Secure Cookie Generator

Generate a hardened cookie

Cookies that carry sessions and authentication are a prime target for attackers, so they should be set with protective attributes. This generator builds a Set-Cookie header with the three key security flags: Secure, which restricts the cookie to HTTPS; HttpOnly, which hides it from JavaScript to blunt cross-site scripting theft; and SameSite, which controls whether the cookie is sent on cross-site requests to defend against cross-site request forgery. You can also set the path and lifetime.

The tool warns you that SameSite None requires the Secure flag, a rule browsers enforce.

Why cookie flags matter

A session cookie without HttpOnly can be stolen by any injected script, and without Secure it can leak over an unencrypted connection. SameSite Strict or Lax stops the cookie from being sent automatically on requests originating from other sites, which neutralises many cross-site request forgery attacks. Together these flags turn a risky cookie into a hardened one.

Use Strict for the strongest protection where it does not break legitimate cross-site navigation, and Lax as a sensible default. Keep the lifetime as short as your application allows. All generation happens locally in your browser.

Related tools

• Password Strength Checker — Measure password strength by entropy and pattern analysis rather than character-class rules. Checked entirely in your browser.
• Password Generator — Generate strong random passwords and passphrases in your browser using the Web Crypto API. Nothing is transmitted, logged or stored.
• Hash Generator — Generate MD5, SHA-1, SHA-256 and SHA-512 hashes in your browser. Compare checksums and verify file integrity with nothing uploaded to a server.
• Base64 Encoder/Decoder — Encode and decode Base64 in your browser, including URL-safe Base64 and UTF-8 text. Handles files and data URIs locally with nothing uploaded.