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JSONCraft

Free JSON & Data Tools

Every JSON task, instantly

Format, validate, convert, diff, visualize — 23 browser tools for JSON, YAML, CSV, TOML and XML. No signup, no upload, nothing leaves your tab.

Open JSON Formatter

JSONCraft started as a single JSON formatter and grew into a focused suite covering the recurring tasks that show up alongside JSON in real codebases — schema validation, structural diffing, YAML and TOML and CSV conversion, JSONPath queries, and the small developer utilities (regex tester, base64 encoder, UUID generator, cron parser, timestamp converter, hash calculator) that you would otherwise hop between five different tabs to use. Every tool is keyboard-driven, deep-linkable, and shares a consistent input/output panel so the muscle memory transfers.

Privacy is the design constraint, not a marketing tag. The entire suite is static HTML and TypeScript shipped from Cloudflare's edge — there is no backend, no upload step, no signup wall, no telemetry on the data you paste in. Whatever you put into a JSONCraft tool stays in your browser tab; closing the tab discards it. That makes JSONCraft a viable choice for handling production payloads, customer data fixtures, signed JWT debug dumps, internal config files, and anything else you would not paste into a third-party site whose data-handling story you cannot audit.

Core

JSON Formatter Validate, beautify or minify JSON in real time JSON Diff Compare two JSON documents side by side JSON Tree Viewer Explore JSON as a collapsible tree JSON Graph Visualizer Visualize JSON as an interactive graph JSONPath Tester Test JSONPath expressions with live evaluation

Converters

YAML to JSON Convert YAML files to JSON instantly JSON to YAML Convert JSON to clean readable YAML JSON to CSV Convert JSON arrays to spreadsheet CSV CSV to JSON Convert CSV data to structured JSON JSON to TOML Convert JSON to TOML configuration TOML to JSON Convert TOML config files to JSON JSON to TypeScript Generate TypeScript interfaces from JSON JSON to HTML Table Convert JSON arrays to HTML tables XML Formatter Format, prettify or minify XML documents

Dev Tools

Regex Tester Test regex with live matches and groups Base64 Encode/Decode Encode text to Base64 or decode back URL Encoder/Decoder Percent-encode or decode URLs safely Hash Generator Generate MD5, SHA-1, SHA-256, SHA-512 UUID Generator Generate random UUID v4 strings in bulk Timestamp Converter Convert Unix timestamps to dates and back Cron Expression Builder Build cron expressions with next-run preview YAML Validator Validate YAML with line-precise errors JSON Schema Validator Validate JSON against a JSON Schema

23 free developer tools

No signup, no limits. Everything runs locally in your browser.

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