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oneirozzzz7
oneirozzzz7

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17 free browser-based tools for LLM API developers

I kept switching between 5+ different sites just to count tokens, estimate API costs, plan context windows, and format JSON. So I built DevKit AI — a free collection of 17 tools specifically for LLM API workflows.

Link: https://devkit-ai.com

Key tools

  • Token Counter — supports 60+ models (GPT-4, Claude, Gemini, Llama)
  • LLM Pricing Calculator — 64 model families, daily-synced pricing, benchmark scores
  • Context Window Planner — visualize token budget allocation
  • JSON Suite — formatter, diff, JSON-to-TypeScript, JSONPath, schema validator

Technical decisions

  • All computation is client-side (Web Workers + WASM) — zero data transmission
  • Next.js 15 on Vercel
  • Pricing data synced daily from official sources
  • No auth, no accounts, no tracking

Everything runs in your browser. Free, no signup, available in 8 languages.

Curious to hear what tools you wish existed for your LLM workflow!

Top comments (1)

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bhavin-allinonetools profile image
Bhavin Sheth

Love the client-side approach. I use token counters and pricing calculators almost daily, so having everything in one place without signup is a huge time saver.