📖 What is Log Parser?
Log Parser helps you analyze log file content. Paste logs and filter by level (ERROR, WARN, INFO), search for patterns, extract timestamps, count occurrences and isolate specific entries. Use it to debug production issues, analyze error patterns, or extract specific log entries from large files. Everything runs in your browser — your logs are never uploaded.
💡 Example
Input
2026-06-10 09:15:23 ERROR Database connection timeout
2026-06-10 09:15:24 INFO Retrying connection
2026-06-10 09:15:25 ERROR Connection refused
Output
Filtered (ERROR only): 2 entries
- Database connection timeout
- Connection refused
🛠️ Common Use Cases
- Filtering large log files by error level (ERROR, WARN, INFO, DEBUG)
- Searching for specific error patterns or keywords
- Counting error occurrences to identify the most common issues
- Extracting timestamped entries from a specific time range
- Analyzing log output from CI/CD pipelines or deployments
📝 Log Levels
FATAL/CRITICAL — application cannot continueERROR — an operation failed but the application continuesWARN — something unexpected, but not necessarily a failureINFO — normal operational messagesDEBUG — detailed diagnostic informationTRACE — most verbose, step-by-step execution
⚠️ Common Mistakes
- Searching for exact strings — use pattern matching. Error messages often contain variable data (IDs, timestamps).
- Ignoring timestamps — correlate errors by time to find root causes and cascading failures
- Missing context — errors often need the surrounding INFO/DEBUG lines to understand what happened
❓ Frequently Asked Questions
Can I filter by log level? ▾
Yes — filter by ERROR, WARN, INFO or DEBUG to isolate entries at a specific severity level.
How large a log file can I analyze? ▾
This browser-based tool handles files up to a few MB comfortably. For very large files (100MB+), use command-line tools like grep, awk or dedicated log management tools.
Can I use regex to search? ▾
The search supports keyword matching. For regex-level pattern matching, consider using grep or awk on the command line.
Is my data private? ▾
Yes — all processing runs entirely in your browser. Your data is never sent to any server.
Is this tool free? ▾
Completely free — no login, no usage limits, works offline once loaded.
Yes — completely free, no login required, no usage limits.
Is my data private? ▾
Yes — all processing runs in your browser. Your data is never sent to any server.
Does it work offline? ▾
Yes — once the page is loaded, the tool works without an internet connection.