UDP Header Stripper
Paste a raw UDP datagram as hex and strip the fixed 8-byte UDP header to get the encapsulated application payload as hex, plus the source and destination ports, the length and checksum fields. The UDP Length field is honored to drop trailing padding. Spaces, colons, dashes, dots, and a 0x prefix are ignored. Runs in your browser; nothing is uploaded.
About this tool
UDP Header Stripper removes the fixed 8-byte UDP header from a raw UDP datagram, given as a hex string, and returns the encapsulated payload — the application data (e.g. a DNS message, a QUIC packet, RTP media) that UDP carries.
- Fixed 8-byte header. A UDP header is always exactly eight bytes — source port, destination port, length, and checksum, two bytes each (RFC 768). Those bytes are removed and the rest is the payload.
- Decodes the header fields. The source port, destination port, the
Length field (header + data), and the Checksum (where
0x0000means "not computed") are shown alongside the payload. - Honors the Length field. When the UDP Length field is present and consistent, it is used to trim any trailing link-layer padding (an Ethernet frame pads small packets to 60 bytes), so you get exactly the UDP payload.
- Returns hex. The payload is emitted as a lowercase hex string with no separators, ready to paste into another decoder.
The header is the UDP portion of a datagram — the part before the application
data. Stripping it leaves what the application sees. Input may use spaces,
colons, dashes, dots, or a leading 0x; they are all ignored.
Example
00 35 a1 b2 00 0c 12 34 de ad be ef
└src─┘ └dst─┘ └len┘ └csum┘ └─ payload ─┘
└──────── UDP header (8 bytes) ───────┘
The 8-byte header is removed and the payload deadbeef is returned, from a
datagram with source port 53 and destination port 41394.
Common uses
- Pull the application payload out of a captured UDP datagram to feed a protocol decoder (DNS, DHCP, RTP, QUIC, …).
- Strip UDP framing and padding to isolate the exact payload bytes.
- Read the source/destination ports and length by hand from raw bytes.
FAQ
Can I paste a whole Ethernet or IP packet?
No — the input must start at the first byte of the UDP header. If you paste a full frame, the Ethernet/IP header bytes would be misread as ports and length. From a capture, copy the bytes starting at the UDP layer (in Wireshark: right-click the UDP layer → Copy → "…as a Hex Stream").
Why is the payload shorter than the bytes I pasted?
The UDP Length field (header + data) is honored when it's consistent with the input: anything beyond it is treated as trailing link-layer padding and dropped. Ethernet pads small frames to 60 bytes, so captured datagrams often carry a few padding bytes that are not part of the payload.
What does a checksum of 0x0000 mean?
That the sender didn't compute one. Over IPv4 the UDP checksum is optional and
0x0000 explicitly means "not computed" (RFC 768) — the tool reports it as such
rather than flagging an error.
What hex formats are accepted?
Pretty much anything a capture tool exports: spaces, colons, dashes, dots, and a
leading 0x are all ignored, so 00 35 a1 b2 …, 00:35:a1:b2:… and
0x0035a1b2… parse identically. The datagram must be at least 8 bytes (the fixed
UDP header size).
Developer & Automation Access
Run it from the terminal
Same engine as this page, headless — via the gizza CLI:
gizza tool strip-udp-header "0035 a1b2 000c 1234 de ad be ef"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/strip-udp-header/?datagram=0035%20a1b2%20000c%201234%20de%20ad%20be%20efMachine-readable descriptor: tool.json — title + parameters JSON Schema for agents.