RawDataLength (FIX tag 95)

LengthFIX 4.4FIX 4.2FIX 5.0 SP2

RawDataLength (tag 95) is a Length field defined in FIX 4.4, FIX 4.2 and FIX 5.0 SP2. It appears in 4 message types, always optionally.

At a glance

Tag: 95
Name: RawDataLength
Datatype: Length (int)
Dialects: FIX 4.4, FIX 4.2 and FIX 5.0 SP2
Messages: 4

What the specification says

FIX 4.4

Number of bytes in raw data field.

FIX 4.2

Number of bytes in raw data field.

FIX 5.0 SP2

Number of octets in RawData(96).

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	FIX 5.0 SP2	Where in the message
Email	C	Conditional	Optional	Optional	directly on the message body
Logon	A	Conditional	Optional	Optional	directly on the message body
News	B	Conditional	Optional	Optional	directly on the message body
UserRequest	BE	Conditional	—	Optional	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

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