Free Online Developer Tools & Utilities
A growing collection of fast, in-browser utilities for web engineers. Convert SVG, generate types, design CSS, and preview social meta: all in one place, all client-side, all free.
SLO & Error Budget Multi-Window Burn-Rate Calculator
Google SRE Multiwindow Multi-Burn-Rate calculator for Service Level Objectives. Calculate allowed downtime, budget exhaustion time, and export Prometheus Alertmanager YAML & Grafana PromQL queries.
PgBouncer & PostgreSQL Connection Pool Calculator
Model PostgreSQL connection scaling across microservices. Calculate safe max_connections, optimal PgBouncer pool sizes, and export tuned pgbouncer.ini, postgresql.conf, and Kubernetes manifests.
Model Context Protocol (MCP) Configurator
Configure and validate Model Context Protocol (MCP) servers with stdio and SSE transports. Export ready-to-run configurations for Claude Desktop, Claude Code CLI, Cursor, and TypeScript/Python SDKs.
LLM Token & API Pricing Calculator
Model monthly token economics across Gemini 2.5 Flash, DeepSeek R1/V3, Claude 3.5 Sonnet, and GPT-4o with prompt caching discounts, token counter, and markdown export.
Docker Compose to Kubernetes Converter
Convert Docker Compose v2/v3 files to production-ready Kubernetes Deployments, Services, ConfigMaps, PVCs, and Ingress manifests with custom replicas, probes, and resource limits.
cURL to Fetch, Python & Go Converter
Convert cURL commands to JavaScript Fetch, Axios, Python Requests, async HTTPX, Go net/http, and Rust. Features 100% client-side privacy and secret redaction.
SQLite Production PRAGMA Configurator
Fine-tune WAL mode, busy timeout, cache size, and mmap memory settings. Generate production-ready connection code for Python, Node.js, Go, and Rust.
SQL Query Optimizer & Index Advisor
Analyze SQL queries for sargability anti-patterns, missing composite indexes, wildcard pitfalls, and inefficient offsets. Generates optimized queries and DDL indexes for PostgreSQL, MySQL, and SQLite.
BigQuery & Cloud Run Cost Calculator
Model BigQuery streaming vs Storage Write API vs GCS batch ingestion costs. Calculate active storage, partitioning savings, and export Terraform, Python, and SQL setups.
URL Parser & Encoder/Decoder
Parse any URL to inspect its scheme, host, path, and query parameters. Safely encode or decode URI components instantly.
Developer Copy & Paste Tool
Paste large technical posts, code snippets, or prompts. Inspect line & word counts, strip YAML frontmatter, generate shareable links, and copy in 1 click.
Next.js Hydration Error Matcher & Fixer
Paste Next.js or React hydration error logs (Error 418, 423, 425) to instantly diagnose the root cause and generate clean, copy-paste code fixes.
Crypto Hash, HMAC & UUID Generator
Generate SHA-256, SHA-512, and HMAC-SHA256 signatures, encode/decode Base64, verify checksums, and generate bulk UUID v4 strings.
Cron Schedule Builder & Translator
Build, translate, and calculate cron schedules in plain English. Preview the next 5 execution dates and copy ready-to-run Crontab or GitHub Actions YAML.
Chmod & Linux Permissions Calculator
Convert between octal (755, 644, 600) and symbolic (rwxr-xr-x) Linux permissions with an interactive matrix and shell command builder.
AI CLI & Terminal Output Cleaner
Sanitize copied terminal logs, AI agent CLI outputs, and shell commands. Strip ANSI color codes, $ prompts, code fences, line numbers, and spinners.
JWT Debugger & Inspector
Decode, inspect, and analyze JSON Web Tokens in real-time. Check claims, expiration countdowns, and verify payloads with 100% private offline parsing.
SVG to JSX / TSX
Convert raw SVG code or files into clean, reusable React components with TypeScript types.
CSS Glassmorphism Studio
Design modern frosted glass UI with live backdrop-filter sliders and instant Tailwind CSS / CSS export.
JSON to TypeScript & Zod
Generate strictly typed TypeScript interfaces and Zod schemas directly from any JSON payload.
Open Graph & Social Meta
Preview your website on Google, Twitter/X, and LinkedIn. Generates HTML meta tags and Next.js Metadata.
About the developer tools suite
The Developer Mini-Tools Suite is a curated set of fast, privacy-respecting, in-browser utilities for web engineers. Each tool solves a single, common problem that would otherwise cost you 15 minutes of context switching: copy-pasting SVG into a component, hand-typing a Zod schema from a JSON sample, tweaking backdrop-filter values until they look right, or wondering whether your Open Graph image will crop awkwardly on LinkedIn. Everything runs locally in your browser. Nothing is uploaded, nothing is logged, nothing is rate-limited beyond what your own network can handle. The tools work offline once the page is loaded. They are designed to slot directly into modern React/Next.js workflows: the SVG converter outputs typed TSX, the JSON tool produces Zod schemas ready for use with react-hook-form, and the meta-tag generator emits Next.js Metadata objects you can drop into your app/layout.tsx.
Tool categories
Tools are organised into three categories so you can find what you need quickly:
- React & TypeScript: converters and generators that output typed, idiomatic React/TSX code or Zod schemas you can drop into a Next.js or Vite project.
- CSS & Styling: visual playgrounds for modern CSS techniques such as glassmorphism, with live preview and one-click CSS or Tailwind class output.
- SEO & Meta: generators and previewers for Open Graph, Twitter Card, and general meta tags, including a Next.js
Metadataexport.