Free Online Developer Tools
28 toolsFormat code and data, test patterns, compare changes, and prepare configuration.
- JSON FormatterFormat, validate and minify JSON; upload a file and choose 2, 4 or 8-space indentation.
- JWT DecoderDecode and inspect JSON Web Tokens with claim explanations
- Base ConverterConvert numbers between binary, octal, decimal, hex
- Chmod CalculatorCalculate Linux file permissions in octal and symbolic
- HTML MinifierMinify HTML code by removing comments and whitespace
- htaccess GeneratorGenerate Apache .htaccess files for redirects and security
- JSON Tree ViewerExplore and edit JSON in a collapsible tree
- CSS MinifierMinify and compress CSS code
- JavaScript MinifierMinify and compress JavaScript code
- Regex TesterTest and validate regular expressions
- Code BeautifierFormat and beautify HTML, CSS, JavaScript code
- API Response FormatterFormat and beautify API responses
- SQL Query BuilderBuild SQL queries visually
- Cron Job GeneratorGenerate cron expressions for scheduled tasks
- Git Commands HelperInteractive Git command generator and reference guide
- Code Diff CheckerCompare code differences with syntax highlighting
- JavaScript KeyCode FinderPress any key to get its keyCode, key, code, and which values
- CSS Unit ConverterConvert between px, rem, em, vw, vh, and other CSS units
- CSS Specificity CalculatorCalculate and compare CSS selector specificity scores
- Subnet CalculatorCalculate IPv4 subnets, network ranges, and CIDR notation
- Markdown EditorWrite and preview Markdown with live rendering and toolbar
- License GeneratorGenerate open source license files for your projects
- .gitignore GeneratorGenerate .gitignore files for any language, framework, or IDE
- Nginx Config GeneratorGenerate Nginx server configuration files visually
- Docker Compose GeneratorBuild docker-compose.yml files with a visual editor
- JSON to TypeScriptConvert JSON objects to TypeScript interfaces and types
- JSON Schema GeneratorGenerate JSON Schema from JSON data automatically
- Text EncryptionEncrypt and decrypt text using AES-256 encryption
Inspect code, data, and configuration
Format structured data, inspect tokens, test patterns, and create configuration snippets without switching between several small utilities. These tools support inspection and preparation; generated code still needs to be reviewed in the context of your application. Avoid pasting live credentials or secrets into debugging tools.
Make data easier to inspect
JSON Formatter validates and formats JSON or produces compact output. Regex Tester helps explore matching rules. Code Diff Checker highlights changes between two versions before you update a file.
Common questions
Does decoding a JWT verify that it is trustworthy?
No. Decoding shows the contents. Trust requires signature verification and checks of claims such as issuer, audience, and expiry in the application.
What is the difference between formatting and minifying JSON?
JSON Formatter adds indentation for inspection; minifying removes unnecessary whitespace for a compact representation. Neither operation should change the underlying JSON values.
Why does my regular expression behave differently in an application?
Regex engines, flags, and string escaping differ between environments. Use Regex Tester to examine a pattern, then verify it in the language and runtime where it will run.
How do I check a code change before replacing a file?
Code Diff Checker highlights changes between two inputs. Inspect the differences and run the relevant application checks before applying the new version.