Online LOG Viewer & Log File Analyzer
Open, search, colorize, and filter server (.log, .txt) files directly in your web browser. Instant severity categorization (ERROR, WARN, INFO, DEBUG) with zero server uploads.
| 10:14:02.105 | INFO | Cluster node leader election completed: node-us-east-1a elected leader. |
| 10:14:03.220 | INFO | HTTP/2 TLS 1.3 socket listeners opened on 0.0.0.0:443. |
| 10:14:04.015 | DEBUG | Loaded 4,820 routing table rules from Redis memory cache in 1.4ms. |
| 10:14:08.540 | WARN | Slow query detected on postgresql: SELECT * FROM audit_logs WHERE timestamp > now() - interval 7 days (Duration: 840ms). |
| 10:14:12.300 | INFO | Health probe check from AWS ALB passed: 200 OK (Latency: 2ms). |
| 10:14:15.890 | ERROR | Third-party Payment Gateway webhook timed out after 5000ms: POST https://api.stripe.com/v1/webhook |
| 10:14:16.100 | INFO | Retrying webhook delivery: attempt 1 of 3 scheduled in 2000ms. |
| 10:14:22.450 | WARN | Memory heap usage reached 78% threshold (1598 MB / 2048 MB). |
| 10:14:25.670 | INFO | Garbage collector execution completed: freed 340 MB in 12ms. |
| 10:14:28.110 | DEBUG | JWT session token verified for user_id: usr_9948271 (Scope: admin). |
| 10:14:32.400 | ERROR | Uncaught TypeError: Cannot read property "id" of undefined at UserService.processLogin (/app/dist/auth.js:142:18) |
| 10:14:35.000 | INFO | Active WebSocket clients connected: 2,410. |
The Complete Guide to Server Log Inspection & Application Telemetry Analysis
Log files represent the definitive historical audit trail of computer systems, web servers (Nginx, Apache), microservices, cloud infrastructure, and database clusters. When unexpected 500 errors occur, memory usage spikes, or security breaches are investigated, software engineers and DevOps architects rely on log analysis to trace the root cause.
Opening large log dumps in basic text editors often results in freezing and visual clutter. The HiFi Toolkit Online Log Viewer automatically highlights log lines according to standardized severity classifications, allowing you to isolate errors and warnings in seconds.
Standard Log Severity Levels Explained
How to Inspect and Filter Log Files Online
- Upload Log: Click Open Log File or drag and drop any
.logor.txtfile. - Filter by Severity: Click ERROR or WARN to isolate urgent incident lines.
- Search Text: Use the live search bar to filter by user IDs, IP addresses, or error stack keywords.
