How to fill in a scanned PDF
A PDF created from a scan is often just a photograph of the page: it looks like a form, but it has no boxes you can type into. You can still complete it by placing text, ticks and a signature over the pages.
Updated 14 July 2026
Why you cannot type in the document
Native PDF forms can contain ready-made interactive fields. A scan, by contrast, normally contains a single image for each page. That is why the cursor does not enter the lines and the browser cannot detect any fillable fields.
You do not need to run OCR on the entire document just to enter a few details. An overlay editor keeps the original page intact and adds only the elements you need.
Step-by-step instructions
Always keep a copy of the original PDF, then work on a duplicate by following these steps.
- 01
Open the PDF
Choose the file on your device. CompilaPDF displays its pages in the browser without sending the document to a server.
- 02
Add the elements
Use Text for details, Tick or X for boxes, and Signature for a graphical signature.
- 03
Position everything accurately
Move each element onto the correct line and adjust its size and content. Zoom in if the scan is densely laid out.
- 04
Download and check
Export the new PDF, open it again and check every page before sending it.
If the scan is rotated, blurred or protected
The quality of the result also depends on the source document. Check these common issues before filling it in.
- A rotated or cropped page should be corrected at the source or with a dedicated tool before you fill it in.
- If the text is difficult to read, ask for a better scan: adding fields cannot recover information that has been lost.
- A password-protected or restricted PDF may not open or may prevent export.
- For very long documents, complete and check one section at a time to reduce mistakes.
Will the PDF not fill in with Adobe Acrobat Reader?
A scanned PDF does not automatically gain native fields in the Adobe Acrobat Reader app either: it remains an image of the page. Fill-in and annotation tools can place text and signatures over it, using a principle similar to the one described in this guide.
CompilaPDF is an independent, more focused option designed to work immediately in the browser without uploading the document. You do not need to install Adobe Acrobat software or create a CompilaPDF account.
Source: PDF features in Adobe Acrobat Reader.
Graphical signatures and validity
A signature drawn or imported in the editor is a graphical representation. It is not a digital or qualified electronic signature, contains no certificate and does not verify the signer's identity.
Check the recipient's instructions before sending the document. If the process requires a qualified electronic or digital signature, or reliable identification, use the service specifically provided for that purpose.
Adobe, Acrobat and Reader are trademarks or registered trademarks of Adobe in the United States and/or other countries. CompilaPDF is an independent service and is not authorised, sponsored or endorsed by Adobe.