What are reliable methods to identify and prevent bots from submitting forms outside of double opt-in?
Summary
What email marketers say13Marketer opinions
Marketer from Email Geeks uses a layered approach for bot detection, starting at the network level and ending post-subscription with many steps in between.
Marketer from Email Geeks explains tracking mouse movement or xy coordinates where the button is clicked can help identify bots as they often lack the variety of real user interactions.
Email marketer from Security Forums shares using Javascript challenges to confirm a real users by requiring interaction to get the form, also using this to set a cookie to confirm a return user.
Marketer from Email Geeks warns against relying on a single bot detection method, as it would be easily bypassed.
Email marketer from Medium explains analyzing the speed of form completion can help identify bots, as they often fill out forms much faster than humans.
Email marketer from Auth0 shares that building in an anomaly detection system to identify unusual signup patterns can help with bot prevention.
Email marketer from Reddit says throttling form submissions to limit the frequency from single users over a time period is good at bot prevention.
Email marketer from Reddit suggests using IP address blacklisting, combined with monitoring failed login attempts and form submissions from the same IP, as a method to prevent bot submissions. Also using rate limiting.
Marketer from Email Geeks shares using Google reCAPTCHA v3 to get a score and using sitewide JavaScript to detect direct POST submissions are effective bot detection methods.
Email marketer from Stop Forum Spam says that using their database API is a good way to identify bad email addresses from form submissions.
Marketer from Email Geeks shares that there's no single way to detect bots; AWeber uses dozens of techniques and billions of data points to ID and filter out bots attempting to fill out user forms.
Email marketer from Stack Overflow shares that honeypot fields (hidden fields that bots fill out but humans don't) can effectively identify and prevent bot submissions.
Marketer from Email Geeks suggests using user-agent, IP, checking if the form is submitted with JavaScript, and blocking TOR IPs to catch almost all bots.
What the experts say4Expert opinions
Expert from Spam Resource shares limiting the number of submissions within a given time period from a specific IP address can effectively deter bots from mass submissions.
Expert from Email Geeks shares that reCAPTCHA and email verification are effective in handling most bot issues, but acknowledges that sophisticated attackers can bypass these measures.
Expert from Word to the Wise mentions analyzing form submission patterns, like unusual timing or inconsistent data, to identify and block bots.
Expert from Spam Resource explains the implementation of confirmation pages which is a good check to detect any automated form submissions.
What the documentation says3Technical articles
Documentation from OWASP explains that implementing CAPTCHAs, rate limiting, and input validation are crucial methods to prevent automated threats like bot submissions on web applications.
Documentation from Google Developers explains that reCAPTCHA v3 returns a score based on user interactions, allowing developers to identify suspicious behavior and prevent bot submissions by adjusting thresholds and implementing appropriate actions.
Documentation from Cloudflare explains that their bot management tools analyze request attributes (e.g., IP address, HTTP headers, and JavaScript fingerprints) to identify and mitigate bot traffic, protecting forms from automated submissions.