reCAPTCHA Email Address Protection Service

Recaptcha screenshot

reCAPTCHA Mailhide hides your email address from spammers with a captcha (puzzle) that makes twofold sense: meaningful words, and typing them helps digitize books.

Unfortunately, reCAPTCHA Mailhide is no longer available.

Fortunately, it has been replaced by reCaptcha v2 and v3, which are much easier to use.

What We Like
  • reCAPTCHA Mailhide protects your email address with a captcha, a small puzzle

  • Both visible and audible captchas make your email address accessible to most internet users

  • Accessible via an API, reCAPTCHA Mailhide lets your site create protected addresses on the fly

What We Don't Like
  • reCAPTCHA Mailhide lacks a nice way of setting default subjects or message bodies

  • The captcha, while bearable, is still a slight annoyance to the prospective sender

  • The audible puzzle is a tad difficult and cumbersome


  • reCAPTCHA Mailhide protects email addresses on the web from spammers' harvesting robots.
  • The full email address is only revealed after solving a captcha, a short puzzle easy for humans but hard for computers.
  • reCAPTCHA Mailhide puzzles are words scanned from books and help digitize the latter.
  • Using an API, you can create reCAPTCHA Mailhide protection for email addresses automatically on your site.
  • A PHP library makes it easy to do so on sites using that scripting language.

Review: reCAPTCHA Mailhide's Free Email Address Protection Service

Do you like captchas? (You know, the small puzzles that have you type distorted strings of disconnected characters when you sign up for something on the web or try to post a comment on a blog, for example.)

No — and yes, I guess, depending on the side from which you look at them. Captchas are an annoyance to solve, of course, and the annoyance level grows exponentially with their difficulty and frequency.

At the same time, captchas that protect your email address from being captured and exploited by spammers are a blessing — as long as they don't exasperate those trying to contact you too much.

This is where reCAPTCHA comes in with its Mailhide service. Instead of gobbledygook, reCAPTCHA has users type meaningful words. To make the puzzle-solving even more useful, the words come from books which have been scanned.

Text recognition programs recognize many a character and font, but humans are still a lot better. reCAPTCHA Mailhide's puzzles help correct the errors made in automatic digitization.

Now, reCAPTCHA Mailhide would be a great service even if its puzzles made less sense. Easy to use, reCAPTCHA Mailhide lets you create HTML code to protect your email address on the reCAPTCHA site, but you can also automatize the process. An API lets you — or your website rather — create reCAPTCHA Mailhide protection for email addresses, say in a blog's comments section, automatically.

reCAPTCHA Mailhide's simplicity comes at a minor price, of course: while you can add default subject and body text to your email address as you would in a regular mailto: link, reCAPTCHA Mailhide does always display the full address (including all encoded subject and body text).

In addition to its sensible visible captchas, reCAPTCHA Mailhide provides audible puzzles for more universal access. These, alas, make less sense and can be pretty difficult.