Online FIX Log Parser – Free Instant FIX Message Analyzer
FIX Doctor is a free, instant online FIX log parser that analyzes FIX protocol messages to detect errors, sequence gaps, missing mandatory fields, and structural issues. No installation or registration required.
Key Features
Instant Error Detection
Automatically identifies missing mandatory fields, invalid enum values, sequence gaps, and malformed messages.
Sequence Gap Analysis
Detects sequence number gaps, duplicates, and out-of-order messages in your FIX session logs.
Message Timeline
Visual timeline showing Logon, NewOrderSingle, ExecutionReport, Reject, and other message types.
Tag Expansion
Human-readable tag names (e.g., "Symbol" instead of "55") for easier log analysis.
Supported File Types
Upload plain text FIX logs in any of these formats:
- .txt – Plain text FIX logs
- .log – Standard log files
- .fix – FIX-specific log files
- .msg – Message files
- .dat – Data files containing FIX messages
How It Works
- Upload: Drag and drop your FIX log file or click to browse
- Parse: FIX Doctor automatically detects delimiters (SOH, pipe, semicolon) and parses all messages
- Analyze: The system checks for errors, sequence gaps, missing fields, and structural issues
- View Results: See a detailed summary with top errors, timeline, and message table
What FIX Doctor Detects
- Missing mandatory fields (ClOrdID, Side, Symbol, OrderQty, etc.)
- Invalid enum values (e.g., Side=99 when only 1 or 2 are valid)
- Sequence number gaps and duplicates
- Missing Price for Limit orders (OrdType=2)
- Session-level rejects (35=3) with RefTagID analysis
- Timestamp gaps and ordering issues
- Malformed tag=value pairs
Ready to Analyze Your FIX Logs?
Upload your FIX protocol logs now for instant error detection and detailed diagnostics. Free, fast, and no registration required.
Upload FIX Log Now