Free Online JSON & Markdown Tools

Each tool runs entirely in your browser. No signup, no uploads, no servers.

JSON to TypeScript

Infer TypeScript interface definitions and array unions.

JSON to Zod

Generate Zod runtime validation schemas (z.object).

JSON to Pydantic

Convert JSON to Python Pydantic BaseModel classes.

JSON to Go Struct

Infer Golang structs with json struct tags.

JSON to Rust Serde

Generate Rust structs with #[derive(Serialize, Deserialize)].

cURL to JSON

Import cURL commands, test HTTP APIs, and inspect headers.

JWT Decoder & Redactor

Decode JWT tokens, inspect claims, and redact secrets/PII.

MongoDB Query Tester

Filter JSON arrays with $gt, $in, $regex, $elemMatch syntax.

Fix JSON Error

Pinpoint line/column numbers of syntax errors and auto-repair.

Repair Broken JSON

Auto-fix escaped quotes, unquoted keys, and Python dicts.

JSON with Comments

Strip // and /* */ comments from JSONC config files.

JSON Formatter

Beautify, minify, and sort keys with one click.

JSON Validator

Syntax + JSON Schema validation (Ajv with formats).

JSON Schema Validator

Validate payloads against JSON Schema definitions with Ajv.

JSON Visualizer

Interactive tree view, object viewer, and table grid for JSON data.

JSON Diff

Compare two documents side by side with sync-scroll.

Markdown Editor

Live preview with Mermaid, KaTeX, code highlighting.