Small fixes, fast.
Developer tools
Format JSON, encode Base64 and URLs, generate UUIDs and convert timestamps.
11 live
- Live
JSON Formatter
Format, validate and minify JSON — with exact error positions.
Developer - Live
Base64 Encode / Decode
Encode text or files to Base64, and decode it back.
Developer - Live
URL Encode / Decode
Percent-encode text for URLs, or decode it back.
Developer - Live
UUID Generator
Generate random v4 UUIDs — one or a hundred at a time.
Developer - Live
Timestamp Converter
Convert Unix timestamps to dates and back, in local time and UTC.
Developer - Live
Hash Generator
MD5, SHA-1, SHA-256 and SHA-512 for text or any file.
Developer - Live
JWT Decoder
Decode a JWT's header and payload and check its expiry.
Developer - Live
Regex Tester
Test regular expressions with live match highlighting and groups.
Developer - Live
CSV to JSON Converter
Convert CSV to JSON and JSON back to CSV, with a table preview.
Developer - Live
YAML to JSON Converter
Convert YAML to JSON and JSON to YAML, with exact error lines.
Developer - Live
Number Base Converter
Convert between binary, octal, decimal and hex — any size.
Developer
FAQ
About Developer tools
Quick checks without pasting your data into someone else's server: format and validate JSON, convert CSV and YAML to JSON, encode and decode Base64 and URLs, decode JWTs, generate UUIDs and hashes, test regular expressions, and convert Unix timestamps and number bases. Everything is computed in your browser, so API responses, keys and tokens stay on your machine.
The work happens in this tab and nothing is sent to a server, so the data doesn't leave your machine. Still treat live tokens as secrets and don't share screenshots of them.
Yes. They are version 4 UUIDs from your browser's cryptographic random generator, the same source used for encryption keys.
No. They are fine for checking that a download arrived intact, but they are broken for security. For anything security-related use SHA-256 or stronger, and store passwords with a dedicated password hash such as bcrypt or Argon2.