About Rocket Dev Tools
A single home for the small, repetitive tools developers reach for constantly — cloud sizing math, format conversions, encoding, key generation — built around one rule: nothing you type or paste is ever sent anywhere.
Why this exists
Most "free online tools" — JSON formatters, JWT decoders, hash generators — work by uploading whatever you paste to a server, running it there, and sending back a result. That's a strange amount of trust to ask for, especially when what people paste into these tools is often exactly the kind of thing that shouldn't leave their machine: API keys, auth tokens, internal config, customer data samples. Rocket Dev Tools exists because that tradeoff shouldn't be necessary. Every calculator and utility here runs as JavaScript in your browser — the computation happens locally, and there's no backend for your input to travel to in the first place.
What's here
Three suites, one architecture: an Architecture Suite for cloud sizing and cost calculators (databases, streaming, compute, networking), a Developer Utilities suite for the everyday formatters, encoders, and generators, and an AI & LLM Tools suite for token counting, prompt engineering, and structured-output schemas. All three follow the same rule — client-side only.
How it's built
This is an independently built and maintained project, not a company product. It's a static site — no user accounts, no database, no server-side processing of anything you enter. The only state kept anywhere is your theme preference (light/dark), stored in your browser's local storage. That architecture isn't a marketing angle; it's the actual reason the privacy claim on the homepage is true rather than aspirational.
Accuracy and limits
Cost and sizing calculators are built from published provider pricing and known capacity formulas at the time they were written — they're planning tools, not invoices. Cloud pricing changes; always confirm real numbers with the provider before budgeting against them. Token-count estimates in the AI tools are approximations of real tokenizer behavior, not exact counts. Where a tool has a specific limitation, it's noted on that tool's page.
Questions or feedback
Found a bug, want a tool added, or have a question about how something works? See the Contact page — or check the FAQ first, it covers the most common questions.