15 Free Security Tools Every Vibe Coder Should Bookmark

AI generators optimize for "it works," not "it's safe." These 15 free, no-signup tools each check one thing in seconds · from your TLS certificate to whether ChatGPT can find you.

By Daniel A · Kraftwire Software

2026-07-03 · 8 min read

Key takeaway

AI app generators optimize for "it works," not "it's safe" · so the security gaps they leave are yours to catch. These 15 free, no-signup tools each check one thing in seconds, from your TLS certificate to whether ChatGPT can even find you. Bookmark them, run them before and after every deploy, and you close the most common holes without becoming a security expert.

Why vibe coders need these

Shipping fast with Lovable, Cursor, Bolt.new, v0, Replit, or Windsurf is genuinely great · you go from idea to live app in an afternoon. But the model writing your code is trained to make things run, not to lock them down. It will happily leave a permissive CORS policy, ship without security headers, or scaffold a `.env` file that ends up reachable in production.

None of that shows up in your preview. Everything looks fine until someone finds the gap. The good news is that most of these issues are cheap to catch · you point a free tool at your URL, read the result, and fix it. Below are 15 tools worth keeping one click away, grouped by how you use them. Want them in one place? Here are [all 15 free tools](/tools).

Live site checks (point them at a URL or domain)

These run against your deployed site. Ship, then run them · they see what the public sees.

The [SSL Certificate Checker](/tools/ssl-checker) confirms your HTTPS certificate is valid, not expired, and served with a modern TLS version. An expired or misconfigured certificate throws scary browser warnings that make users bounce instantly, and it can quietly break API calls between your services. Check it after launch and again before renewals lapse.

The [Security Headers Checker](/tools/security-headers) inspects the HTTP response headers that browsers rely on to defend your users · CSP, HSTS, X-Frame-Options, and more · and hands you a grade from A to F. AI-generated apps almost always ship with these missing, which leaves the door open to clickjacking, content injection, and protocol downgrade attacks. The letter grade makes it obvious how much work is left.

The [DNS Security Checker](/tools/dns-security) looks at DNSSEC and CAA records on your domain. DNSSEC stops attackers from forging DNS answers and quietly redirecting your visitors, while CAA records limit which certificate authorities are allowed to issue certs for you. Both are set-and-forget protections that most vibe-coded projects never turn on.

The [CORS Tester](/tools/cors-tester) checks how your API responds to cross-origin requests, catching origin reflection and credential-leak misconfigurations. A too-generous CORS policy · the kind an AI adds to "just make the fetch work" · can let any website read authenticated data on behalf of your logged-in users. This is one of the most common and most dangerous defaults to inherit.

The [Email Security Checker](/tools/email-security) verifies your SPF, DKIM, and DMARC records. Without them, anyone can send email that looks like it came from your domain · phishing your users and torching your deliverability so your real emails land in spam. If your app sends password resets or receipts, this matters even if you never thought of yourself as "doing email."

The [Exposed Files Scanner](/tools/exposed-files) probes for sensitive files that should never be public · `.env` secrets, `.git` directories, and stray backups. A single exposed `.env` can hand over your database credentials and API keys, and it happens more than you'd think when a build step copies the wrong folder. Run this the moment you go live.

The [security.txt Validator](/tools/security-txt) checks for a valid `security.txt` file, the standard defined in RFC 9116 that tells researchers how to report a vulnerability to you. It won't stop an attack, but it gives the good-faith finder a clear path to reach you instead of dumping your bug publicly. It's a five-minute addition that signals you take security seriously.

Developer utilities (100% in your browser, nothing uploaded)

These run entirely client-side · your data never leaves the tab · so they're safe to use with real tokens, secrets, and payloads.

The [JWT Debugger](/tools/jwt-debugger) decodes and analyzes JSON Web Tokens so you can see exactly what's inside the ones your auth flow issues. It's the fastest way to confirm claims, expiry, and algorithm when a login isn't behaving. Because it runs locally, you can paste a live token without shipping it to some stranger's server.

The [CSP Evaluator](/tools/csp-evaluator) grades a Content-Security-Policy string and flags the weak spots · `unsafe-inline`, wildcards, and other bypasses that make a policy look protective while doing nothing. CSP is fiddly to get right, and AI-suggested policies are often permissive to the point of being useless. Paste yours and see where it actually holds.

The [Password Strength Checker](/tools/password-strength) estimates entropy and crack-time for a password so you can sanity-check the rules you enforce on users. It's a quick way to feel why an 8-character minimum is weak and a passphrase is strong. Use it to calibrate your own signup requirements, not just to test one password.

The [Hash Generator](/tools/hash-generator) produces MD5 and SHA-1/256/384/512 digests on demand. Handy for verifying file integrity, comparing checksums, or generating a quick fingerprint during debugging. Everything is computed in your browser, so it's fine for sensitive input.

The [SRI Hash Generator](/tools/sri-hash) creates Subresource Integrity hashes for scripts and styles you load from a CDN. Adding an SRI hash means the browser refuses to run that file if it's been tampered with · protecting you if the CDN is ever compromised. If your AI-built app pulls in third-party scripts, this is a simple hardening win.

The [Base64 Encoder / Decoder](/tools/base64) encodes and decodes Base64 with proper UTF-8 handling, so accented characters and emoji survive the round trip. It's the everyday tool for peeking at data URLs, tokens, and config blobs. Local and instant, with nothing uploaded.

Get found

Security keeps you safe · these two make sure the right people and machines can actually reach you.

The [SEO Checker](/tools/seo-checker) grades your on-page SEO · titles, meta descriptions, headings, and the structural basics search engines read first. AI generators are notorious for shipping a default title on every route and no meta descriptions at all. A quick grade tells you what's costing you visibility before you spend a cent on ads.

The [AI Visibility Checker (AEO)](/tools/ai-visibility) tests whether assistants like ChatGPT, Claude, and Perplexity can crawl and cite your site. More people now ask an AI instead of searching, and if your pages block those crawlers or hide content behind heavy JavaScript, you're invisible to them. This checks that you're answerable, not just indexable.

Go deeper

Once a tool flags something, these guides walk through the fix in plain language:

[JWT security](/blog/jwt-security-guide) · how tokens go wrong and how to store and validate them safely

[Content Security Policy guide](/blog/csp-guide) · building a CSP that actually blocks attacks without breaking your app

[DNSSEC and CAA](/blog/dnssec-caa-guide) · what these DNS records do and how to turn them on

[security.txt (RFC 9116)](/blog/security-txt-guide) · writing a disclosure file researchers can use

[CORS misconfigurations](/blog/cors-explained) · why origin reflection is dangerous and how to scope access

[AEO / AI visibility](/blog/ai-visibility-aeo-guide) · getting cited by ChatGPT, Claude, and Perplexity

Run the full scan

Each of these tools checks one thing well, and bookmarking them turns a vague worry into a five-minute habit. Run the live-site checks after every deploy, keep the browser utilities handy while you build, and use the visibility tools before you promote anything.

When you want the whole picture at once instead of tool by tool, run a full scan at [simplyscan.io](https://simplyscan.io) · it runs 51+ checks across 14 categories in about 30 seconds and hands you a prioritized list of what to fix first. Ship fast, then take half a minute to make sure what you shipped is safe.