About JA4Server Fingerprint
Generates a JA4Server Fingerprint (JA4S) to help identify TLS servers or sessions based on hashing together values from the Server Hello. Input: A hex stream of the TLS or QUIC Server Hello packet application layer.
Input: text. Output: text.
Format reference: JA4Server Fingerprint background and specification
Example
Use “Try example” to load this public sample and its settings, then run it.
Settings used in this example
| Parameter | Example value | Input and choices |
|---|---|---|
| Input format | Hex | Hex, Base64, Raw |
| Output format | JA4S | JA4S, JA4S Raw, Both |
Input
16030300640200006003035f0236c07f47bfb12dc2da706ecb3fe7f9eeac9968cc2ddf444f574e4752440120b89ff1ab695278c69b8a73f76242ef755e0b13dc6d459aaaa784fec9c2dfce34cca900001800000000ff01000100000b00020100001000050003026832
Result
t1204h2_cca9_1428ce7b4018
Parameters
| Parameter | Default value | Input and choices |
|---|---|---|
| Input format | Hex | Hex, Base64, Raw |
| Output format | JA4S | JA4S, JA4S Raw, Both |
Before interpreting the result
Protocol parsers need the correct byte representation and framing. HTTP Request and DNS over HTTPS contact remote services only when you run them; browser network and CORS restrictions still apply.
How to use this page
- Paste your input or open a local file.
- Adjust tool options if needed, then choose Run tool.
- Copy the result or download the original output bytes.
Inputs and results are not added to the public catalogue or saved in the URL. Processing happens in your browser; HTTP Request and DNS over HTTPS send the requests you explicitly run. Files up to 128 MiB can be opened; decompression and image tools may have smaller processing limits. Large results have a shortened preview. Text and HTML downloads use UTF-8; binary downloads preserve output bytes. Pasted text follows browser newline handling; open a file when exact input bytes matter.