Developer Tools
JSON, encoding, regex, and dev utilities
Developer tools on Utilitoo cover the formats and transforms you reach for while debugging APIs, reviewing configs, and writing documentation. Format and validate JSON, decode JWTs, test regex patterns, diff text, convert between CSV, YAML, XML, and TOML, inspect timestamps, and more. Most utilities run entirely in your browser, so staging payloads, webhook bodies, and internal configs never leave your machine during processing. Pin a few favorites during an incident or refactor so you are not context-switching to separate desktop apps for every paste. Pair formatters with validators when a payload might be truncated or contaminated with comments from tickets or chat.
When to use this category: Open this category when you are mid-debug or mid-review and need a fast, private transform on JSON, tokens, configs, encodings, or network-related snippets.
Popular tools
- JSON Formatter
Pretty-print minified JSON from APIs, logs, and config files with readable indentation.
- JSON Validator
Find syntax errors with line-level feedback before formatting or deploying config.
- JWT Decoder
Inspect JWT header and payload claims during auth debugging - decode only, no signature verify.
Available tools
JSON & Data
JSON Formatter
Format and beautify JSON online instantly.
JSON Validator
Validate JSON syntax and find errors instantly.
JSON Viewer
Browse JSON in an interactive tree view.
JSON Schema Validator
Validate JSON data against a JSON Schema.
JSON Minifier
Minify JSON by removing whitespace.
CSV Viewer
View and inspect CSV data in a table.
JSON to CSV
Convert JSON arrays into CSV files.
JSON Compare
Compare two JSON documents side by side.
JSON to XML
Convert JSON data to XML format.
XML to JSON
Convert XML documents to JSON format.
CSV to JSON
Convert CSV data into JSON arrays.
JSON to YAML
Convert JSON documents into YAML format.
YAML to JSON
Convert YAML documents into JSON format.
TOML Formatter
Format and normalize TOML configuration files.
TOML to JSON
Convert TOML configuration into JSON format.
Encoding & Decoding
Base64 Encode / Decode
Encode and decode Base64 strings instantly.
JWT Decoder
Decode JWT tokens and inspect claims.
URL Encoder / Decoder
Encode and decode URL strings and query parameters.
HTML Escape / Unescape
Escape or unescape HTML entities.
Number Base Converter
Convert numbers between binary, octal, decimal, and hex.
Text to Binary
Convert text to binary and binary back to text.
Formatters
SQL Formatter
Format and beautify SQL queries.
YAML Formatter
Format and validate YAML configuration files.
Markdown Viewer
Preview Markdown as formatted HTML in real time.
Mermaid Editor
Edit Mermaid diagrams with live preview and export SVG or PNG.
Markdown to HTML
Convert Markdown source into HTML output.
HTML to Markdown
Convert HTML snippets into Markdown text.
XML Formatter
Format and beautify XML documents.
Text & Regex
Network
HTTP Status Codes
Searchable reference for common HTTP status codes.
MIME Type Lookup
Look up MIME types by extension or media type.
Certificate Decoder
Decode PEM X.509 certificates and inspect details.
IP Lookup
Look up IP address information.
CIDR Calculator
Calculate network details from CIDR notation.
Subnet Calculator
Calculate subnet details and split networks.
DNS Lookup
Look up DNS records for any domain.
HTTP Header Viewer
View HTTP response headers for any URL.
User Agent Parser
Parse browser user agent strings.