60 Free Security & Developer Tools Every Vibe Coder Should Bookmark

Quick answer: Sixty free, no-signup tools cover the security and visibility gaps AI app generators leave behind. These include live checks for SSL, security headers, and exposed .env files, plus browser-local utilities like JWT debuggers and secret scanners. Run these checks after every deploy to ensure your vibe-coded app is production-ready.

By Daniel A · Kraftwire Software

The 60 free tools every vibe coder should bookmark include live site checkers for SSL, security headers, and CORS, browser-local utilities like JWT debuggers and secret scanners, and specialized generators for API keys and CSP policies. These tools close the security and visibility gaps left by AI app generators like Lovable, Bolt.new, and Cursor by providing instant, no-signup verification of production settings.

What Do These 60 Free Tools Actually Do?

AI app generators are designed to ship functional code at high velocity, but they often prioritize "it works" over "it's secure." This creates a "vibe coding" gap where the application looks perfect in a preview but lacks the hardening required for production. These 60 free, no-signup tools allow you to audit your application in seconds. They are categorized into live checks (which probe your public URL), local utilities (which process sensitive data entirely in your browser), and generators that help you build secure configurations from scratch.

These tools are designed to catch those critical failures before they are exploited. By running these checks after every deploy, you ensure that your vibe coding guardrails are actually in place.

Why Do Vibe Coders Need These Tools?

Shipping with platforms like Lovable, Cursor, Bolt.new, v0, Replit, or Windsurf allows you to move from a prompt to a live URL in minutes. However, the deployment layer is often where security breaks down.

AI models often suggest permissive defaults to ensure a smooth developer experience. For example, an AI might suggest a wildcard Access-Control-Allow-Origin: * header just to fix a "blocked by CORS" error, unknowingly opening your API to cross-site data theft.

Which Live Site Checks Should You Run After Every Deploy?

These tools interact with your live production environment. They see exactly what an attacker or a search engine sees.

The SSL Certificate Checker is your first line of defense.

The Security Headers Checker is perhaps the most important tool for vibe-coded apps. It inspects your HTTP response headers for Content Security Policy (CSP), HSTS, and X-Frame-Options. AI-generated apps frequently ship with a grade of "F" here because these headers require manual configuration on the hosting platform (Vercel, Netlify, etc.).

The DNS Security Checker and DNS Lookup tools verify that you have implemented DNSSEC and CAA records. DNSSEC prevents DNS spoofing, while CAA (Certificate Authority Authorization) records prevent unauthorized CAs from issuing certificates for your domain.

The CORS Tester is critical for any app with a backend. It checks if your API reflects the Origin header or allows credentials on a wildcard origin. This is a common windsurf security risk when AI agents try to "fix" connectivity issues by making the API too permissive.

The Email Security Checker verifies SPF, DKIM, and DMARC. If these are missing, your app's transactional emails (like password resets) will land in spam, and attackers can easily spoof your domain to phish your users.

The Exposed Files Scanner probes for the most dangerous mistake a vibe coder can make: leaving a .env file or .git directory public.

The security.txt Validator checks for the RFC 9116 standard file. This tells ethical hackers how to report bugs to you privately instead of posting them on X (formerly Twitter).

Which Developer Utilities Run Entirely in Your Browser?

When dealing with real tokens or secrets, you should never send them to a third-party server. These tools use client-side JavaScript to keep your data in your tab.

The JWT Debugger allows you to decode JSON Web Tokens to check for correct claims and expiration times. Since it runs locally, your production tokens are never leaked. This is a staple for application security audits.

The CSP Evaluator takes a complex Content Security Policy string and highlights "unsafe-inline" or "unsafe-eval" directives that could allow XSS. AI-generated CSPs are often too broad; this tool helps you tighten them.

The Password Strength Checker uses entropy calculations to tell you if your "secure" password can be cracked in seconds. Use this to test the default passwords your AI might be generating for database users.

The Hash Generator and SRI Hash Generator are essential for integrity. The SRI tool creates hashes for third-party scripts (like Google Analytics or Stripe.js) so that if the CDN is hacked, your site won't execute the malicious code.

The Base64 Encoder / Decoder is a Swiss Army knife for vibe coders. It’s perfect for peeking into data URLs or decoding the configuration blobs that AI platforms often use to pass state.

Which Analyzers Catch Leaked Secrets and Spoofed Emails?

The Secret Scanner is a mandatory stop before you push code to GitHub. Paste your code or your .env file to check for OpenAI keys, Stripe secrets, or Supabase service-role keys.

The .env File Linter specifically looks for "leaky" prefixes. For instance, in Next.js, any variable starting with NEXT_PUBLIC_ is sent to the browser. This linter ensures you haven't accidentally prefixed a secret key with a public tag.

The Email Header Analyzer is your defense against phishing. If you receive a "security alert" about your app, paste the headers here to see if the SPF/DKIM signatures actually match the sender.

The robots.txt Tester and User-Agent Parser help you manage how bots see your site. This is vital for Answer Engine Optimization (AEO), ensuring that ChatGPT and Claude can crawl your content to cite you in AI answers.

The Punycode Converter helps you detect homograph attacks, where an attacker registers a domain that looks identical to yours but uses different character sets (e.g., replacing 'o' with a Greek 'ο').

