Log Format Parser
Paste log lines to parse, color-code, filter by severity, and analyze them instantly. Supports multiple log formats.
About This Tool
The Log Format Parser is a free browser-based tool that parses and color-codes log lines from a variety of common formats. Paste raw log output from your servers, containers, or applications, and the tool breaks each line into structured fields: timestamp, severity level, source, message, and any extra metadata.
Supported formats include Apache Combined and Apache Common access logs, Nginx access and error logs, JSON structured logs (as used by modern logging libraries like Winston, Bunyan, or Pino), syslog (RFC 3164), Docker container logs, and Kubernetes pod logs (including the klog format). The auto-detect mode tries each parser in sequence, so you can paste mixed-format logs and still get useful results.
Once parsed, you can filter by severity level (DEBUG, INFO, WARN, ERROR, FATAL) and search across all fields. The statistics panel shows severity distribution, top sources, time range, and detected formats at a glance. Color-coded severity badges make it easy to spot errors and warnings in large log dumps.
If you work with JSON log output, the JSON Formatter can help you pretty-print individual log entries. For comparing two log files side by side, try the Diff Viewer. If you need to validate your Nginx configuration, check out the Nginx Config Generator.
All processing runs entirely in your browser. No log data is ever sent to any server. This tool is safe to use with production logs that may contain sensitive information such as IP addresses, user IDs, or error details.
How to Use
- Paste your log lines into the input textarea. You can paste multiple lines at once from any source.
- Select a log format from the dropdown, or leave it on "Auto-detect" to let the tool identify the format automatically.
- Review the parsed output table below the input. Each row shows the timestamp, severity, source, message, and detected format.
- Filter by severity using the dropdown to isolate errors, warnings, or specific levels.
- Search across all parsed fields using the search box to find specific entries.
- Click Stats to view severity distribution, top sources, and time range across all parsed logs.
- Click Copy or press Ctrl+Shift+C to copy the parsed output to your clipboard.
Popular Log Parsing Examples
FAQ
Which log formats are supported?
The tool supports Apache Combined, Apache Common, Nginx (access and error), JSON structured logs, syslog (RFC 3164), Docker container logs, and Kubernetes pod logs (klog format). The auto-detect mode tries each parser in sequence to find the best match.
Can I paste logs from different formats at the same time?
Yes. When using auto-detect mode, each line is independently parsed against all supported formats. The tool picks the best matching parser for each line, so mixed-format log files work correctly.
How does severity detection work?
For formats that include an explicit level field (JSON, syslog, Kubernetes klog), the tool reads the level directly. For Apache and Nginx access logs, severity is inferred from the HTTP status code: 2xx/3xx = INFO, 4xx = WARN, 5xx = ERROR. For other formats, the tool scans the message text for keywords like ERROR, WARN, INFO, and DEBUG.
What are the color codes for each severity level?
DEBUG is displayed in gray, INFO in blue, WARN in yellow, ERROR in red, and FATAL in bold red. These colors apply to both the severity badge and the message text, making it easy to scan for problems in large log outputs.
Can I parse very large log files?
The tool processes logs in your browser, so performance depends on your device. It handles several thousand lines comfortably. For very large files (tens of thousands of lines), consider pasting a relevant subset or filtering before pasting.
Is my data safe?
Yes. All parsing runs entirely in your browser using JavaScript. No log data — including IP addresses, error messages, usernames, or any other content — is ever sent to any server. You can verify this by checking the Network tab in your browser's developer tools while using the tool.
What does the Statistics panel show?
The Statistics panel displays the distribution of severity levels with bar charts, the top 5 log sources by frequency, the time range of your logs (first and last timestamp), and a breakdown of which formats were detected across all lines.
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