Hex Byte Inspector
Paste a hex, Base64 or text value to see its byte / bit / hex-char length, the same bytes in hex, Base64 and text, and which common key, hash and signature sizes match. Runs in your browser; nothing is uploaded.
About this tool
The Hex Byte Inspector reads a value you paste — as hex, Base64, or plain
text — and reports everything you usually reach for a calculator or a xxd
pipe to work out:
- its length as bytes, bits and hex characters;
- the same bytes shown in hex (grouped for readability), Base64, and printable text;
- and, optionally, which common cryptographic value sizes match that byte length — hash digests, AES/ChaCha keys, Ed25519/secp256k1 keys and signatures, and nonces/IVs.
It runs entirely in your browser: the value you paste never leaves your machine, which matters when the "value" is a private key, a token, or a session secret.
Worked example
Paste Hi with Read input as set to Text and you get:
Bytes: 2
Bits: 16
Hex chars: 4
Hex: 4869
Base64: SGk=
Text: "Hi"
Now paste a 64-hex-character SHA-256 digest such as
9f86d081884c7d659a2feaa0c55ad015a3bf4f1b2b0b822cd15d6c15b0f00a08 as Hex with
Show matching crypto sizes on, and the report ends with:
Bytes: 32
Bits: 256
Hex chars: 64
...
Matches (common 32-byte / 256-bit values):
- SHA-256 / SHA3-256 / BLAKE2s digest
- AES-256 or ChaCha20 key
- Ed25519 public or private key
- secp256k1 or NIST P-256 private key
That last block is the quick "what is this 32-byte blob likely to be?" answer.
Options and limits
- Read input as —
hex(the default),base64, ortext. The hex reader is tolerant: ASCII whitespace,:-,_delimiters and per-byte0x/\xprefixes are stripped before decoding, so pasting0x48 0x69or48:69works. - Hex group size — how many bytes go in each space-separated group of the Hex
line;
0prints it continuous. It's clamped to the range0–64. - Uppercase hex and Show matching crypto sizes are simple on/off toggles.
- A hex value must decode to a whole number of bytes (an even count of hex digits) and Base64 must be a valid sequence, otherwise the tool explains what's wrong instead of guessing.
FAQ
What counts as one byte, and how do bytes, bits and hex characters relate?
One byte is 8 bits, and it's written as exactly 2 hex characters
(00–ff). So a 32-byte value is 256 bits and 64 hex characters — the three
numbers on the first lines of the report are just the same length in different
units.
My hex has spaces, colons or a 0x prefix — do I need to clean it first?
No. With Read input as set to Hex, the tool ignores ASCII whitespace and
the : - , _ delimiters, and it strips per-byte 0x and \x prefixes. So
de ad be ef, de:ad:be:ef and 0xde 0xad 0xbe 0xef all decode to the same four
bytes. It only complains if a non-hex character remains or the digit count is odd.
How does it decide which cryptographic values "match"?
Purely by byte length — it never inspects or validates the content. A 32-byte value is the size of a SHA-256 digest, an AES-256 key, and an Ed25519 key, so all of those are listed as possibilities. It's a hint to narrow down what an unknown blob might be, not a claim that your value actually is any of them.
Is my data sent anywhere?
No. The inspector is compiled to WebAssembly and runs locally in your browser, so the value you paste — including private keys or secrets — stays on your machine.
Developer & Automation Access
Run it from the terminal
Same engine as this page, headless — via the gizza CLI:
gizza tool hex-byte-inspector "Paste hex, Base64 or text…"New to the CLI? Get gizza →
Open it by URL
Pre-fill and auto-run this tool with query parameters — the names match the API/CLI:
https://gizza.ai/tools/hex-byte-inspector/?input=Paste%20hex%2C%20Base64%20or%20text%E2%80%A6&input_format=hex&group_size=4&uppercase=true&interpret=trueMachine-readable descriptor: tool.json — title + parameters JSON Schema for agents.