Every developer has a toolkit of small utilities they reach for constantly — a quick way to format JSON, test a regex, encode a string, or compare two files. Installing desktop apps for each of these is overkill. These 10 browser-based tools are fast, private (client-side only), and always available without any login.
Paste raw JSON to instantly format it with proper indentation, catch syntax errors, and collapse/expand nested objects. Invaluable when debugging API responses.
Write and test regular expressions against sample text in real-time. Highlights matches, shows capture groups, and supports multiple flavours.
Encode strings or files to Base64 and decode them back. Essential for working with data URIs, JWT tokens, and API authentication headers.
Generate one or a batch of RFC 4122-compliant UUIDs (v4) in a single click. Copy individually or all at once.
Paste two versions of a file or code block side-by-side to see exactly what changed — added, removed, or modified lines highlighted clearly.
Paste a JWT token to instantly decode the header and payload. Useful for debugging auth issues — see expiry, user ID, and claims without touching a library.
Encode special characters in URLs and decode encoded strings back to readable form. Handles both encodeURIComponent and full URL encoding.
Generate MD5, SHA-1, SHA-256, and SHA-512 hashes from any string. Useful for checksums, password debugging, and data integrity verification.
Build and validate cron expressions visually. See exactly when a schedule will fire next — no more second-guessing your */5 * * * *.
Convert JSON arrays to CSV in one click — ideal for exporting API data to spreadsheets without writing a script.