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Castle VS Keylight.dev

Compare Castle VS Keylight.dev and see what are their differences

Castle

The easiest way to protect your users from getting hacked

Rating
0 reviews
Alternatives Is it good?
Keylight.dev

The simplest way to license your app.

Rating
5.0 · 1 review
Pricing
Open source Freemium $19 / Monthly (Up to 2000 licenses active.)
Alternatives Is it good?
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Note: These products don't have any matching categories. If you think this is a mistake, please edit the details of one of the products and suggest appropriate categories.

Which is more popular?

Keylight.dev might be a bit more popular than Castle. We know about 4 links to it since March 2021 and only 4 links to Castle.

social mentions
4 vs 4
Security & Privacy popularity
100% vs 0%
alternatives listed
240+ vs 1

Base details

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

Castle
Keylight.dev
Website castle.io keylight.dev
Pricing
Official pricing
Open source Freemium $19 / Monthly (Up to 2000 licenses active.) Official pricing
Platforms —
Web
Company — Startup from Belgium · 1 - 9 employees · 2026
Listed in
Antivirus Security & Privacy Security Privacy +1
Developer Tools Software Development License Management Productivity Tech Web App Tool +4

About Castle and Keylight.dev

In their own words, as submitted to SaaSHub.

Castle
Keylight.dev

No description of Castle yet.

Keylight sits between your payment provider and your app. Licenses, activations, customers, and usage all live here. Switch providers, or run several, without shipping a new build.

Read more about Keylight.dev

Features and specs

What each product offers, as listed by its team.

Castle 5 features
Keylight.dev 16 features
  • Comprehensive Security
    Castle provides robust security features, including real-time threat detection and response, which help safeguard against a range of online threats.
  • Ease of Integration
    Castle offers straightforward API documentation and support for multiple programming languages, which makes it easy to integrate into existing systems.
  • User Behavior Tracking
    The platform's ability to monitor and analyze user behavior can help in identifying suspicious activities and enhancing overall security.
  • Customizable Rules
    Users can create custom security rules tailored to the specific needs of their applications, allowing for more precise threat prevention.
  • Scalability
    Castle's infrastructure is designed to handle varying levels of traffic, making it suitable for both small businesses and large enterprises.

Possible disadvantages

  • Cost
    The advanced features and comprehensive security solutions provided by Castle can be expensive, which may be a drawback for smaller businesses with limited budgets.
  • Complexity
    While Castle offers a range of powerful features, the platform's complexity may require a steep learning curve for new users.
  • Potential Overhead
    Implementing and maintaining Castle's security solutions may add extra overhead to development and operational processes.
  • Dependency on Third-Party Service
    Relying on an external security service means that any downtime or issues with Castle could impact the security of the integrated applications.
  • License Management
    Create, validate, revoke, and manage software licenses from one dashboard.
  • Device Activations
    Limit how many devices can use a license and manage individual activations.
  • Offline Access
    Keep apps working securely without a constant internet connection using signed offline leases.
  • License States
    Handle trial, free, paid, expired, limited, and grace-period access through one consistent state.
  • Payment Provider Integrations
    Connect Stripe, Paddle, Lemon Squeezy, Polar, Gumroad, and other payment platforms.
  • Provider Independence
    Change payment providers or use multiple providers without rebuilding your app’s licensing system.
  • Swift SDK Integration
    Add licensing to macOS and iOS apps using a native Swift package.
  • Secure License Validation
    Protect license data with cryptographic signatures and tamper-resistant validation.
  • Trials and Free Tiers
    Configure trials, free plans, fallbacks, and upgrade paths without building custom logic.
  • Customer Dashboard
    View licenses, customers, devices, activations, plans, and access status in one place.
  • License Analytics
    Track activations, active licenses, usage, and customer activity.
  • Key Rotation
    Rotate SDK signing keys without breaking older application versions.
  • Webhook Synchronization
    Convert payment, renewal, refund, cancellation, and subscription events into license updates.
  • Device-Bound Storage
    Store license data securely on the customer’s device without unnecessary Keychain prompts.
  • REST API
    Connect custom backends, checkout systems, and internal tools to Keylight.
  • Agentic Orchestration
    CLI usable by AI Agents to run the whole setup and more.

Analysis

An editorial look at what each product does well and who it suits.

Castle
Keylight.dev

Overall verdict

  • Castle is a well-regarded solution in the security space, known for its user-friendly interface and effectiveness in preventing unauthorized access and reducing fraud risk. It is considered a good choice for businesses seeking to enhance their security protocols.

Why this product is good

  • Castle provides security solutions that focus on protecting user accounts and preventing fraud. It offers features such as anomaly detection, user monitoring, and real-time alerts to help businesses secure their applications and data. The platform is particularly useful for companies that prioritize user security and privacy.

Recommended for

  • E-commerce platforms
  • Financial services
  • Online businesses
  • SaaS providers
  • Organizations focusing on user account security

Overall verdict

  • I don't have verified, up-to-date information about Keylight.dev specifically, so I can't confirm its quality, features, or reliability. It may be a newer or niche tool that isn't well-documented in my training data. I'd recommend checking recent user reviews, the official website's documentation, and community forums (like GitHub, Reddit, or Twitter) for firsthand feedback before making a decision.

