How to add your signature to any PDF for Free!

Are you digitally filling out a housing lease or work employment contract and need to sign your PDF and e-mail it? If you’re like me, you’re tired of having to deal with printing and mailing contracts. Here’s how to insert your signature on a PDF using completely free software.

1. Download the free GIMP software

GIMP stands for “GNU Image Manipulation Program”, and is similar to Photoshop. The user interface is not as nice but it doesn’t cost anything, works on multiple platforms, and performs most of the typical functions you would need.

2. Open the PDF contract with GIMP, choose 300 dpi for the resolution.

3. Sign a piece of blank paper in solid, dark ink (blue or black)

4. Take a picture of the signature (with your cell phone or digital camera)

5. Open the photo in GIMP

6. Adjust Color Levers (Colors -> Levels) to get rid of specks and imperfections, so the background is completely white and the signature is near completely black.

7. Choose Colors -> Threshold to get rid of any remaining imperfections

8. Choose Colors -> Color to Alpha to convert the white background to transparent

9. Choose Image -> Print Size and set the X and Y resolution to 300 dpi to match your contract document

10. Choose Image -> Scale Image and choose approx. 4 inches for the width to match the real-world width of your signature

11. Draw a box around the signature with the marquee tool and select Edit -> Copy.

12. Switch the window to your imported PDF and Edit -> Paste the signature.

13. Move and/or scale your signature around using the Move and Scale tool respectively to its final resting place.

14. File -> Export the image as a PNG

15. Now that you have a PNG you can import it in to an office program like Microsoft Word, LibreOffice, or Google Docs to then export the document as a PDF.