Hash
SHA-family digests are computed with the browser's built-in WebCrypto — no network needed, and the content never leaves your device.
About MD5
Browser-native WebCrypto MD5 not offered(it's now considered insecure, and browser vendors removed support for it). If you need MD5, you have to bring in a third-party implementation; this site deliberately doesn't, to stay "zero third-party code".