.
With that context, here’s how to handle nearly any PDF editing task on a Mac.
Method 1: Use Preview, macOS’s Built-In PDF Tool
Every Mac comes with Preview, and most people only use it to view images. But Preview has a surprisingly robust set of PDF editing tools baked in, and for a large percentage of everyday tasks, it’s all you’ll need.
Opening a PDF in Preview
Any PDF you double-click on a Mac will typically open in Preview by default.
Adding Text to a PDF
To insert new text into a PDF, such as filling out a form that isn’t interactive, or adding a note in a blank area:
- Open the PDF in Preview.
- Click the Markup toolbar icon (it looks like a pen tip inside a circle) in the top-right corner of the window. If you don’t see the toolbar, go to View > Show Markup Toolbar.
- Click the “Text” icon, which looks like an “A” inside a small box.
- A text box will appear on the page. Drag it into position and type your content.
- Use the formatting controls in the Markup toolbar to adjust the font, size, and color.
This is especially useful for older PDFs, like a scanned rental agreement or an old application form, that don’t have interactive fields.
Filling Out PDF Forms
Many PDFs, particularly official forms, are built with interactive fields. Preview can detect these automatically.
- Open the PDF.
- Click into any field that’s outlined or highlighted, and your cursor will automatically become a text cursor.
- Tab between fields to move through the form quickly.
- For checkboxes, simply click to toggle them.
If Preview doesn’t recognize the form fields (which can happen with certain scanned or oddly formatted PDFs), you can use the manual text tool described above to place text wherever it’s needed.
Signing a PDF
One of the most common reasons people need to edit a PDF is to add a signature, and Preview makes this remarkably easy without needing to print, sign, and re-scan anything.
- Open the PDF and click the Markup toolbar icon.
- Click the signature icon, which looks like a cursive signature line.
- Choose to create a new signature using either your Mac’s trackpad, your Mac’s camera (hold up a signature written on white paper), or your iPhone or iPad if it’s signed into the same Apple ID.
- Once created, your signature is saved and can be reused. Click it, then drag and resize it into place on the document.
Highlighting, Underlining, and Adding Comments
For reviewing documents, Preview’s annotation tools work similarly to Adobe’s:
- Select the text you want to mark up.
- In the Markup toolbar, choose Highlight, Underline, or Strikethrough.
- To leave a comment, click the speech-bubble icon and click on the spot in the document where you want the note to appear, then type your comment.
Drawing and Adding Shapes
Preview also includes a simple drawing tool and shape library, useful for circling important sections, adding arrows, or sketching a quick diagram.
- Click the Markup toolbar icon.
- Choose the sketch tool (pencil icon) to draw freehand, or select from the shape options (rectangle, oval, line, arrow) for clean geometric marks.
- Adjust color, line thickness, and fill using the options that appear.
Rearranging, Deleting, and Adding Pages
Preview handles page-level editing well, too.
- Open the PDF and go to View > Thumbnails (or press the sidebar icon) to see a scrollable list of every page.
- To delete a page, click its thumbnail and press Delete.
- To reorder pages, simply drag thumbnails into the order you want.
- To insert pages from another PDF or an image, open both files’ thumbnail views side by side, then drag the pages from one window into the other.
- To rotate a page, select its thumbnail and use Tools > Rotate Left or Rotate Right.
This makes Preview genuinely useful for tasks like combining multiple scanned pages into a single PDF, or removing a blank cover page before sending a document off.
Redacting Sensitive Information
If you need to permanently black out sensitive information, be careful: simply drawing a black rectangle over text in Preview does not remove the underlying text, it just visually covers it, and that text can often still be selected, copied, or extracted. For true redaction, you’ll want to use the dedicated redaction feature in a tool like Adobe Acrobat (covered below), or flatten the black-box image using image conversion. If privacy is genuinely important, don’t rely on a basic markup box.
Saving and Exporting
Once you’ve finished editing, use File > Save to overwrite the original, or File > Export to save a new copy, optionally changing the format, compressing the file size, or applying encryption with a password.
Method 2: Editing Actual Text and Layout
Preview is excellent for annotations, signatures, and page management, but it isn’t built to let you click into a paragraph and rewrite a sentence the way you would in Word. If you need to genuinely edit the underlying text and layout of a PDF, meaning changing a word, fixing a typo, or adjusting a paragraph, you have a few options.
Option A: Convert the PDF Back to a Word Document
For text-heavy PDFs, the most practical free approach is often to convert the file to a Word document, make your edits there, and export it back to PDF.
- Open the PDF in Preview or another viewer to confirm it’s a text-based PDF (not a scanned image).
- Use Word itself: open Word, go to File > Open, select the PDF, and Word will convert it into an editable document automatically.
- Make your edits as you normally would in Word.
- When finished, go to File > Save As and choose PDF as the format to export it back.
This method works best for simple, mostly-text documents. Complex layouts with lots of graphics, multiple columns, or precise design elements often don’t convert cleanly, and you may end up spending more time fixing formatting than you saved.
