How to Format and Read Structured Logs
Use the Log Formatter to turn raw JSON logs and other structured log formats into readable, searchable output.
Tool Used
Log Formatter
Paste your raw log output
Open the Log Formatter tool. Paste your raw log output into the input field. The formatter handles multiple formats: newline-delimited JSON (one JSON object per line), nginx/Apache access logs, logfmt (key=value pairs), and plain text. You can paste multiple log lines at once — the formatter processes each line independently.
Review the auto-detected format
The formatter auto-detects the log format. Check the format indicator shown below the input field to confirm it detected the right format (JSON, nginx, logfmt, or text). If the detection is wrong, use the format selector to manually choose the correct format.
Read the formatted output
The formatted output shows each log entry with the timestamp formatted in local time, the log level colorized (ERROR in red, WARN in yellow, INFO in blue, DEBUG in grey), and all fields expanded with clear labels. For JSON logs, each field is shown on its own line with the key name. This makes it much faster to scan through logs and spot errors.
Filter by level or search for keywords
Use the level filter to show only ERROR or WARN entries and hide the noise from INFO and DEBUG messages. Use the search field to filter log lines by a specific message substring, a user ID, a request path, or any other value. The filter applies instantly as you type, narrowing the log view to only matching entries.
Find patterns across log entries
Look for repeated errors at the same timestamp — these often indicate a cascade failure. Look for errors preceded by a specific INFO event — this can reveal the sequence of events that triggered the failure. Check whether trace IDs appear across multiple entries to follow a single request through the system. The structured format makes these patterns much easier to spot than in raw log output.
All done!
You are ready to use Log Formatter like a pro.