Skip to main content

Log Level Filter

Paste any log output and instantly filter by level — DEBUG, INFO, WARN, ERROR, FATAL. Levels are auto-detected from log content. Search and grep within filtered results. Works with Log4j, Winston, Pino, Python logging, and most plain-text formats.

Filter:
Showing 16 of 16 lines
12024-01-15 08:00:01.123 INFO [main] Application starting up
22024-01-15 08:00:01.456 DEBUG [config] Loading configuration from /etc/app/config.yml
32024-01-15 08:00:01.789 INFO [db] Connecting to database at localhost:5432
42024-01-15 08:00:02.012 DEBUG [db] Connection pool initialized with 10 connections
52024-01-15 08:00:02.345 INFO [server] HTTP server listening on port 3000
62024-01-15 08:00:15.678 WARN [auth] Rate limit approaching for IP 192.168.1.100 (80/100 req/min)
72024-01-15 08:00:22.901 ERROR [db] Query timeout after 5000ms: SELECT * FROM users WHERE id=42
82024-01-15 08:00:22.902 INFO [db] Retrying query (attempt 1/3)
92024-01-15 08:00:27.234 INFO [cache] Cache miss for key user:42, fetching from DB
102024-01-15 08:00:27.567 ERROR [db] Query timeout after 5000ms: SELECT * FROM users WHERE id=42
112024-01-15 08:00:27.568 ERROR [db] Max retries exceeded for query
122024-01-15 08:00:27.890 WARN [api] Returning 503 to client — upstream unavailable
132024-01-15 08:01:00.000 DEBUG [metrics] Memory usage: 256MB / 512MB (50%)
142024-01-15 08:01:00.001 INFO [metrics] Throughput: 342 req/s, p99 latency: 48ms
152024-01-15 08:01:30.500 FATAL [app] Unhandled exception: NullPointerException at UserService.java:157
162024-01-15 08:01:30.501 FATAL [app] Shutting down due to unrecoverable error

Levels are auto-detected from log line content. Supports common formats: Log4j, Winston, Pino, Python logging, and plain text.
Share this tool: X / Twitter LinkedIn
✓ 60,000+ developers use DevPlaybook ★★★★★ 4.8 / 5 on Gumroad ✓ MIT licensed · Instant download ✓ No login required

Related Products

on Gumroad
🤖 $19

AI Prompt Engineering Toolkit

58 structured prompt templates for Claude, ChatGPT, and Gemini — organized by use case. Code Review, Debugging, Documentation, Architecture, and 10 model-specific tips. Stop writing prompts from scratch.

Buy on Gumroad →
🚀 $19

DevToolkit Starter Kit

A ready-to-deploy developer tools website with 12 built-in tools. Astro + Preact + Tailwind. Deploy to Cloudflare Pages for free. Built-in SEO, dark mode, and ad-ready layout.

Buy on Gumroad →
💬 $24

AI Developer Prompts Pack

55 battle-tested prompt templates for the workflows developers actually use: code review, debugging, architecture, documentation, and testing. Stop writing prompts from scratch.

Buy on Gumroad →

You Might Also Need

Docker Compose Generator

Generate docker-compose.yml configurations visually in your browser. Add services, ports, volumes, environment variables, and networks. Export production-ready YAML instantly. Free Docker tool.

Open free tool →

Dockerfile Generator

Interactive wizard to generate production-ready Dockerfiles for Node.js, Python, Go, Java, and Rust. Multi-stage builds, port config, custom layers.

Open free tool →

Webhook Tester

Generate realistic webhook test payloads for GitHub, Stripe, Slack, and custom services. Get a curl command to send the payload to your local endpoint. Inspect headers, payload size, and content-type.

Open free tool →

More Free Tools

Docker Compose Generator Dockerfile Generator Webhook Tester Prometheus Alert Rules Validator CI/CD Pipeline Generator Sentry DSN Config Builder Highlight.io Kubernetes Resource Calculator

Related Articles

Apr 2, 2026 · 11 min read

Microservices Observability with OpenTelemetry 2026: Tracing, Metrics, Logs

Complete guide to implementing observability in microservices using OpenTelemetry in 2026. Distributed tracing, metrics collection, structured logging, and production-ready setup with Jaeger, Prometheus, and Grafana.
Apr 2, 2026 · 10 min read

Top Kubernetes Tools for Developers 2026: Helm, k9s, Lens & More

The essential Kubernetes tools every developer needs in 2026. Hands-on guide to k9s, Lens, Helm, Kustomize, stern, kind, skaffold, and must-have kubectl plugins.
Mar 28, 2026 · 10 min read

OpenTelemetry Observability Guide 2026: Traces, Metrics & Logs

A comprehensive guide to OpenTelemetry in 2026—covering OTel architecture, traces, metrics, logs, Node.js and Python instrumentation, Jaeger, Grafana/Prometheus integration, and production cost-control strategies for backend developers.
Mar 28, 2026 · 10 min read

mise vs nvm vs volta vs fnm: Node.js Version Manager Comparison 2026

Choosing the right Node.js version manager in 2026. We compare mise, nvm, volta, and fnm on speed, cross-language support, CI/CD ergonomics, and developer experience with real benchmarks and config examples.
Mar 27, 2026 · 14 min read

Feature Flags & A/B Testing: LaunchDarkly vs Flagsmith vs Unleash 2026

A comprehensive comparison of feature flag tools in 2026. LaunchDarkly vs Flagsmith vs Unleash — pricing, SDK support, self-hosting, and when to use each.

Enjoying this tool? Get more like it.

Weekly developer tool guides, productivity playbooks & AI tricks. Free. No spam.

DevPlaybook Pro 7 days free

Unlock AI-Powered Dev Tools

  • ⚡ AI Code Review, Doc Generator & SQL Builder
  • ⚡ All premium templates & early access
  • ⚡ Member discounts on Gumroad products
Start Free Trial →

$9/mo after trial · Cancel anytime

Want the full toolkit?

Get DevPlaybook Pro

Every template, guide, boilerplate, and automation script in one bundle. 13 premium products — grab them all at once and save big.

$79
$241 separately Save $162 (67% off)
Get DevPlaybook Pro — $79 →

MIT licensed · Instant download · No subscription

See what's included → Browse all deals →