110+ cloud cost calculators, developer utilities, and AI/LLM tools — JWT decoding, key generation, PII redaction, sizing math — computed entirely client-side. No backend. No uploads. No server ever sees your data.
36 cloud architecture and cost calculators — database sizing, streaming capacity, compute tuning, and network cost planning, plus an interactive design canvas.
Browse all 36 tools ➔54 free, in-browser developer tools — formatters, converters, generators, and encoders. No signup, no server round-trip, no rate limits.
Browse all 54 tools ➔21 free tools for working with LLMs — token and cost estimation, prompt engineering, structured output schemas, and RAG/embedding planning. All client-side, no API key required.
Browse all 21 tools ➔Common questions about how DevTools Suite works.
Yes — every calculator and utility on this site is free, with no signup, no paywall, and no usage limits. There's no premium tier hidden behind these tools.
No. Every tool runs as JavaScript in your browser — there's no backend for your input to be sent to. Whatever you paste into the JSON formatter, JWT decoder, PII redactor, or any other tool stays on your device. See the Privacy Policy for the full breakdown.
Once a tool's page has finished loading, yes — everything runs locally with no further network requests. You do need a connection to load a page the first time, since each tool lives at its own URL.
They're built from published cloud provider pricing and known capacity formulas at the time they were written, meant for planning and estimation — not a substitute for a real quote. Provider pricing changes and varies by region and commitment tier, so always confirm exact numbers with the provider before budgeting against them.
Not currently — Modern Developer Toolkit is a browser-based tool suite. If that's something you'd find useful, mention it via the Contact page.
No third-party analytics, ad trackers, or tracking cookies. The only thing stored is your light/dark theme preference, saved locally in your browser.
Yes — that's exactly what the Contact page is for. Bug reports and tool requests are both welcome.