Free Online Developer Tools

Format and validate JSON, with syntax error detection

Advanced JSON validation with JSON Schema support

Format YAML files and detect syntax errors

Format and validate XML documents

Format SQL queries for readability

Convert between JSON and YAML formats

Convert between JSON and XML formats

Convert between JSON and CSV formats

Convert between timestamps and date/time formats

Convert between HEX, RGB, HSL and other color formats

Base64 encode and decode for text and files

Convert between px, rem, em, vw and more

Calculate accurate age from a birth date

Compare two pieces of text and highlight differences

Convert images to ICO favicons in multiple sizes

Resize images in batch with multiple format support

Convert between images and Base64 strings

Customize colors, shapes, background and center logo

Generate mock data for testing

Generate random UUIDs / GUIDs

Generate strong random passwords with custom rules

Create A4 tianzige tracing sheets with pinyin, auto pagination, print ready

Generate mental-math and vertical arithmetic drills with A4 print

URL encoding and decoding

Encode and decode HTML special characters

Convert between text and Unicode escapes

Decode and inspect JWT tokens

Test and debug regular expressions

Generate and parse cron schedule expressions