44 tools DEV
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.
Master workflows, understand protocol specifications, and avoid production edge-cases.
Master .env formatting rules, resolve multiline string and certificate escaping bugs, manage .env precedence, and prevent secret leaks in CI/CD.
Transform OpenAPI (Swagger) specifications into executable Postman Collections (v2.1). Automate contract testing, generate mock servers, and streamline API integration.
Strip DOM boilerplate, convert complex HTML tables and semantic trees into clean Markdown, slash RAG embedding token costs by 60–80%, and preserve critical context for LLMs.
Transform raw cURL commands and browser network exports into production-ready JavaScript Fetch, Axios, Python Requests/HTTPX, and Go net/http code.
Learn how to convert nested JSON datasets to columnar Apache Parquet with schema inference, Snappy/ZSTD compression, and DuckDB/Athena query acceleration.
Master cryptographic hashing: evaluate collision resistance, benchmark SHA-2 vs SHA-3 vs BLAKE2, prevent length extension attacks with HMAC, and safely verify file checksums.
Resolve minified JavaScript bundle errors back to original TypeScript source code using VLQ-decoded source maps, hidden source maps, and stack trace resolvers.
A comprehensive developer debugging guide to resolving JSON Web Token (JWT) errors: signature mismatches, expired tokens, alg: none attacks, clock skew, and JWKS key rotation.
Learn how to detect frontend frameworks, CMS platforms, CDN edge layers, and server runtimes using DOM markers, script paths, and HTTP response headers.
A comprehensive developer guide to writing production-grade Dockerfiles: mastering BuildKit cache invalidation, multi-stage builds, non-root execution, and security linting.
Diagnose JavaScript bundle bloat, fix broken tree-shaking patterns, eliminate barrel file overhead, and optimize Core Web Vitals (INP/LCP) in Next.js, Vite, and Webpack.
Convert raw JSON payloads and schemas into robust, type-safe Python Pydantic V2 models. Master Field constraints, custom validation, and nested structures.
Master synthetic mock data generation for APIs: build realistic datasets using Faker, JSON Schema, and Mock Service Worker (MSW 2.0) for frontend testing and prototyping.
How to generate type-safe TypeScript interfaces, Zod runtime validation schemas, and JSON Schema definitions from arbitrary JSON payloads.
A comprehensive developer guide to identifying and fixing GitHub Actions YAML syntax errors, matrix build bugs, expression interpolation traps, and concurrency race conditions.
Generate end-to-end type safety across your GraphQL stack. Learn how to convert GraphQL SDL schemas and documents into typed queries, mutations, and resolver signatures.
Diagnose and handle HTTP 429 status codes. Master IETF standard RateLimit and Retry-After headers, and implement production-grade exponential backoff with full jitter in Node.js, Python, and Go.
Master the art of reading cryptic regular expressions by breaking patterns down into visual abstract syntax trees, grouping constructs, lookarounds, and quantifiers.
Master epoch timestamps, millisecond vs microsecond precision, RFC 3339 / ISO 8601 formatting, UTC storage rules, and prevent subtle timezone bugs across databases and APIs.
Master JSON formatting, RFC 8259 compliance, JSON Schema Draft 2020-12 validation, safe 64-bit integer handling, and high-throughput Node.js streaming.
Understand the differences between JSON and JSON Lines (JSONL / NDJSON). Learn how to stream massive datasets, format AI training data, and process lines in Python and Node.js.
Master standard JSONPath syntax, filter expressions, recursive descent, and array slicing for REST APIs, mock tests, and log filtering.
Diagnose and fix syntax errors, missing resource limits, selector mismatches, and schema validation failures in Kubernetes manifests before deployment.
Slash your OpenAI, Anthropic, and Gemini API bills by 60–80%. Master prompt caching, tiered model routing, token budgeting, and batch processing economics.
Understand BPE tokenization, calculate prompt vs output token consumption, utilize prompt caching, and budget context windows to optimize AI inference costs.
Master 5-field and 6-field cron syntax, prevent double executions during Daylight Saving Time (DST), handle UTC schedules, and debug missed server jobs.
A comprehensive developer guide to CSS selectors, specificity calculation mechanics, the :has() relational selector, forgiving selector lists, and high-performance DOM querying.
