Formatting and validation tools

Structured data needs to be readable by humans and machines. These tools make JSON and XML easier to inspect, edit, and validate without installing anything.

JSON

JSON Formatter

Format, validate, minify, and sort JSON. Free, offline, runs in your browser.

JSON Validator

Validate JSON and get the exact error location for invalid input.

JSON Minifier

Remove all non-essential whitespace from JSON.

JSON Compare

Semantic JSON diff that ignores key order and whitespace.

JSON Schema Validator

Validate a JSON document against a JSON Schema. Lists every error with its path. Draft-07. Runs entirely in your browser.

XML

XML Formatter

Format, validate, and minify XML. Free, offline, runs in your browser.

XML Validator

Validate XML and get the exact error location.

XML Minifier

Remove all non-essential whitespace from XML.

XML to JSON

Convert XML to JSON and JSON to XML. Attributes become @keys, text becomes #text, repeated elements become arrays. Runs in your browser.

Sitemap Validator

Validate a sitemap XML file against the sitemaps.org protocol.

YAML

YAML to JSON

Convert YAML to JSON and back, entirely in your browser.

YAML Formatter

Format and validate YAML. Detects syntax errors with line numbers. Preserves comments, anchors, and multi-document streams.

CSV

CSV to JSON

Convert CSV to JSON and back, entirely in your browser.

TOML

TOML to JSON

Convert TOML to JSON and back. Exact conversion, clear error reporting, no uploads or tracking.

SQL

SQL Formatter

Format and beautify SQL queries online. 19 dialects including PostgreSQL, MySQL, T-SQL, and BigQuery. Runs entirely in your browser.

MIME

MIME Type Lookup

Look up the MIME type for any file extension, or find extensions for a MIME type. Complete IANA registry. Runs in your browser.

Markup

HTML Formatter

Format, minify, and check HTML. Uses Prettier for formatting. Handles embedded CSS and JavaScript. Runs entirely in your browser.

About format tools

JSON is the lingua franca of APIs and configuration. Formatting it with indentation makes it readable. Minifying it removes whitespace before transmission. Validating it catches trailing commas, unescaped quotes, and other common syntax errors before they reach a server.

XML is stricter and more expressive than JSON, and still used in SOAP APIs, RSS feeds, sitemaps, and configuration files. Small mistakes in XML nesting produce cryptic parser errors; these tools point to the exact line and character.

All processing happens in your browser. Large documents are handled with a streaming formatter where possible, and nothing is uploaded to a server.