Grok Pattern Tester & Nginx Log Regex Generator
Test and debug Grok expressions against real production logs. Generate parsed JSON tokens, compile standard regular expressions, and validate configurations for Vector, Fluent Bit, and Logstash.
A Grok pattern tester matches raw, unstructured server log lines against reusable named regular expressions—converting arbitrary strings into structured JSON key-value pairs. By compiling standard syntax like %{IPORHOST:client_ip} and %{NUMBER:status_code}, observability engineers validate Logstash, Vector, and Fluent Bit parsing pipelines in real time before deploying configurations to production log collectors.
Interactive In-Browser Log Parser & Token Extractor
Select an enterprise log format or input custom log lines and Grok patterns.
Real-Time Field Extractor Tokens
client_ip • status_code • request_path • duration_msCommon Grok Patterns Cheat Sheet
Standard pre-compiled Grok definitions used in Logstash, Vector VRL, Fluent Bit, and Datadog pipelines.
| Grok Pattern | Regex Equivalent | Sample Log Match | Usage Example | Action |
|---|---|---|---|---|
| %{IPORHOST} | (?:IP|HOSTNAME) | 192.168.1.105, api.domain.com | %{IPORHOST:client_ip} | |
| %{NUMBER} | (?:[+-]?(?:[0-9]+(?:\.[0-9]+)?)) | 200, 4528, 0.042 | %{NUMBER:status_code:int} | |
| %{URIPATH} | (?:/[A-Za-z0-9$.+!*'(),~:;=@#%_\-]+)+ | /api/v2/products/4192 | %{URIPATH:request_path} | |
| %{TIMESTAMP_ISO8601} | (?:[0-9]{4}-[0-9]{2}-[0-9]{2}T...) | 2026-09-06T14:40:12.451Z | %{TIMESTAMP_ISO8601:timestamp} | |
| %{HTTPDATE} | DD/Mon/YYYY:HH:MM:SS TZ | 06/Sep/2026:14:22:18 +0000 | %{HTTPDATE:timestamp} | |
| %{WORD} | \w+ | GET, POST, error, stdout | %{WORD:verb} | |
| %{DATA} | .*? (Non-greedy) | Mozilla/5.0, arbitrary text | %{DATA:user_agent} | |
| %{GREEDYDATA} | .* (Greedy match to EOL) | Remainder of message payload | %{GREEDYDATA:message} |
Observability Ingestion Guides & Benchmarks
Deep-dive guides for production Nginx configurations, AWS Load Balancer telemetry, and high-throughput collector engines.
Nginx Access Log Grok Pattern Generator
Standard combined vs custom microservice format generator. Includes upstream latency, gzip ratios, and Vector VRL code snippets.
AWS ALB Access Log Regex Parser
Full 29-field AWS Application Load Balancer specification. Includes Amazon Athena DDL, CloudWatch Log Insights queries, and error handling.
Vector vs Fluent Bit Benchmark
Empirical benchmark measuring EPS throughput, SIMD JSON acceleration, memory footprint (RSS), and backpressure under sustained load.