Log File Viewer
Paste logs and instantly filter, search, and analyze them with severity detection and statistics
About this tool
Log File Viewer takes pasted log output and color-codes every line by severity level, so you can instantly spot errors, warnings, and info messages without scanning line by line. It auto-detects common severity keywords — ERROR, WARN/WARNING, INFO, DEBUG, TRACE, FATAL, CRITICAL — and tallies them in a stats bar.
Filter chips let you toggle individual severity levels on or off, and the regex search highlights matching lines. Combine filters and regex to narrow down exactly what you need — for example, show only ERROR and WARN lines that mention "timeout".
Examples:
- Paste a stack trace with mixed ERROR/INFO lines → filter to ERROR only → see just the failing lines with their count.
- Load an Apache/NGINX access log → search
/404/→ all 404 lines highlighted among the rest.
FAQ
What log formats does this support? ›
Any text-based log format. The viewer looks for severity keywords anywhere on each line — standard levels (ERROR, WARN, INFO, DEBUG, TRACE, FATAL, CRITICAL) are recognized whether they appear as standalone words, inside brackets, or with colons. Lines without any recognized keyword are marked as "other".
Can I filter by multiple severity levels at once? ›
Yes — the filter chips work as toggles. By default all levels are shown; click a chip to hide lines of that severity, click again to show them. The "All" and "None" buttons let you reset quickly.
Does regex search affect the statistics? ›
No. The stats bar always reflects the full input. Only the output display is filtered — so you can see how many errors exist in total while searching for a specific pattern.
Is this for application logs or web server logs? ›
Both. The severity detection is keyword-based and format-agnostic, so it works with structured logging (JSON, logfmt), traditional timestamped logs, and raw stack traces equally well.