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How to add your signature to PDFs for free

Written By: James Rintamaki on August 30, 2009 54 Comments

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This post has been updated! Check out the new, easier, methods of adding your signatures to PDFs here

In an effort to go completely paperless, I was presented with the problem of needing to sign a document (pdf) that was emailed to me and then needing to send it back.  Without having to print out the form to sign it nor needing access to a scanner or fax machine to send it back, you can simply take a picture of your signature, and then using free tools you can “import” it “into” the PDF and email it right back! 

This may seem long and complicated at first, but once you read through it and do it once, it should be fast and easy a second time – And granted, there may be slightly easier ways to do this with paid tools, but this guide is for using freely available tools which you also may have one or two already installed!:

1. Download and install the tools

Here is what you need to download:

  • Adobe Reader 9 which you probably already have.  We will use this to view the original PDF and take a single screenshot to import into the image editing software (don’t worry, it will look good!),
  • Paint.net (or really, any drawing program that can do layers and make transparent images) which we’ll use to overlay your signature on the PDF screenshot, and then also to re-print to a new PDF,
  • CutePDF (or any other free PDF Printer), which as opposed to printing to a printer, will allow you to “print to” (create) a PDF, and
  • A way to get a copy of your signature on your computer.  I used my iPhone to take a picture of my signature, though, you can use what ever camera phone, real digital camera, etc that you have.

2. Convert your PDF to a screenshot (an image)

Open your PDF in Adobe Reader 9 and zoom all the way out so you can see the entire page (even if it looks small and you can no longer read anything):


Next, select the SnapShot tool (“Tools” –> “Select & Zoom” –> “Snapshot Tool”) and starting at one corner, click-and-drag to the opposite diagonal corner to highlight the entire page.  Once you do that, you should receive a dialog box saying that the selected area has been copied to the clipboard:


However, if you proceed in using what is currently copied, it will be exactly the same size as you are currently looking at it; meaning, it will be really small and will end up very pixilated when you “blow it up” to normal paper size when you re-print it as a PDF, such as the image below (click to enlarge to full size):


So, in order to fix this, make sure the page is still highlighted (transparent blue) and then zoom in quite a bit (“View” –> “Zoom” –> “Zoom To…”).  You don’t need to zoom to 5000%, but 200-300% should be enough.  While making sure it is still highlighted, right click anywhere it is blue-ish, and click “copy selected graphic”.  You now have a much larger screenshot of the PDF in your clipboard. 


Proceed by opening Paint.net and pasting into a new image (Edit –> Paste) and feel free to save this as a PNG file if you want (I’ll refer to this image as “pdf screenshot”).  Either way, to make things easier, go ahead and keep Paint.net open while we move forward.  You now have a large, high quality screenshot (image) of your PDF which is ready to have your signature placed on top of!


3. Get your signature onto your computer

Okay, so now you need to get your signature on the computer.  Chances are you have a decent enough camera phone (and a way to get those pictures onto your computer) that you can use to take a picture of your signature , such as the iPhone – or – you can of course use a scanner, a real digital camera, or however else you can come up with a way to do it.  With my iPhone, I just took a picture of the signature in a decently lit room and then emailed my self the picture:

get the signature signature_before

(and no, this is not my real signature, ha)

4. Prep your signature for overlaying on the PDF screenshot

We will now make the image black and white, enhance it (using brightness and contrast), and then make everything that is not the signature (the paper) to be transparent.  Open your signature in Paint.net (or whatever image software you are using) and 1) convert the image to black and white, and then 2) adjust the brightness and contrast so that it really is only black-and-white. 

To do this, start out by opening the signature image in Paint.net (“File –> “Open” –> find your image).  If you already have your pdf screenshot open, you should now be in a new Paint.net window:


First, we’ll go ahead and resize the signature just incase it is huge by going to “Image” –> “Resize”.  Make sure “Maintain aspect ratio” is checked and change the width to 1000 pixels (leave whatever number appears in the Height section as-is. It will probably not be the same as mine).  Click ok. (resizing now will help prevent issues when pasting it over the pdf screenshot later)


Now, 1) go to the “Adjustments” menu bar, then click “Black and White”, and then 2) go back to “Adjustments” and then “Brightness / Contrast” — for my particular image, I had to set brightness at 52 and contrast at 79 for it to look like the following (your settings will vary) – the goal here is to have the background as white as possible while having the signature stand out and be clear:


Now we need to make all the “white” become transparent so we can overlay it on top of the pdf screenshot.  