Which Generators Create Passwords, Keys, and Tokens Locally?

Stop using "password123" for your dev database. These generators produce cryptographically secure strings in your browser.

The Password Generator and API Key Generator allow you to specify length and character sets. The UUID Generator supports both v4 (random) and v7 (time-ordered) IDs, which are better for database performance.

For advanced auth, use the JWT Generator for testing HS256 signatures, the HMAC Generator for verifying webhooks from Stripe or GitHub, and the PKCE Generator for secure mobile/SPA login flows.

The CSP Generator helps you build a Content Security Policy from scratch, while the Basic Auth Generator ensures your Authorization headers are correctly Base64 encoded.

The AES Encrypt / Decrypt tool uses AES-256-GCM to let you securely encrypt a string before sending it over an insecure channel, and the .gitignore Generator ensures you never accidentally commit your node_modules or .env files.

Converters, Testers, and References

These tools handle the "boring" parts of development that AI often hallucinates or gets slightly wrong.

The JSON Formatter and JSON to TypeScript converter are essential for working with APIs. When an AI gives you a giant JSON blob, these tools help you structure it for your code. Use the CSV to JSON Converter for quick data migrations.

The cURL to fetch Converter is a lifesaver when you have a working terminal command but need to move it into a Lovable or Bolt.new frontend.

For debugging, use the Unix Timestamp Converter, Case Converter, and Number Base Converter. The Text Diff Checker is perfect for comparing two versions of a prompt or a configuration file.

References like the HTTP Status Codes guide and Port Number Lookup help you understand why your app is throwing a 403 or why port 5432 should never be open to the public internet. The Regex Tester and Cron Parser ensure your logic and schedules are correct before you deploy them.

How Do You Make Sure People and AI Can Find Your App?

Security is about keeping the bad guys out; visibility is about letting the right users in.

The SEO Checker audits your H1 tags, meta titles, and descriptions. AI generators often leave these as "My App" or "Vite + React," which kills your search rankings.

It tests if your site is "AI-friendly." If your content is buried behind complex JavaScript or blocked in robots.txt, ChatGPT and Perplexity won't be able to recommend your app to users. This is a core part of any vibe coding security checklist.

The Meta Tags Generator provides a live preview of how your site will look on Google, X, and Facebook. Pair this with the UTM Link Builder to track where your traffic is actually coming from.

Go Deeper into Security and Performance

Once a tool identifies a problem, these guides provide the step-by-step fix:

• JWT security guide · Learn how to store tokens safely in localStorage vs. cookies.
• CORS explained · Why origin reflection is the most common API security mistake.
• AEO / AI visibility guide · How to optimize your site for the LLM era.
• Find exposed secrets · A guide to cleaning up your git history after a leak.
• DNS records explained · From A records to the security-focused CAA.
• WCAG color contrast guide · Ensure your app is accessible and legally compliant.
• Meta tags for SEO · The definitive list of tags that drive clicks.

Run the Full Scan

While these 60 tools are perfect for specific tasks, a manual check is easy to forget. Checking speed, security, and SEO one by one takes time you could spend building.

For a comprehensive audit, run a free scan at simplyscan.io. It evaluates 8 dimensions · including security, speed, SEO, and GDPR compliance · in about 30 seconds. You get two free rescans to verify your fixes. Whether you are building with Lovable, Bolt, or Cursor, a full scan ensures that your "vibe" is backed by solid engineering.

FAQ

Are free online security tools safe to use with real secrets?

It depends on where the processing happens. Tools that run entirely client-side, like SimplyScan's JWT debugger, hash generator, and secret scanner, never upload your data to a server. This makes them safe for real tokens. Always look for a "local processing" guarantee before pasting sensitive data into any web tool.

Do free single-purpose security tools replace a full security scan?

No. Single-purpose tools are excellent for verifying a specific fix, like a new CSP header or a DNS record. However, they cannot see the "whole picture." A full scanner like SimplyScan checks for cross-category issues · like how a slow server response (speed) might be caused by a misconfigured firewall (security).

What security checks should I run right after deploying an app?

At a minimum, run an SSL check, a security headers audit, and an exposed files scan. These three checks catch the most common "day zero" errors in vibe-coded apps, such as missing HTTPS redirection, lack of clickjacking protection, or a public .env file containing your database password.

Why do AI-generated apps have so many security gaps?

AI models are trained on vast amounts of code, much of which is boilerplate or educational. They often prioritize getting a feature to work quickly over implementing "defense in depth." This results in missing security headers, permissive CORS policies, and a lack of input validation · gaps that developers must manually close.

Do I need to pay for security tooling as a solo developer?

For the fundamentals, no. You can achieve a high level of security using free tools for SSL, DNS, and header verification. Paid tools are generally for automated monitoring, team collaboration, or deep compliance reporting. For most vibe-coded projects, a combination of free tools and a SimplyScan Pro report is sufficient.

What is an AI visibility (AEO) check and why does it matter?

An AEO check determines if AI agents like ChatGPT or Claude can access and understand your website. As more users move from traditional search to AI assistants, being "crawlable" by LLMs is as important as being indexable by Google. If your site blocks these bots, you lose a massive source of modern traffic.