Format, decode and convert. Nothing leaves your browser.
Small, fast developer tools for everyday API work. Tokens and responses you paste stay on your machine.
All tools
- Format and validate JSON formatter and validator Format, minify and validate JSON, with the exact line and column of any syntax error.
- Encode and decode JWT decoder Read a JWT's header and payload, with issued-at and expiry times shown as real dates.
- Encode and decode Base64 encoder and decoder Encode and decode Base64 and Base64URL, with full Unicode support.
- Convert JSON to TypeScript, Zod and Java Paste a JSON response and get TypeScript interfaces, a Zod schema or Java classes with Jackson annotations.
- Convert YAML to JSON converter Convert YAML to JSON and JSON to YAML, with the exact line of any syntax error. Handles multi-document files.
- Text and regex Regex tester Test JavaScript regular expressions with live match highlighting, capture groups and replace preview.
- Encode and decode URL encoder and decoder Percent-encode and decode URLs and query values, and break a URL into its parts and parameters.
- Convert Unix timestamp converter Convert Unix timestamps in seconds or milliseconds to dates, and dates back to timestamps.
- Convert Cron expression explainer See what a cron expression means in plain English, what each field does and the next times it will run.
- Convert JSON to CSV converter Turn a JSON array into CSV for Excel or Google Sheets, or a CSV file into JSON. Nested objects become columns.
- Generate and hash UUID generator and inspector Generate UUID v4 and time-ordered v7 in bulk, or paste a UUID to see its version and timestamp.
- Text and regex Text diff checker Compare two texts line by line and see exactly what was added, removed or changed.
- Generate and hash Hash and HMAC generator SHA-256, SHA-1, SHA-384 and SHA-512 hashes and HMAC signatures of text, in hex or Base64.
- Text and regex Markdown previewer Write Markdown on the left and see it rendered live on the right, with GitHub-style tables and task lists.