How to Edit a PDF Online for Free

Before you start: what kind of edit do you need?

“Editing a PDF” can mean very different things. It helps to decide which one you need before you open the file:

• Adding information — typing into a form, writing a note, adding a date or a signature. SmartPDF is designed for this.
• Marking up — highlighting passages, circling mistakes, drawing arrows or boxes for review. SmartPDF handles this too.
• Changing existing text — fixing a date, name, price or typo. SmartPDF’s Edit text tool does this one line at a time. Rewriting whole paragraphs so the text reflows isn’t possible in a PDF; for that, change the original document (Word, Google Docs, etc.) and export a new PDF.
• Removing confidential information — this is redaction and needs a dedicated redaction tool that deletes the underlying content. Covering text with a shape does not remove it.

Step-by-step: edit a PDF in your browser

1. Open the editor. Go to the SmartPDF editor and drag your PDF onto the drop zone, or press Open PDF Editor and choose the file. It opens in the same tab; nothing is uploaded.
2. Find the right page. Scroll through the document, click a page thumbnail on the left (on phones, tap the pages button), or type a page number in the bar at the bottom. Use the zoom buttons or Fit to width to get a comfortable size.
3. Choose a tool. The toolbar has Text, Highlight, Draw, Erase, Box, Ellipse, Line, Arrow, Image and Sign. The settings panel shows options for the active tool, such as color or font size.
4. Place your edits. Click, tap or drag on the page. Switch to the Select tool to move items, resize them with the corner handles, or change their settings.
5. Fix mistakes. Press Undo (Ctrl+Z, or ⌘Z on a Mac) to step back, and Redo to step forward again. The Erase tool removes anything you added with a click — it never touches the original page content.
6. Download. Press Download Edited PDF, confirm the file name, and save the new file. Your original PDF stays unchanged on your device.

Choosing the right tool

Edit text

Click any line of the document’s own text to change or delete it. The line opens with its current wording; type the correction and click outside it. SmartPDF covers the old line with the page background color, writes your text in the same place with the same size, weight, italics and color, using a metric-compatible version of the original font. The old words still exist in the file underneath, so don’t use it to hide sensitive details. On a scanned page, press Recognize text first: SmartPDF reads the page with OCR in your browser and then every line becomes editable.

Add text

Best for filling in forms that don’t have fillable fields, adding dates, names and short notes. You can change the font, size, color, weight and alignment. See how to add text to a PDF.

Highlight

Marks an area with translucent color. Because it highlights a rectangle rather than individual characters, it works on any page — including scanned ones. More in how to highlight a PDF.

Draw, shapes and arrows

Use the pen for handwriting or quick circles, and shapes and arrows for clean review marks. Every shape can be recolored, resized or moved after you draw it.

Image and signature

Insert a logo, stamp or photo as PNG, JPEG or WebP. To sign, draw your signature and place it on the line; see how to sign a PDF.

Editing a PDF on a phone or tablet

On small screens the tools move to a bar at the bottom. Drawing tools take over one-finger gestures so you can draw without the page scrolling; switch back to Select to scroll normally. The settings panel opens from the Settings button. For long documents, use the page list to jump straight to the page you need.

Troubleshooting

• “This PDF is password-protected.” Protected files can’t be edited here. Open it in software that knows the password, remove the protection if you’re allowed to, and try again.
• The file opens slowly. Very large or image-heavy PDFs need a lot of memory. Close other tabs or use a computer instead of a phone.
• The document was digitally signed. Any change invalidates an existing digital signature. Ask the sender for an unsigned copy if you need to edit it.