I built FriendlyCaptcha over the past 2 months because I was tired of there being no good alternatives to Google's ReCAPTCHA and the like that your users won't hate you for.
FriendlyCaptcha is based on proof-of-work (think hashcash): instead the user labeling fire hydrants in images, they commit their device to doing computations for at least a couple of seconds. The idea is that the cost of an attack is not so different for a spammer: instead of running a ML model to label the images (or solve the audio challenge) they would need to solve the proof-of-work challenge. That's probably good enough for most if not all websites, and compares favorably against ReCAPTCHA which has many issues (privacy, accessibility, bundle size & bandwidth, menial tasks, customizability, closed-source).
The attacker shouldn't be able to use much more optimized code, which is where WebAssembly comes in: the FriendlyCaptcha solver is WASM based (with JS fallback) which achieves close to native speeds. The solver [0] and widget [1] are all open source so you can play with it or customize it for your website.
In case you missed it on the main website, there is a demo here [2].
FriendlyCaptcha is based on proof-of-work (think hashcash): instead the user labeling fire hydrants in images, they commit their device to doing computations for at least a couple of seconds. The idea is that the cost of an attack is not so different for a spammer: instead of running a ML model to label the images (or solve the audio challenge) they would need to solve the proof-of-work challenge. That's probably good enough for most if not all websites, and compares favorably against ReCAPTCHA which has many issues (privacy, accessibility, bundle size & bandwidth, menial tasks, customizability, closed-source).
The attacker shouldn't be able to use much more optimized code, which is where WebAssembly comes in: the FriendlyCaptcha solver is WASM based (with JS fallback) which achieves close to native speeds. The solver [0] and widget [1] are all open source so you can play with it or customize it for your website.
In case you missed it on the main website, there is a demo here [2].
[0]: https://github.com/gzuidhof/friendly-pow
[1]: https://github.com/gzuidhof/friendly-challenge
[2]: https://friendlycaptcha.com/demo