Free Developer & Text Tools

About these tools

The Dev section collects the utilities developers and writers reach for daily: format and validate JSON with real error messages, test JavaScript regular expressions with live highlighting, encode and decode Base64 with proper Unicode handling, count words and estimate reading time, convert text between naming conventions, diff two texts line by line, and compose cron schedules with a plain-English readback.

Every tool runs locally in your browser. Nothing you paste — code, configs, drafts — is uploaded, logged, or stored, which matters when the text you're working with is proprietary.

The tools use native engines where possible: JSON validation matches JavaScript's own parser, and the regex tester runs the actual JavaScript RegExp engine, so what works here works in your code.

For encoding work, match the tool to the layer: the URL Encoder handles query strings and path segments, the HTML Encoder escapes characters that would otherwise break markup or open an injection hole, and Base64 covers binary-to-text for data URLs and headers. The JSON Formatter and JWT Decoder both read structured payloads, but only the JWT tool splits header, claims, and signature and decodes the timestamps. Reach for the Diff Checker when you need to see what changed between two versions, the Regex Tester when you need to see what a pattern actually matches, and the Text Cleaner when the problem is invisible — smart quotes, non-breaking spaces, and stray whitespace that survived a copy-paste.

Frequently asked questions