First, select the Magic Wand tool and start with a tolerance level of 50%:


Then, hold the CTRL key while you start clicking on the white areas of the image.  Keep clicking the white areas (while still holding CTRL) until they have all been selected so you get something that looks like this (zoom in if you need to in order to get enclosed small areas such as the white space in letters like P, B, O, etc):


At this point, you can then press the delete key, and everything that is highlighted (all the white) will be removed and will be replaced with transparency (white and grey checkered boxes):


There, now your signature is ready to be placed on the pdf screenshot!

5. Paste the signature onto the pdf screenshot

Start out by copying your entire signature by going to “Edit” –> “Select all” and then copy it (edit->copy).  Then, move on over to your pdf screenshot (just click on it’s thumbnail in the top-right corner if you still have it open, or if not, open it! [with Paint.net] ).

From here, create a new layer on top of your pdf screenshot by going to “Layers” –> “Add new layer”:  (this will allow you to place the signature “on top” of the pdf screenshot without covering anything up)


Next, paste the signature into this new layer (“Edit” –> “Paste).  Chances are, your signature will be a big large, but either way you will need to resize it to the size your actual signature would be and move it down to the signature line:


With the signature still selected (dotted lines still surrounding it), hold the SHIFT key on the keyboard while you click and drag one of the corners of the signature selection  (when you move the mouse cursor to one of the corners, the cursor should change from a solid black arrow to a white hand, thus signifying you can resize).  Hold the SHIFT key while you resize it so it will keep the same aspect ratio.   Continue to resize it until it is about the right size that you signature would be.  Once you are happy with the size, let go of the SHIFT key and release the mouse button – now, move the cursor to the middle of the signature so you now have a black arrow cursor – this will now allow you to move the signature down to the signature line:

black cursor

Now, click and drag the signature to the signature line and release the mouse button.  With the signature where you want it on the pdf screenshot, proceed to “flatten” the image (combine the “signature layer” with the “pdf screenshot” layer) by going to “Image” –> “Flatten”.   Congratulations, your PDF screenshot is now signed and ready to be re-saved (“printed”) as a pdf!

almost done

6.  Print to PDF

Now, go to “File” –> “Print”, and select your PDF printer (in my case, “CutePDF  Writer”).  Be sure that you select Full Page Photo and don’t choose the option for cropping if you see it (I am using Windows 7, but if you were using XP you may see the option for full page photo cropped) and continue to print.


Your PDF printer software will now most likely have some sort of dialog box asking you what to name, and where to save, your new pdf – go ahead with that, and then enjoy your signed pdf!


So there you have it, you were able to bypass having to print it and scan it in (or fax it)!  Have a simpler (free) way to add a signature to a PDF?  Did I miss a step you can’t seem to get passed?  Let me know in the comments!  (caveat emptor, this guide is in no way meant to act as a way to forge, or otherwise impersonate, someone’s signature!)

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54 Responses to “How to add your signature to PDFs for free”

  1. Tina on: 31 August 2009 at 9:53 pm

    Good Article, but for editing PDF, i prefer PDF editor more, it is quit easy to edit contents, security for PDF.

  2. Georgios on: 17 September 2009 at 7:14 pm

    hi there,

    thanks for the great article. it helped me a lot. i wish you would have mentioned at the end that you can safe the project, in case you wanna sign more documents later, and don’t want to keep paint.net open the whole time. other than that, GREAT HELP!!!

  3. Keshav Bhat on: 26 November 2009 at 11:56 am

    There is http://www.mylivesignature.com/ – it does not reflect ‘your’ signature but comes up with some interesting fonts that you can save

  4. Someone on: 20 February 2010 at 8:04 pm

    Dear James,

    Thank you so much ,

    Your explanation was so good and halpeful

    I hope i will get the oppurtunity to help others like you helped

    Me , i can promise you you did, more than you can imagine

    Thank you very much

    With best regards

    Someone you helped him

  5. mitchie on: 21 April 2010 at 10:14 pm

    too bad we can’t download it cause our free disk space is low… but i think i know it works because the proof are the comments.. good work!

