Free Online Developer Tools
Format JSON, convert YAML, decode Base64 and JWTs, generate UUIDs and hashes, compare text, convert timestamps and test HTTP APIs online.
Inspect data, troubleshoot requests and prepare configuration files with focused native utilities. Use sample data when debugging: these tools process submitted input on the server.
Choose a tool
JSON Formatter
Format and validate JSON online with configurable indentation and optional key sorting. Read structured output and copy or download formatted JSON.
JSON ↔ YAML Converter
Convert JSON to YAML or YAML to JSON online with readable indentation. Supports JSON-compatible data and checks unsupported values before conversion.
Base64 & URL Encoder
Encode or decode UTF-8 text as Base64 or a URL component. Convert text online with whitespace preserved and validation for malformed encoded input.
JWT Decoder
Decode a three-part JWT to inspect its JSON header and claims. For debugging test tokens; signatures, expiry, issuer and audience are not verified.
UUID Generator
Generate up to 100 cryptographically random UUID v4 identifiers online. Copy one UUID or a batch, with one identifier per line. No sign-up needed.
Hash Generator
Calculate a SHA-256 or SHA-512 hexadecimal hash from UTF-8 text online. Whitespace is included. Useful for checksums and reproducible test values.
Timestamp Converter
Convert Unix timestamps in seconds or milliseconds to UTC, or an ISO date to epoch time. Explicit timezones keep conversions predictable.
Text Compare
Compare two texts line by line and find added, removed and unchanged lines. Whitespace-sensitive online diff for configs, drafts and API output.
API Tester
Send an HTTP request and inspect its status, headers and response body. Test public endpoints using GET, POST, PUT, PATCH, DELETE or HEAD.
Regex Patterns
Build regular expressions for email, URLs, UUIDs, digits and other supported rules. Choose JavaScript, Python or PCRE, without an AI API key.
JSON Schema Generator
Generate a JSON Schema from example JSON or typed field declarations. Infer nested objects and mixed arrays, then review the schema for your application.
OpenAPI Generator
Create an OpenAPI 3.1 scaffold from HTTP methods and paths. Export YAML or JSON, then add request schemas, responses and authentication details.
Docker Generator
Generate a Dockerfile template for Node, Python or a static site, with optional Compose output. Customize the runtime, port and application build steps.
Free to use, with no required account or AI API key. Input is processed on our server. How the tools work.