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Developer Tools

Developer Tools

Formatters, generators, and encoders for everyday development work.

All tools

Handiwork’s developer tools cover the small but frequent tasks that interrupt a coding session: formatting JSON, generating a UUID, hashing a string, comparing two blocks of text, decoding a cron expression, or checking color contrast for WCAG accessibility. Each one is focused on doing a single job quickly so you can get back to building.

Everything runs client-side in your browser, which keeps snippets, tokens, and config data private. No installs, no API keys, no rate limits — just open a tool and use it.

JSON Formatter

Beautify, validate, and minify JSON with syntax highlighting.

DeveloperOpen

UUID Generator

Generate random UUID v4 and v1 identifiers instantly.

DeveloperOpen

Hash Generator

Generate SHA-1, SHA-256, SHA-384, and SHA-512 hashes from any text.

DeveloperOpen

Markdown to HTML Previewer

Write Markdown and preview rendered output or HTML source live in your browser.

DeveloperOpen

Diff Checker

Compare text online, find line differences, ignore case or whitespace, and copy or download the diff.

DeveloperOpen

IP & Subnet Calculator

Convert IPv4 addresses, calculate CIDR subnets, and expand or compress IPv6 with live results.

DeveloperOpen

UTM Link Builder

Build campaign tracking URLs with utm_source, utm_medium, utm_campaign, and more.

DeveloperOpen

Opengraph Checker

Check a URL’s Open Graph and Twitter Card tags, see what’s missing, and preview how it looks when shared on Facebook, X, and Google.

DeveloperOpen

Cron Expression Explainer

Decode cron schedules into plain English with a field-by-field breakdown.

DeveloperOpen

Keyboard Tester

Test keyboard events with live key details, layout progress, shortcut capture, and copyable key history.

DeveloperOpen

Regex Tester

Build and debug regular expressions with live match highlighting, capture groups, and flag toggles.

DeveloperOpen

JWT Decoder

Decode and inspect a JSON Web Token’s header and payload, with expiry times in human-readable form.

DeveloperOpen

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