Local-first · Free · Open source
Free online log file analyzer & viewer
Open, search and filter large log files directly in your browser. No upload, no account and no server-side import.
Open a log file · Support this open-source project
Analyze the log you have, without sending it away
Log Voyager is a free log file analyzer online, but the analysis itself stays on your machine. Open an application, web-server, container or system log and get a clear first view before choosing a larger observability workflow.
Search for an exception, request ID, status code, service name or timestamp. Use text search, case matching, regular expressions and filters to reduce a noisy export while keeping the original file unchanged.
Common investigation tasks
- Debug production exceptions
- Review Nginx and Apache requests
- Inspect Docker container output
- Trace JSON and JSONL application events
- Find request IDs in API logs
- Rebuild a syslog incident timeline
Inspect the formats you already use
Focused guides for structured application output, web-server access files, container exports and system logs.
- JSON log viewer for files that stay private - Open JSON, JSONL and NDJSON log files in your browser. Search structured logs locally, format objects and keep production data on your device.
- Open large log files without loading them all into RAM - Open and search multi-gigabyte log files in your browser without uploading them. Chunked reading, regex filters, bookmarks and local processing.
- Nginx log analyzer for access and error files - Inspect Nginx access and error logs locally. Search 4xx/5xx responses, upstream timeouts, request paths and client IPs without uploading logs.
- Apache log viewer for access and error investigations - Open Apache access.log and error.log files locally. Search status codes, modules, request paths and client addresses without uploading server logs.
- Docker log viewer for container output and JSON files - Inspect Docker JSON-file and Compose log exports locally. Search container output, stack traces, service prefixes and timestamps without uploads.
- Syslog viewer for local system-log investigations - Open syslog, messages and exported journal logs locally. Search hosts, services, priorities and incident timestamps without uploading system data.
Private by design
File reading, search, filters, bookmarks and export run in the browser. The viewer reads small file slices around the current position instead of uploading a complete production log.
Frequently asked questions
Are log files uploaded?
No. Selected files stay on your device.
Is Log Voyager free?
Yes. It is MIT-licensed; optional Ko-fi contributions support maintenance.