CyberChef

A browser-based toolbox for encoding, decoding, inspecting and transforming data of many kinds. Operations for base64, hex, JSON, compression, hashing, certificates and encodings are chained into recipes that run entirely inside the page, and with no server component the input never leaves the browser.

Analysts, malware researchers and developers use it to unpack obfuscated payloads, parse certificates, convert timestamps and prototype transformations before scripting.

Deploying your own copy lets you examine sensitive samples and hashes on infrastructure you administer, without an external service; the static files are easy to back up.