Free tools

Small tools for serious engineering work.

Useful calculators and utilities built from the engineering decisions behind RAG, agents, frontend systems, and production web apps. No sign-up and no data leaves your browser.

Available now

05 tools

Vector & AST

SVG to JSON & JSX

Parse SVG to clean structured JSON AST, extract path coordinates, or generate typed React JSX components.

AST JSONPath extractionReact JSX & previewOpen

Model economics

LLM API Cost Calculator

Compare OpenAI, Claude, and Gemini spend from request volume, input, output, and cached tokens.

9 current modelsCache pricingCost comparisonOpen

Student survival

Can I Bunk Today?

Calculate attendance, classes needed to recover, and exactly how many you can safely miss.

75% calculatorSafe bunksFunny verdictsOpen

Tokenization

Prompt Token Counter

Count tokens locally with real o200k, cl100k, and p50k tokenizers.

Exact encodingContext usageLocal processingOpen

RAG engineering

RAG Chunking Calculator

Estimate chunks, overlap duplication, retrieval context, and raw vector storage.

Token estimateVector storageRetrieval budgetOpen

Purpose-built

Each tool answers a real engineering question—not a generic AI wrapper.

Local by default

Calculator inputs stay in your browser. No documents or project data are uploaded.

Production-minded

Results include the trade-offs and caveats that quick demos usually ignore.