None of these tasks is difficult, which is exactly the problem: each one is small enough to interrupt what you were doing and large enough to cost you ten minutes if you get it wrong by hand. Every tool here does one job, does it immediately, and shows you what it did. All of them run entirely inside the browser tab, so a payload, a key or a piece of user data never leaves the machine it was typed on.
Data formats
Identifiers and secrets
Time and colour
Why a local tool beats a service
The usual reason to reach for a web tool instead of writing a one-liner is speed, and the usual reason to hesitate is that it means pasting whatever you are working on into somebody else's website. That hesitation is well founded. A payload you are debugging may contain a session token, a query may contain a customer's email address, and a password field is by definition the last thing that should be sent anywhere.
Everything on this page sidesteps the problem rather than asking you to trust a promise about it. The tools are static files: the browser downloads a little JavaScript once and then does the work locally. There is no endpoint for the data to be posted to, which means there is nothing to log, nothing to retain and nothing to leak if the site is ever compromised. Base64, hashing, UUID generation and password generation use the platform's own Web Crypto implementations — the same code that secures HTTPS — and the rest is plain arithmetic.
The practical upshot is that you can paste production data into these tools without thinking about it first, which is the only way a utility like this is genuinely useful. The counterpart is that nothing is stored for you either: close the tab and the working state is gone, by design.