A Free Developer Tool from ZagTrader
This FIX log parser is a complimentary tool for the financial community. Analyze your FIX messages quickly and securely.
Your data is safe. All processing happens entirely in your browser and no data is ever transmitted to our servers.
Paste FIX Log
| Time | Sender | Target | Message | Client Order ID |
|---|
| Tag | Value | Description |
|---|
How to Use This FIX Decoder
- Paste Your Log: Copy your raw FIX log data, including multiple lines if necessary, into the text area above.
- Process: Click the "Process" button. The tool will instantly parse the log.
- Analyze Timeline: View a chronological summary of all messages in the "Timeline" view. Click any message to see its details.
- Inspect Details: The "Details" view shows a tag-by-tag breakdown of the selected message, with descriptions and color-coded values for clarity.
Understanding the FIX Protocol
The Financial Information eXchange (FIX) protocol is the messaging standard for the global financial industry. It provides a universal format for real-time communication for securities transactions and markets, from pre-trade indications to trade execution and post-trade reporting.
Message Structure
At its core, a FIX message is a sequence of tag=value pairs separated by a special, non-printable Start of Header (SOH) delimiter (ASCII value 0x01), often represented as | or ^ in logs for readability. Each tag is a unique number that represents a specific data field.
Header, Body, and Trailer
Every FIX message is divided into three parts:
- Header: The header always starts the message. It includes essential tags like
8=BeginString(the FIX version),9=BodyLength(the character count of the message body), and35=MsgType(which defines the message's purpose). - Body: This is the main part of the message and contains the business-level information. The tags in the body vary depending on the message type (
35=MsgType). - Trailer: The trailer always ends the message. It contains the
10=CheckSumtag, which is a simple checksum used to verify message integrity.
Common Message Types
While there are hundreds of message types, a few are fundamental to most FIX sessions:
35=A(Logon): Used to initiate a FIX session and authenticate a user.35=0(Heartbeat): Sent periodically to monitor the health and status of the connection.35=D(New Order - Single): The primary message for placing a new order to buy or sell a security.35=8(Execution Report): Used to confirm the status of an order. It can indicate that an order is new, partially filled, filled, canceled, or rejected.35=5(Logout): Used to gracefully terminate a FIX session.