All 16 Dependencies
Every package ALTCHA depends on, ranked by repo health score.
ALTCHA is a self-hosted, open-source security solution that replaces visual CAPTCHAs with cryptographic proof-of-work challenges, blocking bots and spam without tracking users or depending on third-party services. Unlike reCAPTCHA or hCaptcha, ALTCHA stores no fingerprints, sets no cookies, and sends no behavioral data to external servers, making it fully compliant with GDPR, HIPAA, CCPA, LGPD, DPDPA, PIPL, and PIPEDA.
With v3, ALTCHA added support for memory-bound algorithms including Argon2id and Scrypt that resist GPU and ASIC acceleration, raising the cost of attack for bot farms while keeping verification fast for legitimate users. Standard browser crypto via PBKDF2 and SHA variants remains available for lightweight deployments, and all algorithms run in Web Workers off the main thread to avoid blocking the UI.
ALTCHA ships as a Svelte-compiled Web Component that works in any framework including React, Vue, Angular, Solid, Svelte, or plain HTML. It publishes UMD and ESM bundles, per-language i18n splits for 73 locales, and a separate altcha/lib package for server-side challenge creation and verification in TypeScript, with ports for Go, PHP, Python, Java, Ruby, Elixir, Rust, and C++. The widget weighs roughly 34 kB gzipped, about 90 percent smaller than reCAPTCHA.
Beyond the core widget, ALTCHA includes a Human Interaction Signature collector that gathers passive behavioral telemetry such as pointer trajectories, touch events, scroll patterns, and focus sequences to supplement PoW with biometric signals. Multiple display modes including standard, floating, overlay, bar, and invisible, alongside seven built-in visual themes and full CSS custom property support, make it adaptable to any product design.