Option B: Use a Dedicated PDF Editor
For more reliable text editing directly inside the PDF (without a round-trip conversion), a purpose-built PDF editor is the better choice. Popular options for Mac include:
- Adobe Acrobat Pro: The industry standard, with the most complete toolset, including reliable text editing, real redaction, form creation, and batch processing. It’s subscription-based and the most expensive option, but it’s the most dependable for professional or high-volume use.
- PDFpen :A long-standing Mac-native app well regarded for its clean interface and solid text-editing, OCR, and form-building tools.
- PDF Expert: A polished, Mac-and-iOS-friendly option with strong annotation, editing, and form tools, and a straightforward interface.
- PDFelement ): A budget-friendly alternative to Acrobat with a similar feature set, including OCR and batch conversion.
Across these apps, the general workflow for editing text is similar:
- Open the PDF in the app.
- Select the “Edit” or “Edit Text & Images” tool.
- Click directly into a paragraph; the app will detect the text block and let you type as you would in a word processor.
- Adjust font, size, and spacing as needed, since these apps try to preserve the original formatting automatically, but it’s worth double-checking after any edit.
- Save or export your changes.
Editing Scanned PDFs (Image-Based Documents)
If your PDF was created by scanning a physical document, there’s no underlying text to edit at all, just a picture of a page. Before you can edit the words, you need Optical Character Recognition (OCR) to convert the image into recognizable, editable text.
Most of the dedicated editors mentioned above (Acrobat, PDFpen, PDF Expert, PDFelement) include built-in OCR tools. The general process is:
- Open the scanned PDF in your chosen app.
- Look for an “OCR” or “Recognize Text” option, usually under a Tools or Edit menu.
- Run the recognition process; the software will scan the image and generate a layer of selectable, editable text behind it.
- Once OCR is complete, you can use the app’s text-editing tool as you would with any other PDF.
OCR accuracy depends heavily on scan quality: a crisp, high-resolution scan of clean typed text will convert far more accurately than a blurry photo of handwritten notes.
Method 3: Editing PDFs for Free Online
If you only need to make a one-off edit and don’t want to install anything, browser-based tools can work in a pinch. Sites like Adobe’s own free online tools, Smallpdf, and PDFescape let you upload a file, make basic edits such as adding text, merging documents, or compressing file size, and download the result.
A few things worth knowing before using an online PDF editor:
- Privacy matters. Any file you upload to a third-party website is, technically, in someone else’s hands, even briefly. Avoid uploading documents with sensitive personal information, financial details, or confidential business content to free online tools unless you’ve read and trust their privacy policy.
- Feature limits. Free tiers usually cap file size, the number of edits per day, or restrict you to watermarked exports unless you pay.
- No installation needed, which makes these tools genuinely convenient for quick, low-stakes tasks like merging two PDFs or rotating a page.
Choosing the Right Approach for Your Task
With so many options, it helps to match the tool to the job:
- Signing a document or filling out a simple form → Preview is fast, free, and already on your Mac. | Adding comments, highlights, or reviewer notes → Preview’s Markup tools handle this well.
- Rearranging, merging, or deleting pages → Preview’s thumbnail sidebar is quick and intuitive.
- Editing a sentence or two in a simple text-based PDF → Try opening it directly in Word first; it’s free and often good enough.
- Frequent or complex text editing, professional documents, or true redaction → Invest in a dedicated app like Acrobat, PDFpen, or PDF Expert.
- A scanned document with no selectable text → Use OCR in one of the dedicated editors before attempting any text edits.
- A single quick edit and no software installed → A reputable online PDF tool will do, as long as the content isn’t sensitive.
Tips
- Always work on a copy. Before making significant edits, especially to something like a signed contract or an official record, duplicate the file first (Command+D in Finder) so you always have the unedited original to fall back on.
- Check file size after editing. PDFs with lots of images or heavy annotations can balloon in size. Most editors, including Preview, offer a “Reduce File Size” or “Quantize” export option under File > Export, which is handy before emailing a large document.
- Password-protect sensitive PDFs. If your edited PDF contains private information, Preview lets you add password protection during export: go to File > Export, check “Encrypt,” and set a password. Dedicated editors offer more advanced permission controls, such as restricting printing or copying.
- Keep formatting expectations realistic. No PDF editor, free or paid, perfectly recreates complex desktop-publishing layouts. If a document has intricate multi-column designs, unusual fonts, or embedded interactive elements, expect some manual cleanup regardless of which tool you use.
Conclusion
For the vast majority of everyday PDF tasks on a Mac, signing documents, filling out forms, leaving comments, or rearranging pages, Preview is genuinely all you need, and it’s already installed on every Mac. It’s free, fast, and handles the basics with surprisingly little friction.
Where Preview falls short is in true text editing and advanced features like real redaction or batch processing. For those needs, a dedicated PDF editor, whether that’s the professional-grade Adobe Acrobat or a lighter, one-time-purchase alternative like PDFpen or PDF Expert, will save time and produce cleaner results. And for scanned documents, OCR is the essential first step before any text editing can happen at all.
Start with what’s built in. Only reach for something more powerful once you’ve bumped up against Preview’s limits, and you’ll likely find that most of your PDF editing needs are already covered by the software sitting quietly in your Applications folder.
