JSON Formatter & Validator
Format, minify, and validate JSON with useful error locations.
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Developer tools
Format, validate, inspect, and transform code, configuration, schemas, test data, and developer-focused text in private browser workspaces.
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12 categoriesDeveloper
14 tools available
UUID v4 Generator
Generate one or many cryptographically strong UUID v4 identifiers.
DeveloperRegex Tester, Debugger & Visualizer
Test, explain, visualize, secure, and benchmark regular expressions locally.
DeveloperJavaScript & HTML Playground
Write HTML, CSS, and JavaScript with a sandboxed preview and captured console.
DeveloperJSON Schema Validator & Mock Data Generator
Validate, infer, build, compare, mock, and convert JSON Schema and OpenAPI models.
DeveloperConfig Format Converter & Validator
Convert, format, query, inspect, and compare YAML, JSON, TOML, XML, and INI locally.
DeveloperGit Repository & Patch Reviewer
Review diffs, patch revisions, risks and local repository history without sending code to a server.
Developeri18n Resource & Localization QA Checker
Compare resources, find placeholder and key defects, pseudo-localize and convert formats locally.
DeveloperTest Data & Fixture Generator
Generate deterministic, locale-aware and relational fixtures from visual fields or JSON Schema.
DeveloperJSON Query & Transformation Tool
Query JSON, YAML and JSONL locally, inspect canonical paths and export structured results.
DeveloperPairwise Test Matrix Generator
Generate deterministic 1-way, pairwise or 3-way test suites with exclusion constraints.
DeveloperJavaScript Bundle & Source Map Analyzer
Inspect bundle composition, Source Maps, budgets and build deltas without executing imported code.
DeveloperDesign Token & CSS Theme Editor
Edit, resolve, preview and export DTCG design tokens and CSS themes locally.
DeveloperLLM Token Counter & Context Calculator
Count tokens, compare encodings, budget messages and split prompts with local tiktoken.
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