RawDataLength (FIX tag 95)

LengthFIX 4.4FIX 4.2

RawDataLength (tag 95) is a Length field defined in FIX 4.4 and FIX 4.2. It appears in 4 message types, always optionally.

At a glance

Tag: 95
Name: RawDataLength
Datatype: Length (int)
Dialects: FIX 4.4 and FIX 4.2
Messages: 4

What the specification says

Number of bytes in raw data field.

Descriptions are quoted from the FIX Orchestra sources under the Apache 2.0 licence.

A real message using tag 95

Logon · FIX 4.4

Tag	Field	Wire value	Meaning
8	BeginString	FIX.4.4
9	BodyLength	79
35	MsgType	A	Logon
49	SenderCompID	BOARTEAM
56	TargetCompID	COUNTERPARTY
34	MsgSeqNum	2
52	SendingTime	20240101-12:00:00.000
98	EncryptMethod	0	None / other
108	HeartBtInt	1
95	RawDataLength	7
10	CheckSum	144

Edit and decode it yourself

Shown with | separators for readability. On the wire FIX uses SOH (0x01), an invisible control byte — and because BodyLength and CheckSum are computed over the actual bytes, the two forms have different checksums. Both are valid and both decode here.

Open in the full decoder →

Generated from the FIX 4.4 dictionary and verified at build time: it parses and validates with no issues. Open the decoder to try your own message.

Where tag 95 appears

Requiredness is a property of the message, not of the field: the same tag can be optional in one message and conditionally required in another.

Message	MsgType	FIX 4.4	FIX 4.2	Where in the message
Email	C	Conditional	Optional	directly on the message body
Logon	A	Conditional	Optional	directly on the message body
News	B	Conditional	Optional	directly on the message body
UserRequest	BE	Conditional	—	directly on the message body

Wire format

A byte count for the length-prefixed field that follows it. Count bytes, not characters — a multi-byte UTF-8 value makes the two differ. @boarteam/fix parses the value as a number and reports parse/invalid-int when it does not lex as one; the raw string is kept either way.

Read tag 95 in TypeScript

decode.tsts

import { createFixEngine } from "@boarteam/fix";import { dictionary } from "@boarteam/fix-dict-fix44";const fix = createFixEngine(dictionary);const { message, issues } = fix.parse(raw);const field = message.fields[95];field?.name;   // "RawDataLength"field?.raw;    // the verbatim wire stringfield?.value;  // coerced to a number

Other Length fields

Decode this in your own code

The same engine that produced the decoded example above is an Apache-2.0 npm package with zero runtime dependencies. It runs in Node and in the browser, and parse() returns problems as data instead of throwing.

npm i @boarteam/fix @boarteam/fix-dict-fix44

Try the decoder Source on GitHub