34 tools DEV

Free Developer Tools

An everyday toolbox for modern engineers: decode JWTs, test and explain regexes, count AI prompt tokens, inspect stack traces and source maps, and generate strongly-typed code from JSON for TypeScript, Go, Dart, Rust, C#, Pydantic, Zod, and more. Every tool runs client-side — your code never touches a server.

Runs in browserNo signup requiredAI-enhanced

34 tools in this category

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LocalAI

JWT Decoder

Decode, inspect, and validate JWT tokens with claim analysis.

jwtdecodeDEV
LocalAI

Cron Parser

Parse, validate, and build cron expressions with human-readable explanations.

croncrontabDEV
LocalAI

Regex Tester

Test, debug, and explain regular expressions with real-time match highlighting.

regexregexpDEV
Local

Regex Explainer

Break down any regex into plain English, token by token.

regexregexpDEV
LocalAI

JSON to TypeScript & Schema Generator

Generate TypeScript interfaces, Zod schemas, and Valibot schemas from JSON.

jsontypescriptDEV
Local

AI Token Counter

Count tokens and estimate API costs for major LLMs instantly.

tokensaiDEV
LocalAI

AI Prompt Builder

Build structured LLM prompts with per-section token counting, variable injection, and provider-aware exports for OpenAI, Anthropic, and Google.

aipromptDEV
Local

Number Base Converter

Convert numbers between binary, octal, decimal, hexadecimal and custom bases.

binaryoctalDEV
LocalAI

JSON Path Tester

Query and extract data from JSON documents using JSONPath.

jsonjsonpathDEV
Local

Env File Parser & Converter

Parse, validate, and convert .env files between formats.

envdotenvDEV
LocalAI

Stack Trace Analyzer

Parse and analyze stack traces with AI-powered error explanations.

stack-traceerrorDEV
LocalAI

Tech Stack Detector

Detect frameworks, libraries, and technologies used by any website.

tech-stackdetectorDEV
LocalAI

Source Map Explorer

Resolve minified stack traces back to original source code using source maps.

source-mapminifiedDEV
AI

GraphQL Query Builder

Build and test GraphQL queries with schema introspection and AI suggestions.

graphqlapiDEV
LocalAI

Prompt Injection & Secret Scanner

Scan prompts, code, and text for prompt injection patterns, secret leaks, unsafe instructions, and PII exposure.

aipromptDEV
LocalAI

MCP Schema Validator

Validate, format, and debug MCP (Model Context Protocol) server schemas.

mcpmodel context protocolDEV
Local

JSON to Dart

Convert JSON to Dart classes with null-safety and json_serializable support.

jsondartDEV
Local

JSON to Go Struct

Convert JSON to Go structs with json tags and idiomatic naming.

jsongoDEV
Local

JSON to TypeScript

Convert JSON to TypeScript interfaces or type aliases instantly.

jsontypescriptDEV
Local

JSON to Zod Schema

Convert JSON to Zod schema definitions for runtime validation.

jsonzodDEV
Local

JSON to Rust Struct

Convert JSON to Rust structs with serde Serialize/Deserialize derive macros.

jsonrustDEV
Local

JSON to C# Class

Convert JSON to C# classes with System.Text.Json or Newtonsoft serialization.

jsoncsharpDEV
Local

JSON to Pydantic Model

Convert JSON to Pydantic v2 BaseModel classes for Python and FastAPI.

jsonpythonDEV
Local

JSON to SQL Converter

Convert JSON arrays to SQL CREATE TABLE and INSERT statements.

jsonsqlDEV
Local

JSON to Protobuf Schema Generator

Generate Protocol Buffer (.proto) schema definitions from JSON objects.

jsonprotobufDEV

OpenAPI to Postman Collection Converter

Convert OpenAPI/Swagger specs to Postman Collection v2.1 JSON.

openapiswaggerDEV

Postman to OpenAPI Converter

Convert Postman Collection v2.1 JSON to OpenAPI 3.0.0 specification.

postmanopenapiDEV
Local

GraphQL Schema to TypeScript Generator

Generate TypeScript types from GraphQL SDL schema definitions.

graphqltypescriptDEV
Local

JSON to .env Converter

Convert JSON configuration objects to .env files, Docker env, or Kubernetes ConfigMaps.

jsonenvDEV
Local

Docker Compose to Kubernetes

Convert docker-compose.yml to Kubernetes Deployment, Service, ConfigMap, and PVC manifests.

dockerkubernetesDEV
Local

Protobuf Inspector

Parse and inspect Protocol Buffer .proto files — view message structures, field types, enums, and services.

protobufprotoDEV
Local

JSON to Parquet Converter

Convert JSON arrays to Apache Parquet columnar format using DuckDB WASM, right in your browser.

jsonparquetDEV
LocalAI

Kubernetes YAML Validator

Validate, lint, and format Kubernetes manifests against structure rules, deprecated APIs, and security best practices.

kubernetesk8sDEV
Local

LLM JSON Schema Generator

Generate JSON Schema for LLM structured outputs — OpenAI, Anthropic, Gemini, Ollama.

json-schemallmDEV

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Frequently Asked Questions

Are the developer tools free?+

Yes, all 34 developer tools are free with no usage limits. JWT decoding, regex testing, JSON-to-code generation, and everything else runs directly in your browser.

Can these tools generate code from JSON?+

Yes. The codegen tools accept a JSON document and output typed definitions for TypeScript interfaces, Go structs, Dart classes, Rust structs, C# classes, Pydantic models, Zod schemas, SQL schemas, and more.

Does the JWT decoder send my token anywhere?+

No. The JWT decoder parses the token locally in your browser and shows the raw decoded header and payload. Nothing is transmitted, stored, or logged.

Do I need an account to use these developer tools?+

No account or signup is required. Tools work instantly on paste for quick regex testing, JWT inspection, and code generation.