Packet diagrams (packetdiag)

Compatible with packetdiag

Protocol packet layouts in a column-based DSL — write `0-15: source port` `16-31: destination port` and every bit-field renders with the correct width. Ideal for RFC-style protocol documentation; complementary to bytefield-svg.

Templates

Source language

plaintext

Workstation

Studio

Engine id

packetdiag

Open in Studio Upstream docs

In the same space

Most users come to Packet diagrams (packetdiag) from Hand-drawn RFC packet layouts. Glyph runs this engine in the browser — no install, shareable via URL, exportable to PNG / SVG / PDF / source.

Syntax at a glance

packetdiag {
  0-15: Source port
  16-31: Destination port
  32-47: Length
}

Paste this in the Studio code pane to see Packet diagrams (packetdiag) render live. The full grammar is at the upstream-docs link above.

Sample templates

All 8 →

architecture

UDP header

Classic 64-bit UDP header — source port, destination port, length, checksum. Bit-positions enforced.

architecture

TCP header — bit fields

Bit-precise TCP header. Compare with the bytefield-svg version for two takes on the same layout.

architecture

ICMP echo packet

Ping packet — Type / Code / Checksum / Identifier / Sequence number + payload.

data

packetdiag — IPv4 header

Bit-accurate IPv4 header layout.

data

packetdiag — TCP header

Standard TCP segment header.

data

packetdiag — UDP datagram

Tiny UDP header.

Engine reference: packetdiag · ← Browse all engines · Quick-start guide