Wireshark Display Filter Syntax Helper
Wireshark Display Filter Syntax Helper: Formats valid Wireshark / tshark display filter syntax using boolean operators.
About this wireshark display filter syntax helper
Wireshark Display Filter Syntax Helper — browser-based utility.
How this tool works
Implements client-side Wireshark Display Filter Syntax Helper operations. Formats valid Wireshark / tshark display filter syntax using boolean operators specifically designed for a network security analyst constructs a wireshark display filter to capture all https traffic to a specific host.
- Protocol Message De-serialization: Parses raw DNS wire-format byte streams or HAR 1.2 JSON waterfall entries.
- Record Validation & Separation: Enforces RFC 6844 requirements that CAA authorization ('issue', 'issuewild') and reporting ('iodef') tags reside on separate records.
- Waterfall Timing Analysis: Sums network phases (blocked, dns, connect, ssl, send, wait, receive) to evaluate latency waterfalls.
- Visual Diagnostic Reporting: Renders color-coded waterfall timelines and highlights high-latency assets or missing HTTP caching headers.
Worked example
Scenario: Turn a UDP port shorthand into a display-filter text fragment.
Sample input:
Processing: Recognize the UDP prefix and decimal port, then format udp.port == 53.
Illustrative output:
Limits and verification
Rejects combined single-line CAA records that violate RFC 6844 syntax. In HAR file analysis, protects against multi-gigabyte log allocations by parsing entry streams with memory safety bounds.
Examples demonstrate an expected workflow; they do not prove every input or every branch of an external specification. Check important results with an independent source before using them for money, security, compliance, safety, or irreversible file changes.
Browser processing boundary
Tool input is processed by code running in the browser and is not intentionally sent to a CZOA processing API. The page can still request ordinary site assets, analytics, or advertising when those services are enabled. Browser extensions and managed-device software remain outside this tool's control.
Relevant references
These references govern or help explain the format, protocol, or calculation used here. Listing a reference does not claim certification or complete implementation of every optional feature.
- Wireshark Display Filter Reference Specification
- RFC 791 (Internet Protocol: IPv4)
- RFC 793 (Transmission Control Protocol)
Content owner: CZOA Tools · Last reviewed: 2026-09-15 · Review methodology
How to use it
- Enter, paste, or select your input data into the Wireshark Display Filter Syntax Helper workspace controls.
- Review available parameter fields, units, formats, or options configured for your task.
- Click the action button or observe immediate live calculations rendered in your browser runtime.
- Inspect the resulting output and any diagnostic messages, then copy or download the result if needed.
Frequently asked questions
Which local filter forms does this helper make?+
A decimal port optionally prefixed by tcp or udp becomes tcp.port == N or udp.port == N. An IPv4 value, optionally prefixed by ip or host, is validated and becomes ip.addr == address. Exact tcp, udp, dns, http, tls, and icmp become lowercase protocol names.
What input and controls are present?+
The page has one multiline Input field, Run locally, and Load sample. Empty input returns tcp.port == 443. It has no packet capture, capture-file upload, packet view, interface selector, remote Wireshark connection, or traffic inspection.
How are limits and advanced expressions handled?+
A port greater than 65535 fails, and IPv4 candidates are checked. Any other nonempty expression is returned unchanged with a note to validate it in the installed Wireshark version. This helper does not parse, prove, or execute advanced display-filter syntax.
What result does the worked example produce?+
In the worked example, the tool converted independently entered udp:53 to udp.port == 53. Network requests observed during the example had no submitted example payload. That verifies this local text branch only, not packets, example run interfaces, traffic, or full Wireshark validation.