Developer tools
16 free developer tools · Format data, inspect tokens and generate IDs
Make a JSON response readable, convert an export, test a JavaScript regular expression or generate identifiers. Each tool handles a small part of a development task. A JSON syntax check does not check an application’s rules, and reading a JWT does not verify its signature.
All developer tools
- JSON formatter & validator Format or minify JSON, check its syntax and sort keys.
- JSON ↔ YAML ↔ XML Convert between JSON, YAML and XML in any direction.
- JWT decoder Read JWT claims and expiry; signatures are not verified.
- Base64 encode & decode Encode or decode Base64, including URL-safe variants.
- Password generator Generate random passwords with your chosen length and characters.
- URL encode & decode Percent-encode or decode URLs, and inspect the parts.
- HTML entity encode & decode Escape HTML special characters, or decode entities back.
- JSON ↔ CSV converter Convert between JSON arrays and CSV, both directions.
- CSV import doctor Find CSV import problems, review cell changes and download a checked copy.
- UUID generator Generate random v4 or time-ordered v7 UUIDs in bulk.
- Hash generator Calculate MD5, SHA and CRC32 values for text.
- Color converter Get HEX, RGB, HSL and HSV values, plus text contrast ratios.
- Regex tester Test a regular expression with live match highlighting.
- Cron expression generator Explain a cron expression and see its next run times.
- QR code generator Make QR codes for links, Wi-Fi, email or contacts.
- Unix timestamp converter Epoch to date and back, with the unit auto-detected.
Guides for these tasks
- JSON vs YAML vs XML: differences, trade-offs and conversion pitfalls Choose a format for the receiving system, inspect conversion changes to arrays, types and comments, and check what the local converter preserves or loses.
- Base64 is not encryption: choose encoding, encryption or hashing Decode a Base64 example, distinguish readable encoding from encryption, and understand why a hash does not make a password or other guessable data secret.
- How to read a JWT: inspect its claims without mistaking decoding for verification Read a signed JWT's header and claims, interpret expiry timestamps, and check the difference between decoded content and a token your server can trust.
- Cron syntax explained: check when a five-field schedule will run Read a five-field cron expression, check steps and day matching, and understand the local preview's UTC times and supported syntax.
- What checksums are for: verifying a download with a hash Calculate a file's SHA-256 checksum, compare the complete value with the publisher's, and understand what a match does and does not establish.
Related categories
Published by ToolsNow · Editorial standards · Report a problem