Decoder Toolbox

The everyday conversions in one place — for triage, log digging, and CTF nights.

Runs entirely in your browser — your input is never transmitted anywhere.

How it works

Every operation uses standard browser APIs — atob/btoa with proper UTF-8 handling, encodeURIComponent, and WebCrypto digest() for hashes. MD5 is deliberately absent: it's broken for anything security-relevant, and WebCrypto rightly doesn't ship it.

FAQ

Why does Base64-decoding random data fail?

Not everything that looks Base64 is Base64 — and valid Base64 may decode to binary that isn't printable text. The tool shows a hex preview when the output isn't valid UTF-8.

Epoch in seconds or milliseconds?

Both — the converter auto-detects: 10 digits ≈ seconds, 13 ≈ milliseconds. It also accepts an ISO date and gives you the epoch back.