Software Alternatives & Startups

SharkEyes.dev VS ALTCHA

Compare SharkEyes.dev VS ALTCHA and see what are their differences

SharkEyes.dev

Protect your website forms from spam and fake signups without annoying captchas. Privacy-first security with zero fingerprinting. Try it now.

SharkEyes.dev screenshot
Rating
0 reviews
Pricing
Freemium $9 / Monthly (Pro Plan, 30 domains, Advanced features, Priority support)
ALTCHA

ALTCHA is a free CAPTCHA alternative that uses a proof-of-work mechanism to protect your website, and online services from spam.

ALTCHA Simple, user-friendly verification.
Rating
0 reviews
Pricing
Open source Free

Which is more popular?

Based on our record, ALTCHA seems to be more popular. It has been mentioned 3 times since March 2021.

social mentions
0 vs 3
Web App popularity
100% vs 0%
alternatives listed
6 vs 81

Base details

Website, pricing, platforms and company facts side by side.

SharkEyes.dev
ALTCHA
Website sharkeyes.dev altcha.org
Pricing
Freemium $9 / Monthly (Pro Plan, 30 domains, Advanced features, Priority support) Official pricing
Open source Free
Platforms
Web REST API
Company Startup from Israel · 1 - 9 employees · 2025
Listed in

About SharkEyes.dev and ALTCHA

In their own words, as submitted to SaaSHub.

SharkEyes.dev
ALTCHA

Tired of spam bots attacking your website forms? Fake registrations, junk inquiries, and comment spam standard CAPTCHAs dont help. They only frustrate real users while "smart" bots bypass them anyway. SharkEyes takes a different approach. The system quietly detects spam and fake registrations in...

Read more about SharkEyes.dev

ALTCHA uses a proof-of-work mechanism to protect your website, APIs, and online services from spam and unwanted content. Unlike other solutions, ALTCHA is free, open-source and self-hosted, without external services, does not use cookies nor fingerprinting, does not track users, and is fully...

Read more about ALTCHA

Features and specs

What each product offers, as listed by its team.

SharkEyes.dev 4 features
ALTCHA 9 features
  • Privacy
    Prioritizes user privacy by default. SharkEyes does not harvest, store, or sell user telemetry data to third parties.
  • Security
    Protects web forms-including login, registration, contact, and comment sections-from automated spam, brute-force attacks, and bad bots using behavioral scoring.
  • Granular Control & Dashboard
    Includes an intuitive dashboard to set security rules, manage allowed domains, and toggle protection modes instantly.
  • Developer-Friendly
    Built for simple deployment with clean REST APIs, lightweight SDKs, and transparent configuration without complex infrastructure overhead.
  • Privacy-friendly, GDPR compliant
    No cookies, no tracking, no external servers.
  • Frustration-free
    No visual puzzles. PoW Captcha is better for people.
  • Spam Filtering
    Employs machine learning to categorize submitted data and identify unwanted messages.
  • Open-source
    Free to use, free to modify. MIT licensed.
  • End-to-End Encryption
    The Encryption Shield mitigates data breaches by encrypting data with asymmetric end-to-end encryption.
  • Digital e-Signatures
    e-Signatures made easy with eIDAS-compliant simple and advanced signatures - qualified digital certificates and DigiDoc.
  • Visual Form Builder
    Create custom forms effortlessly with the visual form builder, empowering users to design tailored solutions without any coding expertise.
  • File Attachments
    Safely request and securely store file attachments with end-to-end encryption, ensuring the utmost protection for your data.
  • Send to Email or Webhook
    Configure forms to seamlessly send data to email, APIs, or webhooks using processors, facilitating efficient data handling and integration with your workflows.

Category popularity

How often each product is chosen within a category, 0–100% relative to the other.

Score bands 0–20 21–40 41–50 51–60 61–100
SharkEyes.dev
ALTCHA
100% 100%
0% 0%
0% 0%
100% 100%
100% 100%
0% 0%
0% 0%
100% 100%

Questions & Answers

As answered by people managing SharkEyes.dev and ALTCHA.

What makes your product unique?

