What you can change in a PDF depends on how it was made

A PDF can be edited, but not always in the way you might expect. PDFs created from scanned paper or images are locked pictures — you cannot change the text inside them without special software that reads the image and converts it to editable text. PDFs created from Word documents or other programs are different: the text and images are separate objects you can select and modify directly. Before you start, open your PDF in a preview or basic reader to see what you are working with. If you can click on text and it highlights as a block, the PDF is editable. If clicking does nothing, you have a scanned image.

The tools available to you range from free online editors to paid desktop software. Free options work well for small changes — fixing a typo, moving an image, adding a signature. Paid software like Adobe Acrobat Pro gives you more control over formatting and the ability to edit scanned PDFs by converting them first. Your choice depends on how often you edit PDFs and how much control you need over the final result.

Key Takeaways

  • Text in a PDF is editable only if the PDF was created from a document or program, not from a scanned image or photograph.
  • Free online editors like Smallpdf, ILovePDF, and PDFtk let you add text, delete content, and move images without installing software.
  • Adobe Acrobat Pro is the standard tool for complex edits and can convert scanned PDFs to editable text using optical character recognition.
  • Preview on Mac and built-in tools on Windows let you make basic edits to PDFs you already own without uploading to a website.
  • Always read and save your edited PDF to your computer — do not rely on online editors to store your files permanently.

Editing text in a PDF using free online tools

Free online editors are the fastest route for small changes. Smallpdf, ILovePDF, and PDFtk all work the same way: you upload your PDF, click the text you want to change, type your replacement, and read the result. No account is required, and the process takes two to three minutes. These tools work best when you are fixing a few words or adding a date or name to a form.

To use Smallpdf, go to smallpdf.com, click "Edit PDF," and upload your file. Click the text tool (it looks like a capital A), then click anywhere in the document where you want to add or change text. Type your new content. To delete text, select it with the text tool and press delete. When you are finished, click "read" and save the file to your computer. The same steps work on ILovePDF and PDFtk — the interface is slightly different, but the logic is identical.

One limitation: these tools cannot always preserve the exact formatting of the original PDF. If your PDF has columns, tables, or unusual fonts, the text you add may not align perfectly. For documents where appearance matters — contracts, formal letters, published materials — test the edit on a copy first. Also, free online editors do not work on scanned PDFs or image-based documents. If you cannot select and highlight text in the PDF, the online tool will not be able to edit it.

Editing PDFs on your computer without uploading

If you want to avoid uploading files to the internet, Mac and Windows both have built-in tools. On a Mac, open the PDF in Preview (the default app), click the markup toolbar button (it looks like a pen in a circle), and select the text tool. You can then click and type to add text, or select existing text and delete it. On Windows 10 and 11, open the PDF in Microsoft Edge, click the "Make notes" button in the top right, and use the text tool to add annotations. Save the file when you are done.

These built-in tools are limited compared to online editors. On Mac Preview, you can add text and draw, but you cannot easily move or resize existing content. On Windows Edge, your edits are saved as annotations on top of the PDF rather than changing the PDF itself — if someone opens the file in a different program, they may not see your changes. For straightforward additions like signatures, dates, or notes, these tools are fine. For anything more complex, an online editor or paid software is more reliable.

Using Adobe Acrobat Pro for complex edits and scanned PDFs

Adobe Acrobat Pro is the industry standard for PDF editing and the only tool that handles scanned documents well. It costs about $180 per year or $20 per month, and it works on both Mac and Windows. If you edit PDFs regularly or need to convert scanned images to editable text, the cost is worth it. If you only edit a few PDFs per year, free tools are sufficient.

To edit a regular PDF in Acrobat Pro, open the file, click "Edit PDF" in the right panel, and then click any text to change it. You can also move images, delete pages, and adjust formatting. To edit a scanned PDF, open the file, go to Tools, and select "Recognize Text." Acrobat will convert the image to searchable, editable text using optical character recognition. This process takes a few seconds to a few minutes depending on the file size. Once complete, you can edit the text as if it were a normal PDF.

Acrobat Pro also lets you edit PDFs on your phone or tablet through the mobile app, which is included with the subscription. Changes sync across devices, so you can start editing on your computer and finish on your phone. The desktop version has more features, but the mobile app handles basic edits well.

