Log Parser & Filter
Pretty-print JSON log lines and filter by severity level.
Parsing and filtering structured logs
Production logs increasingly arrive as JSON lines with severity, trace IDs, and nested context objects. Pretty-printing and level filters help on-call engineers isolate error bursts without exporting entire files to desktop log viewers.
Filtering by severity is a first pass, not the final answer. Many stacks map custom levels or duplicate messages across services. Combine filters with timestamp correlation in your observability platform after narrowing the paste size locally.
When logs embed JSON strings inside message fields, parse and format those inner documents before diffing against known-good samples. Double-encoded JSON is a frequent source of misleading error messages during incidents.
Redact tokens, emails, and account identifiers before sharing log excerpts in tickets. Local parsing reduces the temptation to upload full log files to third-party prettifiers during stressful outages.
Reference Guide
Parse JSON log lines and filter by severity during incident triage.
- Pretty-print nested JSON inside message fields before diffing.
- Filter ERROR first, then widen to WARN if the burst is noisy.
- Correlate trace IDs in your observability platform after local narrowing.
- Redact tokens and emails from excerpts shared in tickets.
Current mode
Operation: json-log-parse
All processing runs locally in your browser. Paste input, click Run, and copy the result.
Example Input
{"level":"info","msg":"ok"}
{"level":"error","msg":"fail"}A sample loads automatically when you open this tool. Use Load Sample to reset it.