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How to edit text in a PDF, and why it is harder than in Word

Change words, fix typos, fill in forms and add text to a PDF in your browser. Why PDFs are hard to edit, how fonts are matched and what to do with scanned PDFs.

PDF2 min readUpdated

Key takeaways

  • A PDF stores text as positioned characters, not flowing paragraphs, so edits work best line by line.
  • Many PDFs embed only the letters they use; a good editor matches the look with a similar font when needed.
  • Scanned PDFs are pictures of text: run OCR first, or cover and replace the text.
  • Editing a digitally signed PDF invalidates the signature. Never alter official documents to mislead.
On this page
  1. Why PDFs are not like Word documents
  2. Editing existing text
  3. Adding text, filling forms and signing
  4. Scanned PDFs
  5. Find and replace
  6. Signed and official documents

Why PDFs are not like Word documents

PDF, standardised as ISO 32000, was designed to make a page look identical everywhere, not to be edited. Inside the file, text is a series of instructions such as "draw these characters in this font at this position". There are no paragraphs that reflow: if you make a sentence longer, the text after it does not move along. Fonts are often subset, meaning only the letters actually used are embedded, so a letter that never appeared in the original may not exist in the file.

Editing existing text

  1. Open the PDF in Edit PDF.
  2. Choose the text tool and click the line you want to change.
  3. Type your correction. The editor matches the font family, size, weight, style and colour, and covers the old text with the page's background colour.
  4. Download the edited file.

Short corrections, such as a name, date, amount or typo, give the best results. For long rewrites, it is usually quicker to edit the original Word or design file and export a new PDF.

Adding text, filling forms and signing

  • Add text anywhere on the page, for example on a form without fillable fields.
  • Fillable forms are detected automatically; type in the boxes, then flatten the form if you do not want answers changed later.
  • Sign by drawing, typing or uploading your signature, or use Sign PDF for signing only.

Scanned PDFs

If you cannot select any text in the PDF, each page is a photo. You have two options: cover the old words with a white box and type new text on top, or extract the text with image to text (OCR) and rebuild the document.

Find and replace

To change the same word throughout, such as a company name or a year, use find and replace. Check every page afterwards: a replacement longer than the original may need a slightly smaller font to fit.

Signed and official documents

  • Any change to a PDF with a digital signature breaks that signature, and PDF readers will show it as invalid. Ask the sender for a corrected copy instead.
  • Altering certificates, bank statements, invoices, IDs or other official documents to deceive someone is fraud in almost every country. Edit only documents you own or are authorised to change.

Sources

  1. ISO 32000-2:2020, Document management: Portable document formatiso.org
Written by the Toolkeel team at Sole Digital Media

Fact-checked against the sources above. We test every tool we mention. Editorial policy.

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