SharkEyes.dev's answer

SharkEyes delivers privacy first spam and bot protection without annoying captchas or invasive browser fingerprinting. It blocks automated submissions seamlessly in the background, ensuring a frictionless user experience while fully

ALTCHA's answer:

What makes ALTCHA unique is that it is free, open-source and self-hosted, without external services, does not use cookies nor fingerprinting, does not track users, and is fully compliant with GDPR. Unlike other captcha solutions, ALTCHA does not require users to solve puzzles or captchas and uses a proof-of-work mechanism instead.

Why should a person choose your product over its competitors?

SharkEyes.dev's answer

Traditional captchas ruin user experience and lower conversion rates, while big security vendors often track user data across the web. SharkEyes balances high-grade security with complete user privacy and zero user friction, making it quick to deploy, affordable for growing businesses.

ALTCHA's answer:

Here are some key reasons why a person should choose ALTCHA over its competitors:

  • Privacy compliance - ALTCHA is fully compliant with privacy regulations like GDPR since it does not use cookies, fingerprinting or track users. This is a major advantage over other captcha solutions.
  • Open source and self-hosted - ALTCHA is free, open source software that can be self-hosted without relying on external services. This gives more control and independence to the user.
  • Accessible design - ALTCHA uses a proof-of-work mechanism instead of puzzles or captchas, making it more friendly and accessible for humans. Captchas can be difficult for some users.
  • Machine compatibility - ALTCHA is designed to also work for machines and APIs, making services accessible for bots and automated systems. Other solutions may not be as compatible.
  • Modern approach - ALTCHA represents a privacy-first, inclusive approach to spam protection as opposed to traditional captcha methods. This future-proofs the solution.
  • Effective spam filtering - In addition to proof-of-work, ALTCHA also offers an effective spam filter module to block sophisticated spam attacks. This provides comprehensive protection.

So in summary, ALTCHA's privacy compliance, open design, accessibility, machine compatibility and modern approach give it clear advantages over competing captcha solutions.

Which are the primary technologies used for building your product?

SharkEyes.dev's answer

JavaScript, Golang, Python, REST API, Webhooks, Cloud Infrastructure, Bash, and Lightweight Anomaly Detection Algorithms.

ALTCHA's answer:

JavaScript and Svelte.

How would you describe the primary audience of your product?

SharkEyes.dev's answer

Web developers, SaaS founders, indie hackers, and digital agencies looking for an easy-to-integrate, privacy-centric alternative to reCAPTCHA or hCaptcha for protecting lead forms, signups, and feedback channels.

ALTCHA's answer:

Our primary audience for ALTCHA Forms includes enterprises, medium and small businesses, non-profits, and individuals who need a reliable, secure, and compliant solution for data collection and management. Whether you're a large corporation dealing with extensive regulatory requirements, a small business looking to protect customer and employee data, a non-profit organization managing sensitive information, or an individual seeking robust data security, ALTCHA Forms provides the tools and features necessary to meet your needs. With a focus on compliance, user-friendly design, and advanced security measures, our platform is tailored to support diverse users in navigating complex regulatory landscapes and ensuring data protection.

What's the story behind your product?

SharkEyes.dev's answer

SharkEyes was created out of frustration with complex, user-unfriendly captchas that hurt site conversions and compromise visitor privacy. We wanted a lightweight, modern security solution that protects forms effectively without forcing real users to solve puzzles or giving away their personal browsing data.

User comments

Share your experience with using SharkEyes.dev and ALTCHA. For example, how are they different and which one is better?

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Social recommendations and mentions

Recommendations tracked on public social media and blogs since March 2021.

SharkEyes.dev 0 mentions
ALTCHA 3 mentions

Tracking SharkEyes.dev since Sep 2026.

  • A self-hosted Google reCAPTCHA alternative (we ship it)
    The captcha on orkestr is Altcha. Self-hosted, no third-party JS, no Google, no behavioral tracking. Users don't see a puzzle. There's a single checkbox and a quiet "verifying..." while the browser does some math. About a second, total. - Source: dev.to / 4 months ago
  • Why Proof-of-Work Beats CAPTCHA for Form Protection
    Here's how PoW works for form protection (using the ALTCHA wire format):. - Source: dev.to / 6 months ago
  • Wicketkeeper – privacy-friendly, self-hostable PoW CAPTCHA
    Go based, similar to JS based ALTCHA https://altcha.org/ discussed at https://news.ycombinator.com/item?id=43971068. - Source: Hacker News / 9 months ago

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