Developer Tools
JSON Formatter
Format, validate, and beautify JSON data
Schema Explorer
ER diagram & data dictionary from database DDL — Postgres, MySQL, Oracle & more
Remove Duplicate Lines
Remove duplicate lines from text
Compare Lists
Intersection, union, and difference of text lines
URL Encoder/Decoder
Encode and decode URL strings
Base64 Encoder/Decoder
Encode and decode Base64 strings
GZip & Base64
Compress with GZip and encode to Base64
Text Extractor
Extract text patterns from data
DBeaver Password Decrypt
Decrypt DBeaver saved passwords
DateTime Converter
Convert between Unix epoch, ISO 8601, and human readable
IP Address, ISP & Cloud Lookup
Look up ISP, ASN, approximate location, reverse DNS, and provider ranges
Access Log Analyzer
Inspect Nginx, Apache, and JSON traffic logs; share a report
CIDR Calculator
Calculate IP ranges, subnet masks, and host counts
XML Formatter
Pretty print and validate XML documents
XML ↔ JSON Converter
Bidirectional conversion between XML and JSON
Image ↔ Base64
Convert images to Base64 and vice versa
UUID Generator
Generate UUID v4 (random) and v7 (timestamp-based)
JWT Decoder
Decode and inspect JSON Web Tokens
Hash Generator
Generate MD5, SHA-1, SHA-256, SHA-512 hashes
Regex Tester
Test regular expressions with live highlighting
Color Converter
Convert between HEX, RGB, and HSL color formats
Text Diff
Compare two text files line by line
ASCII Table Converter
Convert terminal tables into editable HTML, CSV, Excel, or PDF
ASCII Table Generator
Generate terminal tables from CSV, TSV, JSON, or HTML
Certificate Inspector
Inspect and convert X.509 PEM, DER, CER, and PKCS#7 certificates
Java Thread Dump Analyzer
Find JVM deadlocks, blocked threads, lock contention, and repeated stacks
JSON Diff
Compare JSON objects with semantic diff
Cron Parser
Parse cron expressions to human readable format
YAML ↔ JSON Converter
Bidirectional conversion between YAML and JSON
CSV ↔ JSON Converter
Convert between CSV and JSON formats
Case Converter
Convert between camelCase, snake_case, kebab-case, etc.
QR Code Generator
Generate and read QR codes
Password Generator
Generate strong, random passwords
Unix Permissions
Calculate chmod permissions (755 ↔ rwxr-xr-x)
Protobuf Converter
Convert between JSON and Protocol Buffers
Avro Converter
Convert between JSON and Apache Avro
TOON Converter
Convert JSON/YAML to TOON for 30-60% LLM token savings
API Client
Test REST APIs with custom headers and body
Kafka Message Browser
Browse Kafka messages by partition, offset or time, and replay a selected range
Kafka Consumer Diagnostics
Inspect consumer group lag, assignments and offset reset previews
WebSocket Client
Test WebSocket connections in real-time
SSE Client
Connect to Server-Sent Events streams
Free Online Developer Tools
A collection of free online tools for developers. Format JSON, encode and decode data, analyze diagnostics, investigate network traffic, and more. Most processing stays in your browser; tools that make network requests explain exactly what they send.