15 Free Developer Tools That Replace a Dozen Browser Tabs

Every developer has the same dozen "utility" tabs open. Here's the consolidated kit — each tool runs locally, so API responses and tokens never leave your machine.

JSON, the daily driver

Format minified API responses with the JSON formatter, catch syntax errors with the validator, and shrink payloads with the minifier. Moving data into spreadsheets? JSON to CSV and CSV to JSON handle both directions.

Encoding and decoding

Base64 encode and decode (Unicode-safe), URL-encode query parameters, and inspect auth tokens with the JWT decoder — header and payload, decoded locally, no token ever transmitted.

Hashes and identifiers

Generate MD5, SHA-256 and bcrypt hashes for checksums and password fields, and v4 UUIDs for database keys. (Reminder: MD5 is fine for checksums, never for passwords — that's what bcrypt is for.)

Regex without the trial-and-error deploy

The regex tester shows live matches against sample text — test the pattern here, not in production logs.

Formatting and minification

Tidy queries with the SQL formatter, shrink assets with the CSS, JS and HTML minifiers, and preview README files with the Markdown previewer.

The little ones you'll use weekly

Unix timestamp converter for logs and APIs, color converter for HEX↔RGB↔HSL, text↔hex for debugging encodings, and the Luhn validator for testing payment forms with valid-format numbers.