The fastest way to edit a PDF on Mac is Preview, the app already on your computer
Open the PDF in Preview (right-click the file, select "Open With", choose Preview). Once it opens, click the markup toolbar icon in the top right — it looks like a pen tip in a circle. From there you can add text boxes, draw, highlight, strike through, or add shapes. When you finish, press Command+S to save your changes directly to the file.
Preview handles the most common edits: adding your signature, filling in forms, crossing out text, and annotating documents. It does not let you rearrange pages, delete text from the original document, or change fonts — those require a different tool. For straightforward mark-ups and signatures, Preview is usually enough and costs nothing.
Key Takeaways
- Preview, built into every Mac, can add text boxes, signatures, highlights, and shapes to any PDF without installing software.
- To edit text that was already in the PDF or rearrange pages, you need a dedicated PDF editor like Adobe Acrobat or a third-party app.
- Saving in Preview overwrites your original file, so duplicate it first if you want to keep an unchanged copy.
- Free web-based PDF editors work on Mac but require uploading your file to the internet, which matters if the document contains sensitive information.
Adding text, signatures, and markup in Preview
Once the markup toolbar is open in Preview, you have five main tools. The text box tool (the letter "A") lets you click anywhere on the page and type new text — useful for filling in forms or adding notes. The signature tool (the pen) lets you sign with your trackpad or mouse; if you have signed a document before on your Mac, Preview remembers that signature and you can insert it with one click.
The highlight, underline, and strikethrough tools work like a marker — click the tool, then drag across the text you want to mark. The shape tool adds rectangles, circles, or arrows. All of these changes save to the file when you press Command+S, and Preview will ask whether you want to save as a new file or replace the original.
Editing text that was already in the PDF
Preview cannot edit or delete text that was part of the original PDF. If you need to change the actual words in the document — not just add notes on top — you need a different tool. Adobe Acrobat (the paid version, not the free Reader) can do this, as can Coherence X, PDFpen, or Nitro PDF.
These apps let you select existing text and rewrite it, delete paragraphs, or change fonts. They cost between $80 and $200 for a one-time purchase, or $15 to $25 per month for a subscription. If you only need to edit text occasionally, a free web-based editor like Smallpdf or ILovePDF works on Mac — you upload the file, make changes in your browser, and read the result. The trade-off is that your file goes to someone else's server.
Rearranging, deleting, or extracting pages
Preview can rotate pages and delete them, but the process is clunky. Open the PDF, go to View menu, select "Thumbnails", and a sidebar appears showing every page. Right-click a page thumbnail and you can delete it or rotate it. To rearrange pages, you have to delete and re-add them in the right order, which is slow for long documents.
If you regularly need to rearrange pages, extract certain pages into a new file, or merge multiple PDFs, use a dedicated tool. PDFpen, Coherence X, and Adobe Acrobat all let you drag pages to reorder them. Many free web tools also handle this — Smallpdf, ILovePDF, and PDF.io all let you upload a PDF, rearrange pages by dragging, and read the result. Again, your file is uploaded to their servers.
Filling out forms and saving the result
If the PDF is a form with fillable fields (text boxes, checkboxes, dropdown menus), Preview can fill them in. Click a field and type or select your answer. When you save, the filled-in form saves as a new PDF with your answers included. This works for most government and business forms.
Some older forms are not fillable — they are just images of a form with blank lines. Preview cannot fill these in automatically; you have to use the text box tool to type over the blank lines, which looks less polished. If you receive a lot of non-fillable forms, a tool like PDFpen or Adobe Acrobat can convert them to fillable forms, though this takes extra time and is usually not worth it unless you use the same form repeatedly.
Comparing your options
| Tool | Cost | Add text and signatures | Edit existing text | Rearrange pages | Fillable forms |
|---|---|---|---|---|---|
| Preview | Free (built in) | Yes | No | Difficult | Yes |
| Adobe Acrobat | $15/month or $180/year | Yes | Yes | Yes | Yes |
| PDFpen | $80 one-time | Yes | Yes | Yes | Yes |
| Coherence X | $30 one-time | Yes | Yes | Yes | Yes |
| Web tools (Smallpdf, ILovePDF) | Free or $5–$10/month | Yes | Some | Yes | Yes |
Keeping your original file safe
When you save changes in Preview, it overwrites the original PDF by default. If you want to keep both the original and an edited version, duplicate the file first. Right-click the PDF in Finder, select "Duplicate", and you now have two copies. Open one in Preview, make your edits, and save — the original stays untouched.
This matters most when you are filling out forms or making significant changes. If you make a mistake and want to start over, you have the original to go back to. For small annotations like highlighting or adding a signature, overwriting is usually fine.
Frequently Asked Questions
Can I edit a PDF directly in Mail on Mac?
Yes. When you receive a PDF attachment in Mail, click it to open a preview. Click the markup toolbar icon (pen tip in a circle) and you can add text, signatures, and highlights. When you finish, Mail asks whether to save changes to the attachment. This is the same Preview editor, just opened from Mail instead of Finder.
What if Preview won't let me edit a PDF?
Some PDFs are locked or password-protected to prevent editing. Try opening the file in a different app like Adobe Acrobat Reader (free) to see if it offers an unlock option. If the PDF is genuinely locked by the creator, you need their password or permission to edit it.
Can I convert a scanned image of a document into editable text?
No, Preview cannot do this. You need optical character recognition (OCR) software. Adobe Acrobat has built-in OCR, as does PDFpen. Some free web tools like Smallpdf offer OCR, though the quality varies. OCR converts the image into text you can then edit.
Is it safe to upload my PDF to a free web editor?
Free web tools store your file on their servers while you edit it. If the PDF contains sensitive information like tax returns, medical records, or financial data, uploading it carries a privacy risk. Use Preview or a desktop app instead. If you do use a web tool, check their privacy policy and delete the file from their site when you finish.
How do I add a watermark or page numbers to a PDF?
Preview cannot add watermarks or page numbers. You need Adobe Acrobat, PDFpen, or Coherence X. These tools let you insert text or images on every page automatically. Web tools like Smallpdf also offer watermarking and page numbering features.