DevFlow AI — 20 tools for developers

The problem

Working with LLMs and everyday dev utilities is fragmented: scattered micro-tools, opaque token costs, tokenisation quirks across providers. Too much friction for routine tasks.

What I built

A suite of 20 developer tools, local-first and with optional, free AI — no login, no mandatory API keys; every tool works 100% offline and AI only adds on top.

• Tools: JSON Formatter, Regex Humanizer, Token Visualizer, API Cost Calculator, DTO-Matic, Prompt Analyzer, Code Review Assistant, generators (UUID/Hash/Password), and more.
• Installable PWA, command palette (Cmd+K), MagicInput with auto-routing and shareable state via URL.
• Multi-provider AI with a free fallback chain: Gemini 2.0 Flash → Groq → OpenRouter → Pollinations (BYOK supported).
• It is the final project of the AI Development Master’s (BIG School).

Metrics (verifiable, in the docs)

• Lighthouse 100/100/100/100 (Performance/Accessibility/Best Practices/SEO) on desktop.
• 1,780 unit tests + 25 E2E specs (Playwright) · 10 CI jobs (incl. CodeQL, Semgrep, Lighthouse, a11y).
• 8 languages (EN/ES/FR/PT/DE/IT/ZH/JA), with enforced EN/ES parity.

Stack

Next.js 16 (App Router, Turbopack, React Compiler) · React 19 · TypeScript (strict, zero any) · Tailwind 4 · HeroUI v3 · GSAP + Framer Motion · Vitest + Playwright + axe-core · Clean Architecture · Vercel.