Developer Tools
Formatters, generators, and encoders for everyday development work.
Beautify, validate, and minify JSON with syntax highlighting.
Generate random UUID v4 and v1 identifiers instantly.
Generate SHA-1, SHA-256, SHA-384, and SHA-512 hashes from any text.
Write Markdown and preview rendered output or HTML source live in your browser.
Compare text online, find line differences, ignore case or whitespace, and copy or download the diff.
Convert IPv4 addresses, calculate CIDR subnets, and expand or compress IPv6 with live results.
Build campaign tracking URLs with utm_source, utm_medium, utm_campaign, and more.
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.
Decode cron schedules into plain English with a field-by-field breakdown.
Test keyboard events with live key details, layout progress, shortcut capture, and copyable key history.
Build and debug regular expressions with live match highlighting, capture groups, and flag toggles.
Decode and inspect a JSON Web Token’s header and payload, with expiry times in human-readable form.
Generate TypeScript types from JSON with nested objects, arrays, and unions. Copy or download a .ts file.
Inspect URL components and decoded query parameters, including repeated keys, without opening the address.
Check whether GPTBot, ClaudeBot, PerplexityBot, Google-Extended, and other AI crawlers can access a page, and which robots.txt rule decides it.
Score a page out of 100 for AI search readiness (crawler access, indexability, readable HTML, structure, citations, and schema) with prioritized fixes.
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.