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Packet AnalysisLOCALRuns in your browser

TCP Decoder

Decode TCP ports, sequence numbers, flags, window, options, and payload from a raw segment.

This tool handles input and primary processing in your browser and is designed not to send the input to QuickKit’s server.

Decoded fields

Remaining payload

How it works

Paste a TCP segment beginning at the source port. Data offset and option bounds are validated. The checksum is displayed but not declared valid or invalid because a TCP checksum requires the IPv4/IPv6 pseudo-header, which this standalone input does not provide.