Free online debugging tool
Log analyzer and stack trace explainer
Paste an application error log to find the most useful root-cause clue, likely causes, and practical debugging steps.
Paste your log
Common Java, Spring, HTTP, database, Kubernetes, Node.js and Python errors are supported.
Keep sensitive data out. Remove customer information. Likely passwords, tokens and API keys are automatically masked before analysis.
Your explanation will appear here
We identify the error pattern, likely root cause, useful log lines, and the safest debugging steps.
Online debugging assistant
Analyze error logs and stack traces in plain English
The free log analyzer recognizes common Java, Spring Boot, HTTP, database, Kubernetes, Node.js, and Python error patterns. It highlights useful lines, explains likely causes, and suggests a safe debugging order.
Paste the relevant log
Include the exception, nested causes, and nearby application frames. Remove customer or production secrets.
Identify the root-cause clue
For one Java trace, the analyzer prioritizes the last Caused by line. Check the nearby frame against your source code.
Follow practical checks
Work through likely causes and targeted fixes instead of reading every stack frame.
Errors the log analyzer recognizes
- NullPointerException and Spring bean creation failures
- Connection refused, timeouts, HTTP 401, 403, 404, and 500
- SQL and database exceptions
- Kubernetes CrashLoopBackOff and memory failures
Java troubleshooting guides
Learn how to read a Java stack trace and find the root cause, then use the focused guide to fix NullPointerException in Java.
For failed API calls, review the API status code testing guide.
Log analyzer questions
Which log formats are supported?
The analyzer works best with plain-text application logs and stack traces from Java, Spring Boot, HTTP clients, databases, Kubernetes, Node.js, and Python.
Are pasted logs uploaded?
No. Pattern matching and explanation happen in your browser. Likely tokens, passwords, and API keys are masked before analysis, but sensitive customer data should still be removed.
Can it diagnose every production error?
No automated analyzer can see your full runtime context. Treat the result as a focused starting point and confirm it against configuration, metrics, recent deployments, and dependency health.