I couldn't get it working. Base64 is accepted at the time of creating signature & the image also displays in compose window, but recipient of email do not see any image.

gmail_signature But it will be helpful as currently images in Gmail Signature can be only referred by URLs. So base64 image format is an option but not sure if its supported.

  • i would yell at gmail for showing such garbage at the end of my mails .. thus: i doubt that it will work (too much client-diversification to be reliable)
    – akira
    Jan 24, 2012 at 12:24
  • @akira You don't get any "garbage" in your email. The picture in the original post above is of the base64 code but the html rendering engines in the browsers and email clients will display it as the image that it represents.
    – bgmCoder
    Oct 7, 2015 at 2:20
  • i am refereing to the decoded stuff (aka the "image") as "garbage".
    – akira
    Oct 15, 2015 at 9:05

3 Answers 3


You can add HTML to Gmail by using a simple trick.

  • Write something into the signature part. Lets say you write "changeme"
  • then inspect that element
  • then click the whole <div>changeme</div>
  • right click
  • edit as HTML
  • paste your code
  • inspect something else.
  • Change a letter into your signature with something else and replace it back so Google can detect that you changed the signature.
  • Save


  • Not a reliable option as Gmail has a limit on maximum signature size. Adding 9KB base64 encoded image failed due to final signature size going beyond the limit.
    – IvanR
    Aug 1, 2018 at 12:55
  • This didn't work as it is as of today, at least in Firefox.
    – RafaelLVX
    May 3, 2019 at 20:01
  • I tried today on Firefox 66.0.4. I managed to add HTML to my signature by following the exact steps above. However, the 'src' attribute of my (inline base64) image was stripped off of my signature. The rest was apparently left as-is and in a working state, but gmail seems to specifically target inline images and remove them.
    – NicolasB
    May 9, 2019 at 15:09

What you are asking for is clearly not-at-all possible and not-at-all constructive for GMail at all.

You can manually add an image at the end of the message though.

  • 1
    I don't agree with "not constructive". You can use base64 within html and you end up with the image being embedded in the code rather than existing as a file. You can use base64 in emails within regular email clients. However, I agree that it seems you can't do it in gmail because there is no way to insert html directly (or doesn't seem to be; I actually came here looking for a way to do just this).
    – bgmCoder
    Oct 7, 2015 at 2:18

Yes, easy (and no, probably not):

You can make an html page (which contains your Base 64 Code), load it in your browser, copy and paste it (once rendered by your browser) and then paste that into the GMail signature box.

The difficulty is that most images (in Base 64) will exceed the max length of txt / html code that Google's database will allow to be stored as a footer.

So Yes and No. Yes technically, but no because it is unlikely that your image will be small enough to stay within the max character length allowed in a footer. If you are talking about icons? Yes, no prob. A full size photo? Impossible.

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