Why this product is good

  • Unable to verify specific features, pricing, or performance claims for this product
  • No confirmed user reviews or independent testing data available
  • Cannot confirm company legitimacy, support quality, or security practices without direct verification

Recommended for

  • Users willing to conduct their own due diligence by visiting the official site directly
  • Developers who can test the product via a free trial or demo before committing
  • Anyone who checks third-party review sites, GitHub issues, or community discussions for real user experiences

Videos

Walkthroughs and reviews on video.

Castle 3 videos + Add
Keylight.dev 0 videos + Add

Kingdom Come, Deliverance, CASTLE review

More videos

  • - Castle TV Series Review
  • - What Really Went Wrong on Castle

No Keylight.dev videos yet. You could help us improve this page by suggesting one.

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
Castle
Keylight.dev
100% 100%
Security & Privacy
0% 0%
0% 0%
Tool
100% 100%
100% 100%
Security
0% 0%
0% 0%
Productivity
100% 100%

Questions & Answers

As answered by people managing Castle and Keylight.dev.

What makes your product unique?

Keylight.dev's answer:

Keylight keeps app licensing separate from payments. You can use Stripe, Paddle, Lemon Squeezy, Polar, Gumroad, or your own checkout without tying your app to one provider.

It handles license keys, device activations, trials, free tiers, offline access, grace periods, and signed license state through one SDK.

Why should a person choose your product over its competitors?

Keylight.dev's answer:

My goal is to make all apps work with Keylight. So all of your licenses, from any types of apps, is going through Keylight for analytics, customer portal, support, ...

Most licensing tools are bundled into a payment provider. Keylight is built as an independent licensing layer.

That means you can change payment providers, sell through multiple platforms, or change your pricing model without rebuilding licensing inside your app.

It also gives developers a ready-made SDK and dashboard instead of requiring them to build and maintain their own licensing backend.

How would you describe the primary audience of your product?

Keylight.dev's answer:

Keylight is primarily built for independent developers and software companies selling apps directly to customers.

Its main audience includes:

macOS and iOS developers Web app and SaaS developers Developers selling outside app stores Teams migrating from a payment provider’s built-in licensing Developers who need trials, device limits, offline access, and license analytics

What's the story behind your product?

Keylight.dev's answer:

Keylight started because I kept rebuilding the same licensing systems for different apps: license keys, trials, activations, offline access, device changes, and all the edge cases that come with them.

I also did not want licensing to be controlled by whichever payment provider an app happened to use.

So I built Keylight as a standalone layer between the app and the payment provider. Payment platforms send events to Keylight, and the app receives one consistent license state through the SDK.

Who are some of the biggest customers of your product?

Keylight.dev's answer:

That's confidential.

Which are the primary technologies used for building your product?

Keylight.dev's answer:

Swift and Swift Package Manager for the Apple SDK Rust SDK / JS SDK / C# SDK / C++ SDK TypeScript React Next.js Stripe Connect and payment-provider webhooks Cryptographic signatures for secure, offline-capable licenses REST APIs for application and provider integrations

User comments

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

Log in or Post with

Reviews and articles

External articles and on-site reviews we used to compare the two products.

Castle no reviews yet
Keylight.dev 5.0 · 1 review

We have no reviews of Castle yet. Be the first one to post

Social recommendations and mentions

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

Castle 4 mentions
Keylight.dev 4 mentions
  • Precursor
    This (agent detection) is now a kind of emerging space. Obviously it'll get much more important, too. Other products in the space: - Foil (https://usefoil.com/), I'm biased, a friend is building this - Kasada https://www.kasada.io/ -... - Source: Hacker News / 2 months ago
  • Ask HN: Who is hiring? (April 2025)
    Castle (https://castle.io) | Senior ML Engineer | Senior R&D Detection Engineer | REMOTE (Europe/EMEA) | Full-time Hi HN! I’m Antoine, Head of Research at Castle. We’re a YC-backed Series A startup helping companies like Canva,... - Source: Hacker News / over 1 year ago
  • If you need help with distrokid related issues inbox me i used to work for distrokid
    Tell me about the fingerprint, they using castle.io within segment.com ? Or something else? And what they watching? Source: over 3 years ago

View more

  • How offline license activation actually works
    You don't want to hand-roll Ed25519 and lease parsing. Most licensing SDKs hide this behind a couple of calls. With Keylight, for example, the offline path collapses to: activate once, then a local checkOnLaunch() that verifies the lease... - Source: dev.to / 3 months ago
  • I compared the licensing tools for my indie Mac app — the honest breakdown
    Full disclosure: I now build Keylight, so weigh this accordingly — I'm telling you the seam it's designed for, not that it wins every row. - Source: dev.to / 3 months ago
  • How to add license keys to a SwiftUI macOS app (in under an hour)
    Full docs and the free tier are at keylight.dev. If you're on Tauri or Electron instead of native Swift, the same SDK pattern exists in JS/Rust. - Source: dev.to / 3 months ago

View more

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