Advanced Mailto Encoder

Just found an awesome web tool and thought I would share it with everyone.

The tool is the Advanced Mailto Encoder and it attempts to stop email harvesting by spammers by obfuscating email addresses that need to be placed on web pages. The web site for the tool is hosted at and is absolutely loaded with email address encoding options.

I used the following settings for generating obfuscated mailto links for this site:

  • Step 1: Entered the email address to encode.
  • Step 2: Left all options empty.
  • Step 3: Selected the option to “Use HTML hex codes and URL encoded characters”. I left the letter encoding percentage the default, and set the HTML style value to 0%. For me, the HTML style value of 0% worked best otherwise my mailto links didn’t seem to render correctly in the browser when hovering over them. You can set the letter encoding percentage to any value you like.
  • Step 4: Selected the option to “Use HTML character encoding on some or all the letters”. I upped the value from the default, but you can set the letter encoding percentage to whatever value you desire.
  • Step 5: Left all options unselected.
  • Step 6: Clicked the “Encode Address” button and copied and paste the generated code into my web page.

As an example, the following HTML code is generated for the email address of when using the above settings:

<a href="mailto:us%65%72%40ho%73%74.%6e%61%6de">&#117;ser&#64;host&#46;n&#97;m&#101;</a>

And it renders as in the browser.

One caveat: The encoded address seems to have some extra semicolons that I had to manually remove, and I removed them in the above example. Not a huge deal, but something to be aware of.

I doubt this obfuscation will stop all email harvestors, but every little bit helps. Thanks Tyler Akins for making such a useful tool!


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