HackproofHacks
Free tools

Free cybersecurity tools, built by penetration testers

Free, privacy-first tools to check the health of your website and API in seconds: inspect SSL certificates, grade your HTTP security headers, and map your subdomain attack surface. No account, no installs, and we never store what you check.

5 tools and counting
$0 always free
No logs checks never stored
10+ yrs real-world pentesting
The toolkit

One job each, done well

Each tool does one job well, explains what it finds in plain English, and tells you exactly how to fix it. Pick one to get started.

When a free check isn't enough

These tools sweep the surface. When you need real depth — a manual web-app or API penetration test, a vulnerability assessment, or ongoing monitoring — we test by hand and deliver a prioritised report your team can fix from.

Why it's free

Free security tools that respect your privacy

Most “free” online security scanners come with a catch: they make you sign up, throttle you behind a paywall, or quietly log and publish every domain you look up. Ours don’t. Every tool here is built by a working penetration-testing team, runs the real check (not a cached guess), explains the result in plain English, and forgets your input the moment it answers. No account, no API key, no stored history.

What you can check today

The SSL certificate checker reads the live TLS certificate a domain is serving and can email you before it expires — the one feature most certificate checkers are missing. The HTTP security header analyzer grades your security headers, deep-lints your Content-Security-Policy, audits your cookies and hands you copy-paste fixes for every major web server. The subdomain finder maps your externally visible attack surface using passive Certificate Transparency and DNS data — no intrusive scanning. Each one is a fast, focused first sweep of a website’s security posture.

When you need more than a tool

Automated checks are excellent at catching the obvious, high-impact mistakes — but real attackers chain subtle flaws across authentication, business logic and access control that no scanner can find on its own. That is where a human-led penetration test comes in. If a free tool here surfaces something concerning, it is usually worth a deeper look — and we are happy to help. Get in touch for a professional assessment.

FAQ

Free security tools — frequently asked questions

Are these cybersecurity tools really free?

Yes. Every tool on this page is completely free to use, with no account, sign-up, API key or credit card required. They are built and maintained by our professional penetration-testing team as a way to give the security community something genuinely useful — and to show how we work. The only time we ask for anything is the optional SSL expiry reminder, which needs an email address so we can notify you before your certificate lapses.

Do you store the domains or URLs I check?

No. Every tool processes your input in real time and returns the result to your browser only — we do not store, log, or publish the domains, URLs or hostnames you look up. The single exception is the SSL expiry reminder: if you opt in, we keep just the domain, your email address and your chosen reminder schedule, used solely to send those reminders and deleted the moment you unsubscribe.

Who are these free security tools for?

Developers, sysadmins, DevOps and SRE teams, security engineers, bug-bounty hunters, students and small business owners. If you run a website or an API, these tools help you spot the most common, highest-impact misconfigurations — an expiring TLS certificate, missing security headers, an exposed attack surface — before an attacker (or an outage) finds them first. No security expertise is required to read the results, because each one explains what it found and why it matters.

What is the difference between these tools and a professional penetration test?

These free tools run focused, automated checks against a single, visible part of your attack surface — your certificate, your headers, your subdomains. A professional penetration test is a manual, human-led engagement that chains together authentication flaws, business-logic bugs, injection, access-control gaps and more across your whole application and API, then delivers a prioritised report with proof-of-concept and remediation guidance. The tools are a great first sweep; a pentest is the deep assessment. If a free tool surfaces something worrying, that is usually a sign it is worth booking a full review.

Do I need to create an account to use them?

No account, no log-in, no installation. Open the tool, enter a domain or URL, complete a quick bot check, and you get your result instantly in the browser. Everything runs server-side on our infrastructure, so there is nothing to download and nothing to configure.

Can I use these tools on client or production websites?

Yes — the SSL checker, header analyzer and passive subdomain finder are non-intrusive: they read publicly available information (the certificate a server presents, the headers it returns, public Certificate Transparency and DNS records) and never attack, exploit or stress the target, so they are safe to run against production and client sites you are authorised to assess. As always, only test assets you own or have explicit permission to test.