Security Basics for Web Developers: Practical Checklist

Security can seem daunting, but many common vulnerabilities are preventable with pragmatic steps. This checklist targets web developers who want to reduce risk without becoming security experts overnight.

Frontend security practices

• Sanitize user-provided content before injecting into the DOM; avoid innerHTML when possible.
• Use Content Security Policy (CSP) to restrict script sources and mitigate XSS attacks.
• Protect authentication tokens: store them in secure, httpOnly cookies when possible instead of local storage.

Server-side practices

• Validate and sanitize all input server-side, even if client-side validation exists.
• Use parameterized queries or an ORM to avoid SQL injection.
• Rate-limit public endpoints and implement exponential backoff for abusive behavior.

Network & deployment

• Enforce TLS with HSTS and redirect HTTP traffic to HTTPS.
• Use secure headers: HSTS, X-Content-Type-Options, X-Frame-Options, and Referrer-Policy.
• Scan container images and dependencies for known vulnerabilities as part of CI.

Developer tooling

• Automate dependency updates and use tools like Snyk, Dependabot, or OSS security scanning in CI.
• Run static analysis and linters to detect dangerous patterns early.
• Integrate security tests into your CI pipeline for regressions.

Incident preparedness

Have a documented incident response plan, ownership of critical components, and a communication template for informing users in case of a breach. Regularly back up configuration and have an emergency rollback plan for deployments.

“Security is continuous improvement; prioritize small, high-impact changes that reduce the attack surface.”

Following these steps will reduce common risks and make your application safer for users. Start with the most impactful measures — CSP, TLS, and dependency scanning — and iterate from there.