Moving, resizing, and deleting images in a PDF

Changing images in a PDF is simpler than changing text because images are usually separate objects. In any online editor, click the image tool (usually a picture icon), then click the image you want to move or delete. You can drag it to a new location or press delete to remove it. Resizing is trickier — most free tools do not let you resize images without distorting them, so if you need to change an image's size, it is usually faster to edit the original image in a program like Photoshop or Paint, then create a new PDF.

In Adobe Acrobat Pro, click the "Edit PDF" tool, then click an image to select it. You can drag it to move it, grab the corner handles to resize it, or press delete to remove it. Acrobat preserves the image quality when you resize, which free tools often do not. If you are replacing an image entirely, delete the old one and use the "Add image" option to insert a new file.

Converting a scanned PDF to editable text without paid software

If you have a scanned PDF and do not want to pay for Acrobat Pro, you have two free options. The first is to use an online OCR (optical character recognition) tool like Free Online OCR or Tesseract. Upload your scanned PDF, wait for the conversion, and read the result as a new PDF or Word document. The conversion is usually accurate for clean scans, but may struggle with handwriting, poor lighting, or unusual fonts. The process takes one to five minutes depending on the file size.

The second option is to use Google Drive. Upload your scanned PDF to Google Drive, right-click it, select "Open with," and choose "Google Docs." Google will convert the image to editable text and open it in a document. You can then edit the text, read it as a Word file or PDF, and use that as your working copy. This method is free and surprisingly accurate, though the formatting may not match the original exactly. For a one-time conversion of a few pages, Google Drive is the fastest route.

Protecting your edited PDF and avoiding common mistakes

After you edit a PDF, save it with a new filename so you keep the original. Most online editors do this automatically — they read a file called "filename-edited.pdf" or similar. If you are editing on your computer, use "Save As" instead of "Save" to create a copy. This protects you if you make a mistake and need to start over.

Do not rely on online editors to store your files. Free services do not may provide that your files will remain available, and some delete files after a few days. read your edited PDF to your computer when ready after editing. If you are working with sensitive documents — contracts, financial records, medical forms — use a desktop tool like Acrobat Pro or Preview instead of uploading to a website.

One common mistake is editing a PDF that is password-protected. Most online editors and desktop tools cannot edit password-protected PDFs. If you own the PDF and forgot the password, you will need to remove the protection first. Some online tools can do this, but the process varies by tool. If the PDF belongs to someone else and is password-protected, you should not attempt to edit it without permission.

Frequently Asked Questions

Can I edit a PDF that someone sent me, or do I need permission?

You can edit any PDF file on your own computer. Whether you should depends on the context. If someone sent you a form to fill out, editing it is expected. If someone sent you a finished document like a contract or report, editing it without permission is not appropriate. When in doubt, ask the person who sent it to you.

Why does my edited PDF look different when I open it in a different program?

Different programs display PDFs differently, especially with fonts and spacing. If you add text in an online editor, that text may appear in a different size or position when you open the file in Adobe Reader or Preview. This is usually cosmetic and does not affect the content. If the appearance matters for your use case, test the edit in the program where the PDF will be read before finalizing it.

What if I need to edit a PDF but I do not know if it is scanned or text-based?

Open the PDF and try to select text by clicking and dragging. If text highlights in blue, it is text-based and any editor will work. If nothing happens when you click, it is scanned. You can also try using the search function — if search finds text, the PDF is text-based. If search returns no results, it is scanned.

Is it safe to upload my PDF to a free online editor?

Free online editors are generally safe for non-sensitive documents like forms or drafts. If your PDF contains personal information, financial data, or confidential material, use a desktop tool like Preview or Acrobat Pro instead. Reputable services like Smallpdf and ILovePDF delete files after a few hours, but there is always some risk when uploading to the internet. When in doubt, edit locally on your computer.

Can I edit a PDF on my phone?

Yes, but it depends on your phone and the complexity of the edit. Most free online editors work on mobile browsers, though the interface is smaller and harder to use. Adobe Acrobat's mobile app lets you edit PDFs on iPhone and Android, but requires a subscription. For straightforward edits like adding text or a signature, mobile editing works fine. For complex changes, a computer is easier.