Developer Tools

Fast, server-free tools for everyday development tasks like JSON formatting, regex testing, and JWT decoding.

What's in this category?

The tools form a few clusters by job. On the JSON side, the Formatter, Validator and Beautifier help you read an API response or find the error in a config file, while JSON to CSV and CSV to JSON move data between tables and code. HTML, CSS and JavaScript each get a pair going in opposite directions: formatters make compact code readable, and minifiers strip whitespace from files headed to production.

The rest are encoding and debugging helpers. The JWT Decoder shows what a token carries, the Base64 Decoder turns encoded text back into plain text, and the Hash Generator produces SHA-family digests. The Regex Tester lets you try a pattern on real data, the Cron Expression Generator writes a scheduling line for you, and the UUID Generator gives you unique IDs for test records.

Which tool for which job?

To inspect a one-line API response, use the JSON Formatter. If you only need to know whether it parses, the JSON Validator is quicker.
To open a product list in Excel or send it to a client as a table, use JSON to CSV. To turn a spreadsheet into test fixtures, use CSV to JSON.
When a login session misbehaves, the JWT Decoder shows the token's expiry time and the claims it carries.
Try the email or phone pattern you wrote for form validation against real samples in the Regex Tester.
For a backup script that should run at the same time every night, use the Cron Expression Generator.
To confirm that a config text is identical in two environments, compare short digests from the Hash Generator.

Things to keep in mind

The JWT Decoder does not verify the signature. It only makes the contents readable. Whether a token is valid is decided by server-side verification.
Base64 is encoding, not encryption. A password or key stored as Base64 can be decoded by anyone.
Always keep the readable source next to a minified file. Editing minified output by hand is slow and error-prone.
Cron runs in the time zone of the machine that executes it. Check whether your job will fire on local time or UTC.

Newly added tools

URL Encoder / Decoder: Percent-encode or decode URLs and query parameters.
Unix Timestamp Converter (Epoch): Convert Unix timestamps to dates and dates to timestamps, in seconds or milliseconds.
Color Code Converter (HEX, RGB, HSL): Convert between HEX, RGB and HSL colour codes instantly.
Number Base Converter (Binary, Decimal, Hex): Convert numbers between binary, octal, decimal and hexadecimal.