Resolve Git merge and rebase conflicts with confidence. Master standard vs diff3 conflict markers, 3-way merge logic, and conflict prevention strategies.
Learn how to convert JSON payloads into robust, idiomatic C# classes and records. Master System.Text.Json, JsonPropertyName, Newtonsoft.Json, nullable reference types, and custom converters.
Learn how to convert JSON payloads into robust, null-safe Dart models for Flutter. Master manual factory constructors, json_serializable, build_runner, and Freezed.
Learn how to convert JSON payloads into robust, idiomatic Go structs. Master struct tags, omitempty edge cases, pointer nullability, and custom unmarshaling.
Learn how to convert JSON payloads into robust, idiomatic Rust structs with Serde. Master derive macros, Option<T> nullability, rename_all, and zero-copy deserialization.
Master structured outputs with LLMs using JSON Schema Draft 2020-12, OpenAI strict schemas, Anthropic tool definitions, and token-optimized validation pipelines.
A comprehensive developer guide to positional numeral systems, arbitrary-precision BigInt radix conversions, two's complement signed arithmetic, and IEEE 754 float inspection.
A comprehensive developer guide to responsive web design, covering layout vs visual viewports, modern CSS media queries, container queries, fluid typography, and viewport testing strategies.
Diagnose slow database queries by decoding EXPLAIN (ANALYZE, BUFFERS) output trees, optimizing composite indexes, understanding bitmap heap scans, and eliminating sequential scans.
Translate Docker Compose stacks into production-ready Kubernetes manifests. Map services to Deployments, host volumes to PVCs, and env files to ConfigMaps.
A technical guide to authoring, validating, and debugging JSON Schema tool definitions for Model Context Protocol (MCP) servers in AI agents and LLM applications.
Implement bulletproof browser cookie security with SameSite=Lax/Strict, enforce host binding via __Host- and __Secure- prefixes, prevent CSRF attacks, and configure CHIPS for cross-site embeds.
A comprehensive developer guide to modern web color spaces: understanding OKLCH perceptual uniformity, Display P3 wide gamut, sRGB conversions, and accessible UI palettes.
Benchmark memory-hard Argon2id against bcrypt and PBKDF2, configure work factors for modern GPU resistance, avoid the 72-byte bcrypt truncation trap, and implement seamless on-login hash upgrades.
Generate end-to-end type safety from OpenAPI and Swagger specs. Learn how to convert OAS 3.0/3.1 JSON/YAML schemas into typed fetch clients, Zod validators, and path types.
A developer security guide to identifying direct, indirect, and multi-turn prompt injection vulnerabilities in LLM applications and agent pipelines.
A developer guide to Protocol Buffers wire format, decoding varints, resolving tag mismatches, and debugging corrupt binary gRPC and Kafka streams.
Understand NFA regular expression engine backtracking, diagnose exponential runtime traps, and fix Regular Expression Denial of Service (ReDoS) vulnerabilities.
Learn how to repair broken JSON from LLM outputs, APIs, and configs. Master automated AST recovery for trailing commas, single quotes, bare keys, and truncated streams.
Bridge the gap between compile-time TypeScript interfaces and runtime boundary validation. Learn how to generate, refine, and enforce Zod schemas from JSON payloads.
Master unidirectional SSE vs bidirectional WebSockets for modern applications. Learn HTTP/2 multiplexing, automatic reconnection, Nginx proxy buffering gotchas, and token-by-token LLM streaming.
Master IPv4/IPv6 CIDR notation, subnet mask bitwise math, usable IP ranges, broadcast addresses, and cloud VPC network design for AWS, Docker, and Kubernetes.
Master TOML v1.0.0 configuration grammar, understand arrays of tables vs inline tables, parse Cargo.toml and pyproject.toml manifests, and serialize TOML across runtimes.
Master code diff algorithms (Myers, Patience, Histogram), unified diff patch anatomy (@@ coordinates), side-by-side vs inline comparison, and patch workflows.
Master JSON Schema visualization and debugging: resolve complex $defs pointers, catch recursive circular loops, inspect validation constraints, and render OpenAPI diagrams.
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.
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.
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.
No account or signup is required. Tools work instantly on paste for quick regex testing, JWT inspection, and code generation.