Developer Tools
Developer Tools
Formatters, generators, and encoders for everyday development work.
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.
UUID Generator
Generate random UUID v4 and v1 identifiers instantly.
Hash Generator
Generate SHA-1, SHA-256, SHA-384, and SHA-512 hashes from any text.
Markdown to HTML Previewer
Write Markdown and preview rendered output or HTML source live in your browser.
Diff Checker
Compare two texts line by line with live highlighting and change stats.
IP & Subnet Calculator
Convert IPv4 addresses, calculate CIDR subnets, and expand or compress IPv6 with live results.
UTM Link Builder
Build campaign tracking URLs with utm_source, utm_medium, utm_campaign, and more.
Cron Expression Explainer
Decode cron schedules into plain English with a field-by-field breakdown.
Regex Tester
Build and debug regular expressions with live match highlighting, capture groups, and flag toggles.
JWT Decoder
Decode and inspect a JSON Web Token’s header and payload, with expiry times in human-readable form.
Color Contrast Checker
Check the contrast ratio between two colors and test WCAG AA/AAA accessibility compliance.