Skill-Lite

Practical tutorials & tools for modern developers.

Developer Utilities

Tools that work,
right in your browser

A curated set of everyday dev utilities — format SQL, convert dates, switch timezones, and test APIs. No sign-up. No servers. Nothing stored.

✓ No sign-up required ✓ No data stored ✓ Works offline ✓ Open & free
All Tools
4 utilities
📄
SQL Formatter

Paste raw SQL and get beautifully formatted, readable queries in one click.

  • 14 SQL dialects — MySQL, PostgreSQL, SQLite, T-SQL, BigQuery & more
  • Keyword casing: UPPERCASE / lowercase / preserve
  • Configurable indent (2 spaces, 4 spaces, tab)
  • Paste input, copy output with one click
📅
Date Formatter

Parse any date string and convert it into any of 40+ formats instantly.

  • Auto-detects input from 19 common formats
  • Shows the date in all 40+ formats at once
  • Supports Unix timestamps and relative time
  • Today / Now quick-fill buttons
🌎
Timezone Converter

Convert any datetime between timezones and see a live world clock instantly.

  • 40+ major timezones across all world regions
  • World clock table — same moment in every zone
  • +1d / −1d badges for date boundary crossings
  • One-click swap between source and target
API Tester

Test REST API endpoints with params, auth, custom headers, and a request body.

  • All HTTP methods: GET, POST, PUT, PATCH, DELETE, HEAD
  • Auth: Bearer Token, Basic Auth, API Key
  • JSON syntax highlighting on response body
  • Response time, size, headers & download
Learn
8 tutorials · best practices
Kubernetes Tutorial

A complete, hands-on Kubernetes course — from architecture to production operations, with runnable YAML on every page.

  • 11 concept pages: Pods, Deployments, Services, Ingress & more
  • Side menu navigation with guided prev/next path
  • Copy-ready YAML manifests and kubectl commands
  • Includes a kubectl cheat sheet and debugging guide
🐳
Docker Tutorial

A practical Docker course covering images, containers, networking, volumes, Compose, and registries — from first run to production.

  • 8 pages: Images, Containers, Volumes, Networking & more
  • Side menu navigation with guided prev/next path
  • Copy-ready Dockerfiles and docker CLI commands
  • Includes a full Docker CLI cheat sheet
🌿
Spring Boot Tutorial

A comprehensive Spring Boot course covering REST APIs, DI, JPA, Security, Testing, and Actuator — from first endpoint to production-ready app.

  • 9 pages: REST API, JPA, Security, Testing & more
  • Side menu navigation with guided prev/next path
  • Copy-ready Java code with real-world patterns
  • Includes a full annotations & config cheat sheet
🐨
LangChain Tutorial

Build LLM-powered applications with LangChain — covering models, prompts, chains, memory, agents, and RAG pipelines from first call to production.

  • 8 pages: Models, Prompts, Chains, Memory, Agents, RAG & more
  • LCEL pipe-operator chains with streaming & async
  • Copy-ready Python code for OpenAI, Anthropic, Ollama
  • Full API & pattern cheat sheet
🔷
LangGraph Tutorial

Build stateful, multi-agent AI workflows with LangGraph — covering state management, cycles, checkpointing, human-in-the-loop, and streaming.

  • 8 pages: State, Nodes/Edges, Checkpointing, Multi-Agent, HITL & more
  • Supervisor pattern, subgraphs, agent handoffs with Command
  • MemorySaver & SqliteSaver for persistent, resumable sessions
  • Full API & pattern cheat sheet
📚
RAG Tutorial

Master Retrieval-Augmented Generation — from document loaders and embeddings to advanced retrieval strategies and production-ready pipelines.

  • 8 pages: Loaders, Splitters, Embeddings, Vector Stores, Retrievers & more
  • Chroma, FAISS, Pinecone, pgvector vector store integrations
  • Advanced: HyDE, re-ranking, CRAG with LangGraph
  • Full API & pattern cheat sheet
🧠
Machine Learning Tutorial

Master Machine Learning from first principles — regression, classification, neural networks, PyTorch, feature engineering, and model evaluation.

  • 8 pages: Linear Regression, Classification, Neural Networks, PyTorch & more
  • XGBoost, Random Forests, SVM — algorithm selection guide
  • scikit-learn Pipelines, cross-validation, hyperparameter search
  • Full API & pattern cheat sheet
📤
Apache Kafka Tutorial

Master event streaming with Apache Kafka — from core architecture to Kafka Streams, Kafka Connect, and Schema Registry with real production patterns.

  • 8 pages: Architecture, Producers, Consumers, Streams & more
  • KRaft mode, idempotent producers, exactly-once delivery
  • Kafka Streams windowing, joins, and interactive queries
  • Full CLI command reference and config cheat sheet

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