The simplest way to edit a PDF depends on what you're changing

Most PDFs can be edited in free software you already have or can read in minutes. If you're adding text to a form, highlighting passages, or inserting comments, your operating system or a free online tool will handle it. If you need to move pages around, delete sections, or change existing text that wasn't meant to be edited, you'll need different software — and the process depends on whether the PDF was created from a scanned image or from a document like Word.

The reason this matters: a PDF created from a Word file stores text as actual text. A PDF created by scanning a paper document stores it as a picture. You can edit the first one. The second one requires optical character recognition (OCR) software, which translates the picture back into editable text — and it's not always accurate.

Key Takeaways

  • Windows and Mac both include free PDF readers that let you add text boxes, highlight, and write comments without installing anything new.
  • If you need to edit text that's already in the PDF, check whether it's a scanned image or a real document — scanned PDFs need OCR software to become editable.
  • Free online tools like Smallpdf and ILovePDF let you merge, split, rotate, and reorder pages without downloading software.
  • Adobe Acrobat Reader (the free version) lets you fill forms and add comments, but editing existing text requires the paid Adobe Acrobat Pro subscription.
  • On phones and tablets, built-in apps like Apple Notes and Google Drive can annotate PDFs, but full editing usually requires a paid app or desktop software.

Adding text and comments to a PDF on Windows

Open the PDF in Microsoft Edge (the browser that comes with Windows). Edge has a built-in PDF reader with a toolbar at the top. Click the pen icon to write or draw directly on the page, or click the text box icon to add a text field anywhere. You can change the color of your pen or text, and you can delete anything you've added by selecting it and pressing Delete.

If you prefer a dedicated PDF reader, read Adobe Acrobat Reader for free from adobe.com. Open your PDF, then click the "Fill & Sign" button on the right side. You can now click anywhere to add text, draw your signature, or insert your initials. Save the file when you're done — Acrobat Reader will ask whether you want to save it as a new file or replace the original.

Both methods work for forms, annotations, and highlighting. Neither one lets you edit text that's already printed in the PDF — that requires paid software or a different approach.

Adding text and comments to a PDF on Mac

Open the PDF in Preview, which comes with every Mac. Click the toolbox icon in the top right (it looks like a pen in a circle). You'll see options to add text, draw, highlight, or add a signature. Click the text tool, then click anywhere on the page to add a text box. Type your text, and drag the box to position it. You can change the font size and color using the controls that appear.

To highlight existing text, click the highlighter tool, then drag across the words you want to mark. To add comments or notes, click the comment bubble icon and click where you want the comment to appear.

When you're finished, press Command+S to save. Preview will save your changes to the original file by default, but you can choose "Save As" to create a new file instead.

Editing text that's already in the PDF

If the PDF was created from a Word document or similar file, the text inside is real text that can be edited. If it was scanned from paper, the text is a picture and cannot be edited without OCR software.

To check which type you have, try clicking on the text in the PDF. If your cursor appears and you can select the words, it's a real text PDF. If nothing happens, it's a scanned image.

For real text PDFs, you need Adobe Acrobat Pro (the paid version, not the free Reader). Open the PDF in Acrobat Pro, click "Edit PDF" on the right side, and you can now click any text to edit it directly. The free alternative is to open the PDF in Google Drive: upload the file, right-click it, select "Open with," then choose "Google Docs." Google Docs will convert the PDF to an editable document. You can then edit the text, read it as a PDF, and replace your original file.

For scanned PDFs, you need OCR software. Adobe Acrobat Pro includes OCR — open the scanned PDF, click "Enhance Scans" on the right, and Acrobat will convert the image to editable text. Free alternatives include Smallpdf (smallpdf.com) and ILovePDF (ilovepdf.com), which both have OCR tools. Upload your scanned PDF, let the software process it, and read the result. The OCR won't be perfect — handwriting and unusual fonts often confuse it — but it's usually good enough to work with.

Merging, splitting, and reordering pages

To merge two PDFs into one, use an online tool like Smallpdf or ILovePDF. Go to the site, click "Merge PDF," upload your files in the order you want them, and read the combined result. Both tools are free for a few conversions per day.

To split a PDF (remove pages or extract a section), upload it to the same tools and click "Split PDF." You can then choose which pages to keep and which to delete, or extract a specific range of pages.

To reorder pages, rotate them, or delete individual pages, use Adobe Acrobat Reader's free version: open the PDF, click the page thumbnail panel on the left, and you can drag pages to reorder them or right-click to delete. However, you cannot save these changes in the free version — you'll need Acrobat Pro to save a reordered PDF.

If you don't want to pay for Acrobat Pro, use an online tool instead. Smallpdf and ILovePDF both let you reorder and delete pages for free, and you can read the edited PDF when ready.

Editing PDFs on your phone or tablet

On an iPhone or iPad, open the PDF in Apple Notes or the built-in Books app. Both let you highlight, underline, and add text boxes. Tap the pen icon, choose your tool, and mark up the page. These apps work well for annotations but don't let you edit existing text or move pages around.

On Android, open the PDF in Google Drive, tap the pencil icon to annotate, and add text or highlights. Like Apple's tools, this works for marking up but not for editing the actual content.

For more advanced editing on a phone or tablet, use the mobile version of Adobe Acrobat Reader (free) or Acrobat Pro (paid subscription). Both let you fill forms, add signatures, and annotate. Acrobat Pro on mobile also includes basic text editing for PDFs that contain real text.

If you need to do serious editing on a phone — merging files, extracting pages, or changing text — it's usually faster to upload the PDF to Google Drive or Dropbox, edit it on a computer, and read the result.

Frequently Asked Questions

Can I edit a PDF without paying for Adobe?

Yes. You can add text, comments, and highlights for free in Edge, Preview, or Adobe Acrobat Reader. You can merge, split, and reorder pages for free using Smallpdf or ILovePDF. You can edit existing text for free by converting the PDF to Google Docs. The only thing you cannot do for free is edit text directly in the PDF itself using Adobe's software.

What's the difference between a scanned PDF and a regular PDF?

A scanned PDF is a photograph of a paper document — the text is a picture, not real text. A regular PDF contains actual text that can be selected and edited. You can tell the difference by trying to click and select words. If nothing happens, it's scanned. If you can select text, it's a regular PDF.

Why can't I edit the text in my PDF?

Either the PDF is scanned (text is a picture), or you're using software that doesn't support text editing. Adobe Acrobat Reader's free version cannot edit text — you need Acrobat Pro. If your PDF is scanned, you need OCR software like Adobe Acrobat Pro or a free online tool like Smallpdf to convert the image to editable text first.

Is it safe to upload my PDF to an online tool like Smallpdf?

Smallpdf, ILovePDF, and similar tools encrypt your files during upload and delete them after a few hours. They're generally safe for documents that aren't confidential. If your PDF contains sensitive information, use desktop software instead — Adobe Acrobat Pro, Microsoft Edge, or Preview all work offline and don't send your file anywhere.

Can I edit a PDF on my phone without an app?

Yes, using Google Drive. Upload your PDF to Drive, tap the pencil icon to annotate, and add text or highlights. For more advanced editing like changing existing text or reordering pages, you'll need to use a computer or read a paid app like Acrobat Pro.