Grok Debugger
Parse and debug Grok patterns against log data.
Frequently Asked Questions
What is a Grok debugger?
A Grok debugger tests and debugs Grok patterns against sample log data. Grok is a pattern matching syntax commonly used in Logstash and Elasticsearch for parsing unstructured log lines into structured data.
How do I use the Grok debugger?
Enter your Grok pattern in the pattern field, paste a sample log line in the data field, and the tool shows the parsed output with matched fields and their values.
What are Grok patterns used for?
Grok patterns are used in log processing pipelines (like ELK Stack) to extract structured fields from unstructured log lines, such as IP addresses, timestamps, HTTP methods, and status codes.
Does it support custom Grok patterns?
You can combine the built-in patterns (like %{IP} or %{TIMESTAMP_ISO8601}) with your own regular expressions, including named groups such as (?<id>\d+). Add :int or :float to convert a value (%{INT:status:int}) and use [outer][inner] for nested fields.
Is this tool free?
Yes, ToolDock's Grok debugger is completely free and requires no signup. Pattern matching runs in your browser; only the optional AI pattern generator sends your sample log line to ToolDock's server.