Toggle TCP flags to calculate byte values, or enter a hex/decimal value to see which flags are set. Useful for packet analysis, firewall rules, and network debugging.
| Bit | Flag | Full Name | Description |
|---|---|---|---|
| 7 | CWR | Congestion Window Reduced | Sender reduced its congestion window (ECN response) |
| 6 | ECE | ECN-Echo | Peer supports ECN / congestion experienced |
| 5 | URG | Urgent | Urgent pointer field is valid |
| 4 | ACK | Acknowledgment | Acknowledgment number field is valid |
| 3 | PSH | Push | Push buffered data to the application |
| 2 | RST | Reset | Reset the connection |
| 1 | SYN | Synchronize | Synchronize sequence numbers (start connection) |
| 0 | FIN | Finish | No more data from sender (close connection) |