Essential Developer Code Tools: Regex, JWT, Timestamp, and HTML Formatter
Frontend developers work with many small but critical data formats daily: regular expressions for pattern matching, JSON Web Tokens for authentication, Unix timestamps for time data, and raw HTML that needs formatting. Having browser-based tools for these tasks means you can debug and transform data without leaving your workflow.
Testing Regular Expressions
Regular expressions are powerful but notoriously tricky to get right. The Regex Tester lets you write a pattern, test it against sample text, and see all matches, groups, and captured values in real time. You can also test replacement operations to verify your substitutions work as expected.
Common regex use cases include:
- Validation — email addresses, phone numbers, URLs, zip codes
- Extraction — pull specific patterns out of log files or text
- Replacement — find-and-replace with backreferences and groups
- Search — filter code or data by pattern
Decoding JWT Tokens
JSON Web Tokens (JWTs) are used everywhere for authentication and information exchange. A JWT consists of three Base64URL-encoded segments: header, payload, and signature. The JWT Decoder decodes the header and payload instantly so you can inspect claims like user ID, expiration time, and issuer. Note that decoding only reads the data — it does not verify the signature.
Converting Timestamps
Unix timestamps (seconds since January 1, 1970) are the standard way computers store time, but they are not human-readable. The Timestamp Converter converts Unix timestamps to formatted date strings and back. It supports both seconds and milliseconds, and shows the result in UTC and local time.
Formatting and Minifying HTML
Raw HTML — especially from email templates, CMS exports, or framework output — can be a mess of unindented tags. The HTML Formatter and Minifier beautifies ugly HTML with proper indentation, or compresses it by removing whitespace for production use. This is particularly useful when debugging template output or cleaning up copied markup.
Other Useful Code Tools
The JSON Formatter is perfect for API response debugging, and the URL Encoder/Decoder helps when working with query parameters and form data.