DevFormats

Fast Developer Tools for Structured Data

Format, validate, convert and generate JSON, YAML, XML, JWT, CSV and more — all processed locally in your browser.

Turn off your wifi — the tools still work. Nothing is ever uploaded.

Popular Tools

JSON Formatter

Beautify and pretty-print JSON with configurable indentation.

JSON Validator

Check JSON syntax against RFC 8259 with exact line/column error reporting.

JSON Parser

Parse JSON and get clear, actionable syntax error explanations.

JSON Viewer

Browse JSON as a collapsible tree with search and path copy.

YAML Formatter

Format and validate YAML with 2-space or 4-space indentation.

XML Formatter

Pretty-print XML with namespace, CDATA, and comment support.

JWT Decoder

Decode JWT header, payload, and signature with expiry and algorithm warnings.

Base64 Encode/Decode

Encode or decode Base64 for text and files, Unicode-safe.

CSV to JSON

Convert CSV to JSON with delimiter detection and header toggle.

JSON to YAML

Convert JSON to YAML while preserving key order.

Browse by Category

8 tools
JSON

Format, validate, minify, view, query, and diff JSON documents.

3 tools
YAML

Format, validate, and parse YAML configuration files.

3 tools
XML

Format, validate, and parse XML documents with namespace support.

6 tools
Converters

Convert between JSON, YAML, XML, CSV, and TypeScript.

3 tools
Generators

Generate TypeScript interfaces, Go structs, and Python dataclasses from JSON.

5 tools
Encoding

Base64, URL, and HTML encode/decode utilities.

1 tool
JWT

Decode and inspect JSON Web Tokens.

Recently Added

HTML Encode

Escape HTML entities to safely display raw markup as text.

HTML Decode

Unescape HTML entities back to raw characters.

URL Encode

Percent-encode text for safe use in URLs.

URL Decode

Decode percent-encoded URL text back to plain text.

Go Struct Generator

Generate Go structs with JSON tags from a JSON document.

Python Dataclass Generator

Generate Python dataclasses from a JSON document.

YAML Validator

Validate YAML syntax against the YAML 1.2 spec.

YAML Parser

Parse YAML and inspect the resulting document structure.

Why DevFormats

⚡
Fast

Runs instantly, no upload, no queue.

🔒
Privacy First

Everything stays in your browser. Nothing is uploaded, ever.

🌍
Free

Unlimited usage. No signup, no limits, no watermarks.

💻
Built for Developers

Keyboard shortcuts, dark mode, responsive on any device.