🛡️Subresource Integrity (SRI) Hash Generator Documentation & Guide
Security & Privacy
The Subresource Integrity (SRI) Hash Generator creates cryptographic SHA-256, SHA-384, and SHA-512 digests and ready-to-paste HTML embed tags for external scripts and stylesheets, protecting web applications from CDN compromise and supply chain injection attacks.
📋How to Use This Tool
- Upload or Paste Asset Content: Upload any local JavaScript (.js), CSS (.css), or WebAssembly (.wasm) file, or paste raw code into the textarea.
- Specify CDN Resource URL: Optionally enter the public CDN URL where the asset will be hosted to generate complete script or link tags.
- Select Tag Format and Algorithm: Choose between script, stylesheet link, or preload tags, and select SHA-384 (W3C recommended) or SHA-512.
- Copy Embed Tag or Hashes: Copy the generated HTML snippet with integrity and crossorigin attributes, or copy individual cryptographic hashes.
⚙️Technical Specifications and W3C SRI Security Architecture
Subresource Integrity (W3C Recommendation) is a browser security mechanism that enables web developers to verify that third-party resources (such as scripts hosted on unpkg, cdnjs, or jsDelivr) have not been maliciously tampered with or modified.
• W3C Specification: RFC-compliant base64-encoded digests prefixed with the algorithm name (e.g., sha384-[base64])
• Supported Hash Algorithms: SHA-256, SHA-384, and SHA-512 calculated via Web Crypto API (crypto.subtle.digest)
• Cross-Origin Requirement: SRI requires the crossorigin="anonymous" attribute to bypass CORS restrictions on external origins
• Browser Enforcement: If the downloaded CDN resource hash differs by even 1 bit, the browser blocks execution immediately
• Client-Side Privacy: 100% in-browser hashing; proprietary code and scripts are never uploaded to remote servers
Implementing SRI is an essential defense against CDN supply chain poisoning and compromised third-party dependencies.
💡Practical Subresource Integrity Use Cases
- Securing public CDN scripts (React, Vue, Tailwind, Alpine) against malicious third-party tampering.
- Meeting strict SOC2, ISO 27001, and PCI-DSS compliance requirements for external asset integrity.
- Locking production stylesheet versions to prevent unintended visual breakage from upstream CDN overwrites.
100% Client-Side Privacy Guarantee:All calculations, text manipulation, cryptographic hashing, and media conversions execute exclusively within your local browser sandbox. Zero user inputs, financial amounts, credentials, or proprietary files are ever transmitted across networks or logged on external servers.
