
reCAPTCHA
hCaptcha
Cloudflare Turnstile
Akismet
Private Captcha
mosparo
Cap Captcha
ALTCHA is a free CAPTCHA alternative that uses a proof-of-work mechanism to protect your website, and online services from spam.

Waitlister.me
LaunchList
WaitlistMaster is waitlist software for pre-launch products. Create a branded waitlist page, collect emails, and grow through built-in referrals — signups move up the queue by inviting others. Includes conversion analytics, top-referrer tracking, CSV

Which is more popular?
Based on our record, ALTCHA seems to be more popular. It has been mentioned 4 times since March 2021.
Website, pricing, platforms and company facts side by side.
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|---|---|---|
| Website | altcha.org | waitlistmaster.com |
| Pricing | ||
| Platforms | — | |
| Company | — | 1 - 9 employees · 2026 |
| Listed in |
In their own words, as submitted to SaaSHub.


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...
Launch a branded waitlist page in minutes. Signups move up the queue by referring friends, so your list grows itself. Track top referrers and conversions, export anytime, connect your own domain. Free for 300 leads — $79/mo handles a million.
What each product offers, as listed by its team.


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


As answered by people managing ALTCHA and WaitlistMaster.
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.
WaitlistMaster's answer:
Most waitlist tools make you choose: a good-looking landing page, or a referral engine. Getting both usually means running two products and gluing them together with Zapier.
WaitlistMaster ships both as one thing. Every signup automatically gets a referral link and a visible queue position, so inviting others moves them up — the viral loop is the default behavior, not a feature you configure.
The second difference is pricing that doesn’t punish a launch that works. Most tools in this category charge per subscriber and escalate sharply as your list grows, which means the better your launch goes, the more it costs you at exactly the moment you have no revenue. WaitlistMaster is $79/month for up to a million confirmed leads, flat. A waitlist that goes viral costs the same as one that doesn’t.
ALTCHA's answer
Here are some key reasons why a person should choose ALTCHA over its competitors:
So in summary, ALTCHA's privacy compliance, open design, accessibility, machine compatibility and modern approach give it clear advantages over competing captcha solutions.
WaitlistMaster's answer:
Over other pre-launch tools: the free tier is genuinely usable — 300 confirmed leads, no credit card, with referrals included rather than paywalled. That’s enough to actually validate an idea before you pay anything. And when you do pay, the ceiling is high and the price is flat.
Where a competitor is the better choice: if you need an embeddable form inside your existing site today, pick something else for now. WaitlistMaster runs on hosted pages you can map to your own domain, with a REST API for custom integrations. Embeds are in progress, not shipped.
ALTCHA's answer
JavaScript and Svelte.
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.
WaitlistMaster's answer:
Solo founders, indie hackers, and small product teams launching something new — SaaS products, mobile apps, online courses, and newsletters.
The typical user is pre-revenue and pre-launch. They have an idea they believe in, a landing page or a half-built product, and a need to know whether anyone wants it before they spend six more months building. They’re cost-sensitive because they aren’t earning yet, and time-sensitive because the waitlist isn’t the project — it’s the thing standing between them and the project.
A secondary group: developers who want waitlist infrastructure they can call from code rather than a dashboard they have to click through. That’s who the REST API is for.
Share your experience with using ALTCHA and WaitlistMaster. For example, how are they different and which one is better?
Recommendations tracked on public social media and blogs since March 2021.


ALTCHA won on the boring things. It is open source, self-hosted and collects nothing, and it ships official libraries in both Go and PHP, the two languages our two layers already speak. So the same protocol runs twice on every store, by... - Source: dev.to / about 1 month ago
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 / 6 months ago
Here's how PoW works for form protection (using the ALTCHA wire format):. - Source: dev.to / 7 months ago
Tracking WaitlistMaster since Nov 2026.
When comparing ALTCHA and WaitlistMaster, you can also consider the following products.

reCAPTCHA is a free security service that protects your websites from spam and abuse.
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A waitlist helps you validate your product idea and build hype — Waitlister helps you create an effective waitlist.
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Do you use a captcha to keep out bots? hCaptcha is a drop-in replacement for reCAPTCHA that earns website owners money and helps companies get their data labeled.
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Build a viral waitlist of early users before you launch.
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Cloudflare's service for any company to replace CAPTCHAs and deliver a better experience to web visitors.
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Akismet is a spam fighting service that protects millions of WordPress sites from comment and contact form spam.
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