Group repeated log errors
Dynamic timestamps, request IDs, ports, memory addresses and changing numbers are normalized to reveal recurring failure patterns.
Private browser-based developer tool
Free online log analyzer and error grouper
Paste server, Docker, Kubernetes or application logs to group repeated errors, inspect severity and create an incident report. Analysis runs locally—your log data never leaves this browser.
Free · No account or email · Processed entirely on your device
Plain text and JSONL
Automatic secret redaction
Markdown export
Local processing
18 repeated errors grouped
Online log analysis tool
Find the errors hiding in noisy logs
LogLens identifies severity, normalizes changing values and groups repeated messages so you can focus on distinct failure patterns.
Runs locally in your browser
Paste logs or load the sample to begin.
Analysis results
0Non-empty lines
0Errors / critical
0Warnings
0Distinct patterns
0%Noise reduction
Severity distribution
Repeated error and message groups
Log investigation features
From raw output to actionable clues
Use the analyzer for first-pass incident triage before opening a full observability platform or sharing sensitive output.
Separate errors from warnings
Quickly compare error, warning and informational lines without manually searching a long Docker or application log file.
Create an incident handoff
Export a practical Markdown summary containing metrics, dominant patterns, redacted examples and an investigation checklist.
How to analyze a log file
Three steps from logs to incident report
No installation, command-line setup or account is required.
1
Paste or drop your logs
Use plain text, JSONL or output copied from Docker Compose, kubectl, Nginx, Node.js, Python or another application.
2
Review grouped errors
Compare severity totals and inspect the most frequent normalized messages. Secret masking remains enabled by default.
3
Download the report
Save the Markdown file and attach it to an issue, incident channel, pull request or engineering handoff.
Practical log troubleshooting examples
Patterns worth checking first
These common examples show what a grouped message can mean and the next verification step to take.
Docker Compose port conflict
Meaning: Another process or container is already bound to the requested host port. Check active containers and host listeners, then change or release the port.
ERROR: Bind for 0.0.0.0:5432 failed: port is already allocated docker compose ps lsof -i :5432
Connection refused errors
Meaning: The target resolved, but nothing accepted the connection. Verify service startup, hostname, port mapping and container network membership.
connect ECONNREFUSED 172.18.0.3:6379 ConnectionError: [Errno 111] docker compose logs redis docker compose exec app getent hosts redis
Kubernetes Service mismatch
Meaning: A Service may have no matching ready endpoint. Compare its selector with pod labels, then inspect readiness and targetPort.
upstream connect error no endpoints available for service kubectl get endpoints kubectl describe service kubectl get pods --show-labels
Frequently asked questions
Online log analyzer FAQ
Privacy, supported formats, error grouping and report export explained.
Are my logs uploaded to a server?
No. Parsing, grouping, redaction and report generation run locally in your browser. Avoid pasting sensitive information into any tool unless your organization permits it.
Which log formats can LogLens analyze?
LogLens accepts plain-text and JSON-line logs from applications, servers, Docker, Docker Compose, Kubernetes, Nginx and common command-line tools. It analyzes each non-empty line independently.
How does repeated error grouping work?
The analyzer removes common timestamp and severity prefixes, then normalizes UUIDs, IP addresses, hexadecimal values and changing numbers. Messages with the same remaining pattern are grouped together.
Does secret redaction modify my original input?
No. Redaction applies only to displayed and downloaded examples. Your textarea content remains unchanged so you can repeat the analysis with different settings.
Can I analyze Docker Compose and Kubernetes logs?
Yes. Paste output from commands such as docker compose logs or kubectl logs. LogLens can group repeated port conflicts, connection failures, crash loops and application exceptions.
What is included in the Markdown incident report?
The report contains the analysis date, line and severity totals, the most frequent normalized patterns, redacted examples and a reusable investigation checklist. If you have not run an analysis, the button downloads a sample incident template.
Keep a useful incident artifact
Download your log analysis as a Markdown report
Run the analyzer first to include your grouped results, or download the ready-to-fill sample template immediately.
Free · No registration or email · Generated locally on your device