Observatory
developer.mozilla.org/en-US/observatoryTest HTTP security headers such as CSP and HSTS, then review recommendations for improving a site.
Looking for something like Clearstar? Here are 24 alternatives, ranked by how closely they match it on purpose, features and platforms. Of these, 1 are free or have a free plan and 2 are open source.
Clearstar reviews protocol governance, permissions, contracts, and oracles, then recommends fixes through its qualitative diligence process.
| # | Alternative | Pricing | Open source | Platforms |
|---|---|---|---|---|
| 1 | Observatory | — | Not stated | Web |
| 2 | Asymmetric Research | — | Not stated | Web |
| 3 | Karma | — | Yes | Android |
| 4 | Pentest Contracts | — | Not stated | — |
| 5 | Agentic Radar | — | Yes | — |
| 6 | OTP Auth | Freemium | Not stated | iOS, Web |
| 7 | Mozilla SSL | — | Not stated | Web |
| 8 | challenges.re | — | Not stated | Web |
| 9 | GoPlus Locker V3 | — | Not stated | Web |
| 10 | NVD | — | Not stated | Web |
Test HTTP security headers such as CSP and HSTS, then review recommendations for improving a site.
Asymmetric Research provides security partnerships for L1 and L2 blockchains and DeFi protocols, including engineering and threat-response work.
Karma Firewall is an Android firewall that states it requires no internet permission and intercepts no allowed user traffic.
Adapt this collection of contract templates for penetration testing engagements.
Agentic Radar scans agent workflows for security issues and helps developers review potential risks.
Manage two-factor authentication codes with OTP Auth, an iOS app listed on the App Store.
Generate secure SSL configurations for selected web, database, and mail software.
Solve reverse engineering challenges published on challenges.re, a challenge-focused site.
GoPlus offers Web3 security tools including audits, APIs, a user security hub, and a browser extension.
Search the National Vulnerability Database, a public resource for vulnerability information.
View Toronto Police calls for service on a map that updates in real time, according to the supplied page description.
Add proof-of-work verification to websites with mCaptcha, a privacy-focused automated CAPTCHA system.
WhatsMyDNS checks DNS record propagation across global resolvers for record types including A, AAAA, MX, and TXT.
Use Metasploit to find security issues, verify mitigations, and manage authorized penetration testing assessments.
The Snyk Security Database provides vulnerability details and remediation guidance for packages and cloud configurations.
The URL Decoder and Encoder converts text between encoded and decoded forms, including JavaScript URLs.
Lucia was deprecated in March 2025. The website was updated in July 2026 and points to code/auth_session.ts as a single-file replacement for the NPM package and to the Auth Book for auth information.
DNSPerf compares the performance and uptime of enterprise and commercial DNS providers.
Search a community-curated collection of bug bounty writeups and learning resources.
UUID Tools generates individual or bulk UUIDs and supports multiple UUID versions.
Test a browser for privacy leaks, including exposed IP addresses, device information, and fingerprinting risks.
Fraunhofer FKIE maintains Malpedia, a reference that organizes information about malware families.
Discover hosts and map networks with Nmap, a network exploration and security scanning tool.
See what information a website can access from your browser with Webkay, a browser data demonstration.
Alternatives are suggested from the purpose and features described in our listings. Different pages for the same product appear once. Read each description to check whether it fits your task. How we choose alternatives · Suggest an alternative