Enter your text and the SHA-512 digest appears immediately. Everything runs locally, so your input never leaves the browser.
128 hexadecimal characters, or 512 bits.
Both are secure members of SHA-2. SHA-512 has a larger digest and is often faster on 64-bit CPUs, but SHA-256 is sufficient for most uses.
No — it is a one-way function. You cannot recover the original input from the digest.