Data and Format Work
Clean and transform payloads with JSON Formatter, CSV↔JSON, and YAML↔JSON.
Developer & agent tools
247 browser-native tools and REST APIs for developers and the agents they build. No signup, no keys — run the computation in a tab or call the endpoint.
LLM Token Counter
Count tokens across 30+ AI models with live pricing.
Count tokens and estimate model costs across GPT, Claude, Gemini, Llama, and more — with optional free API access for apps and agents
Agent Skill Validator
Cross-framework skill linting for AI agents.
Validate skill definitions across OpenClaw, Claude, Codex, and MCP with portability scoring and exact fixes
LLM Output Diff Tool
Diff two model responses line-by-line or word-by-word.
Compare outputs from different AI models side-by-side with diff highlighting
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API Suite — fast REST endpoints for app and agent workflows
API + Agent Integrations — REST APIs, OpenAPI, skills bundles, and WebMCP
Compare AI API costs across providers for your specific workload
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AI Dev Hub is a browser-based toolkit with 250+ utilities plus free REST APIs for developers, AI builders, and technical teams. Common workflows include data formatting, API prototyping, prompt engineering, model cost estimation, schema validation, and agent tool orchestration.
Clean and transform payloads with JSON Formatter, CSV↔JSON, and YAML↔JSON.
Prototype endpoints and contracts using CSV Endpoint Builder, OpenAPI Preview, and API Header Builder.
Build safer AI systems with Token Counter, Guardrail Rule Tester, and Agent Skill Validator.
Browse by category: Dev Tools, AI Tools, Formatters, Converters, Generators. For LLMs and agents, machine-readable indexes are available at /api/tools.json, /api/tools-index.json, /llms-full.txt, and /.well-known/webmcp.json. For API and agent integrations, see /agents/.