TCP Header Analyzer

SanchitGurukul Networking Tools

TCP Header Analyzer

Paste raw TCP header bytes to decode ports, sequence and acknowledgement numbers, header length, flags, window size, checksum, urgent pointer, and TCP options.

Raw TCP header

Enter at least 20 bytes. Spaces, colons, hyphens, line breaks and an optional 0x prefix are accepted.

Important: A TCP checksum cannot be independently verified from the TCP header alone. Verification also requires the IP pseudo-header and TCP payload.

Header summary

Source Port—
Destination Port—
Header Length—
Active Flags—
Enter a TCP header and select Analyze Header.

Decoded fields

FieldBytes / BitsValueExplanation
No header analyzed yet.

TCP flags

TCP options

Options will appear when the data offset is greater than 5.

How to use this analyzer

  1. Copy only the TCP header bytes from a packet capture or protocol exercise.
  2. Paste the hexadecimal bytes above and select Analyze Header.
  3. Compare the decoded values with Wireshark, tcpdump, or your lab worksheet.

Privacy: all packet data is processed locally in your browser and is never transmitted or saved.

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