GeeTest v3 vs v4: Differences in Initialization, Parameters, Secondary Validation, and Automation Integration Architecture
GeeTest v3 and v4 are two independent architectures: v3 requires server-generated dynamic challenge, client initialization with gt and challenge, and returns validate and seccode; v4 removes request stickiness, uses static captcha_id, introduces adaptive verification, and returns lot_number, pass_token, captcha_output, and gen_time, with server-side HMAC-SHA256 validation.
reCAPTCHA v2 vs v3: Interaction, Backend Verification, and Automation Handling
reCAPTCHA v2 requires user interaction and returns only pass or fail; v3 is unobtrusive and returns a 0.0–1.0 risk score plus an action label, with your backend deciding whether to allow. This article compares the two in terms of frontend behavior, siteverify responses, token rules, selection, hybrid solutions, and automation handling, and lists common pitfalls during implementation.