  6. How can you add your signature to a PDF for free? | Consulting Rehab on: 26 April 2010 at 10:33 pm

    […] How To Add Your Signature to PDFs For Free […]

  7. Been Around on: 7 July 2010 at 11:58 am

    You can do the something without going through the hassle of editing it through paint by using Nitro PDF Reader. Has basically all the functions of Adobe Acrobat for free. Simply paste your jpeg signature to the document. Save. Done.

    • jdwotis on: 30 September 2011 at 9:05 am

      you can not do this with nitro free or paid it can not handle transparent images

    • Phillip on: 16 October 2011 at 9:51 pm

      Thank you. Been Around. The Nitro PDF Reader work very good, easy to copy from JPG and paste the signature.


  8. James Rintamaki on: 7 July 2010 at 12:22 pm

    @Been Around, but unfortunately Nitro is not free (well, it has a 14 day free trial) — can it handle transparent png’s?

  9. Been Around on: 7 July 2010 at 12:40 pm

    @James Rintamaki

    Nitro PDF Reader is indeed free (no trials involved). You need to download it from http://www.download.cnet.com as opposed from the Nitro website. For what its worth, its a beta version but works fine for me, 32 bit and 64 bit versions.

    Can handle .pdf, .bmp, .gif, .jpg, .jpeg, .tif, and .png files for sigs. I believe there is no need to create a transparent image as the software should do it for you. I just cropped a signature from another document and pasted it into Nitro and it works just fine.

  10. Len on: 28 July 2010 at 2:27 pm

    Was able to do this on mac with photostudio. My one issue is that my signature page is on page 16 of the document. How do you work in the first 15 pages?

  11. James Rintamaki on: 28 July 2010 at 2:34 pm

    @Been Around,

    Ah, that’s actually an even better/easier way to do this all — less tools to have to mess with, plus you can save (and password protect) you signature as a stamp within the program!


    Using my method, you could “print” the first 15 pages to a PDF, then “print” the last page with your signature on it also to a PDF, and just “append” that last page to the first PDF you created of the first 15 pages (by choosing to save the signed page as a pdf with same name as the 15 page pdf and selecting append as opposed to overwrite). OR, you could import your signature into Nitro PDF (linked by Been Around) above and just apply it to page 16 of the pdf and re-save it!

    • Mandi on: 27 April 2012 at 12:58 pm

      Thanks, very useful

  12. Len on: 28 July 2010 at 2:55 pm

    Will try. Does Nitro PDF work with MAC?

  13. James Rintamaki on: 28 July 2010 at 3:02 pm

    Ah, no, just Windows XP/Vista/7

  14. Kevin C on: 9 August 2010 at 5:39 pm

    James, this is one of the most helpful tutorials I have ever used. It saved me several bucks on faxing. Thank you!

  15. Anthony on: 23 November 2010 at 6:05 am

    This Is To Complicated Like You Said .
    Here Is My Way :)
    Get Foxit PDF Editor
    Open The File In Foxit PDF Editor The One You Want To Add The Image ( signature )
    At The Top of The Foxit PDF Editor Click Add Image From File( If You Need A signature Just Go To http://www.mylivesignature.com/ And Make One ..:) Save The Image ( signature ) And Use That.
    That’s It.

  16. qzzzvq on: 18 December 2010 at 2:18 pm

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  17. Marie Beyer on: 29 December 2010 at 5:48 pm

    Many thanks James, your explanations are very clear and most helpful. I was on the other side of the planet with my job contract sent to me to sign. Having no scanner, I nevertheless managed to send it back. Great help !

  18. Matthew on: 24 January 2011 at 4:39 pm

    Thanks for the great article.

    Once you create your signature image (PAINT.net rocks!) there is much easier (and free) way to apply it to the original PDF! (without having to bother with the screen-capturing or printing to image)

    Just get PDF-XChange Viewer (search for it), and then you can CTRL-V paste text or image directly into the document (unless it is encrypted/protected). You can also create a custom palette for the Stamp Tool with your signature image. Pretty awesome tool!

  19. Amanda on: 3 March 2011 at 8:51 am


  20. lauren on: 6 May 2011 at 9:10 am

    this was a big help and worked beautifully! thanks so very much!

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  22. Andrew on: 18 May 2011 at 12:29 pm