What is Subresource Integrity (SRI)?

A W3C security feature that enables browsers to verify that files fetched from CDNs have not been tampered with.

How do I generate an SRI hash?

Paste the file URL or code into ScanSuite's SRI generator to receive a Base64-encoded hash with HTML markup.

Which algorithm is recommended for SRI?

W3C recommends SHA-384 (`sha384`) as the optimal balance of speed and security strength.

Why is crossorigin="anonymous" required for SRI?

CORS is required so browsers can inspect the cross-origin file bytes to compute the verification hash.

What happens if an SRI hash check fails?

The browser blocks execution of the script or stylesheet and logs a security error in the console.

Does SRI affect website loading speed?

No. Hashing takes less than a millisecond in browser memory during file parsing.

Can I use SRI for internal local scripts?

SRI is intended for third-party cross-origin scripts, but can be used locally for build validation.

Are my file contents saved on ScanSuite servers?

No. File hashing is performed client-side using browser Web Crypto APIs.

What is the format of an SRI attribute?

Formatted as `integrity="[algorithm]-[base64-hash]"` (e.g. `integrity="sha384-abc..."`).

Can I specify multiple SRI hashes in one tag?

Yes, separate multiple hashes with spaces inside the `integrity` attribute.

What happens if a CDN updates a script file without changing the URL?

The SRI check will fail because file bytes changed; you must update the SRI attribute whenever script contents change.

Can SRI protect against supply chain attacks?

Yes, it prevents malicious script replacements on third-party CDNs from executing in your visitors' browsers.

What is the difference between CSP and SRI?

CSP controls WHERE resources can be loaded from; SRI verifies WHAT content those resources contain.

Is SRI supported by all modern web browsers?

Yes, SRI is supported across Chrome, Firefox, Safari, Edge, and mobile browsers.

Is this SRI generator tool free?

Yes, ScanSuite provides free unlimited SRI hash generation without registration.

Can I generate SRI hashes for CSS stylesheets?

Yes, SRI works for both ` ` and ` ` tags.

How do I generate SRI hashes in OpenSSL CLI?

Run `openssl dgst -sha384 -binary file.js | openssl base64 -A`.

What does the Base64 output ending in = mean?

Standard Base64 padding characters ensuring binary alignment.

Free Subresource Integrity (SRI) Hash Generator

A Subresource Integrity (SRI) generator computes cryptographic Base64-encoded hashes (such as `sha384-...`) of remote CDN JavaScript files or CSS stylesheets, producing HTML `integrity` attributes that prevent browsers from executing tampered or hijacked third-party code.

Paste script URL or code content into ScanSuite's SRI generator, select target algorithms (`sha384` or `sha512`), and copy the generated `integrity="sha384-..."` HTML `<script>` or `<link>` snippet directly into your web pages.

Modern web applications rely heavily on Content Delivery Networks (CDNs) to serve third-party JavaScript libraries and CSS frameworks like Bootstrap, jQuery, and React. However, if a CDN provider is compromised or a supply chain attack occurs, malicious actors can inject web shells or keyloggers into those shared files.

Subresource Integrity (SRI) is a W3C security specification that allows browsers to verify that files fetched from third-party CDNs match expected cryptographic digests. ScanSuite's free SRI hash generator calculates Base64-encoded `sha256`, `sha384`, and `sha512` digests, generating ready-to-paste HTML tags in seconds for production deployment.

ScanSuite's free SRI hash generator calculates Base64 sha256, sha384, and sha512 Subresource Integrity attributes for CDN script and stylesheet tags, protecting websites against supply-chain attacks.

Frequently Asked Questions

What is Subresource Integrity (SRI)?: A W3C security feature that enables browsers to verify that files fetched from CDNs have not been tampered with.
How do I generate an SRI hash?: Paste the file URL or code into ScanSuite's SRI generator to receive a Base64-encoded hash with HTML markup.
Which algorithm is recommended for SRI?: W3C recommends SHA-384 (`sha384`) as the optimal balance of speed and security strength.
Why is crossorigin="anonymous" required for SRI?: CORS is required so browsers can inspect the cross-origin file bytes to compute the verification hash.
What happens if an SRI hash check fails?: The browser blocks execution of the script or stylesheet and logs a security error in the console.
Does SRI affect website loading speed?: No. Hashing takes less than a millisecond in browser memory during file parsing.