AI Developer Tools
Free AI developer tools: generate JSON Schema and OpenAI, Claude, and Gemini tool definitions in your browser, fill prompt templates, count tokens and estimate API cost, and get explanations for code, SQL, and error messages. The explanation tools send your input to an AI API — see each tool and our Privacy Policy.
6 tools in AI
AI Code Explainer
Paste any code snippet and get a plain-English explanation instantly, powered by AI. Free tool for understanding unfamiliar code in any language.
AI Error Message Explainer
Paste any error message or stack trace and get a plain-English diagnosis with a suggested fix, powered by AI. Free, no sign-up.
AI Text-to-SQL Generator
Describe the query you need in plain English and get a ready-to-use SQL statement, powered by AI. Free tool with dialect support.
JSON Schema Generator
Generate JSON Schema, TypeScript, Zod, and Python types from sample JSON, plus OpenAI, Anthropic, and Gemini tool definitions. Free and private in your browser.
Prompt Template Filler
Fill in {{variables}} in any AI prompt template instantly online, for free. Open the resolved prompt directly in ChatGPT with one click.
Token Counter & Estimator
Count tokens, compare current GPT, Claude, Gemini, and DeepSeek models, and forecast API costs with output, caching, batch, and volume controls.