Developer tools

Browser-based utilities for everyday coding work — format JSON or XML, test regular expressions live, beautify or minify HTML/CSS/JS, generate UUIDs, and build cron expressions with a plain-English explanation. All offline-capable; nothing you paste leaves the page.

20 tools
📋JSON formatter & validator New
Pretty-print or minify JSON, with line/column-precise validation errors. Choose 2-space, 4-space, or tab indentation.
📋XML formatter New
Pretty-print and validate XML well-formedness via the browser's DOMParser. Preserves comments, CDATA, processing instructions.
🔍Regex tester New
Test JavaScript regular expressions live. Match highlighting, capture-group breakdown, and a replacement preview field.
💄Code minifier / beautifier New
Format or minify HTML, CSS, and JavaScript with one tool. Char-count stat shows your savings on each pass.
🆔UUID generator New
Generate cryptographically random UUID v4 values, single or in bulk. Lowercase, uppercase, hyphenated or braces format.
⏲️Cron expression generator New
Build a 5-field cron schedule from inputs. Plain-English explanation and the next 5 run times update live; common-pattern presets included.
🌐User-Agent parser New
Decode any User-Agent string into browser, version, OS, device type, rendering engine and bot identity. Plus a one-click "Use this browser" sample.
🕐Unix timestamp converter New
Convert epoch (seconds, milliseconds, micro, nano — auto-detected) to a human date in UTC and local time, with relative time. Date-to-timestamp the other way too.
🔁ENV to JSON New
Convert .env files to clean JSON. Handles quoted values, escape sequences, comments, and the Bash export prefix. Optional type coercion.
🔁Query string to JSON New
Parse URL query strings into JSON. Repeated keys become arrays; user[name]=… bracket notation builds nested objects.
🔁JSON to query string New
Convert a JSON object to a URL-encoded query string. Choose how arrays serialise (brackets, indices, repeat, comma) and pick bracket vs dot for nested keys.
🔁CSV to JSON New
Parse CSV (auto-detected delimiter — comma, tab, semicolon, pipe) into a JSON array. RFC 4180 quoted fields with embedded newlines and quotes are handled correctly.
🔁JSON to CSV New
Convert a JSON array to CSV. Auto-detects column union, optionally flattens nested objects to dot-keys, supports CRLF for Excel.
🏷️Meta tag generator New
Build a complete HTML <head> SEO snippet — title, description, canonical, robots, viewport, theme color, plus Open Graph and Twitter Card tags. Length counters flag overlong values.
❓FAQ schema generator New
Build JSON-LD FAQPage structured data. Add Q&A pairs and copy a script-tag-ready snippet for rich Google results.
🍞Breadcrumb schema generator New
Build JSON-LD BreadcrumbList with a live preview of how the trail will look. Each step gets a position, name and URL.
📝Markdown to HTML New
GitHub-flavoured Markdown with live rendered preview and switchable HTML source view. Tables, fenced code, task lists and more.
📖HowTo schema generator New
Build JSON-LD HowTo with steps, supplies, tools, total time and yield. Each step takes a name, instructions and optional image.
🌐OpenGraph tag generator New
Build og: + Twitter Card meta tags with a live link-preview card. Image dimensions, locale, alt text included.
🗺️Sitemap.xml generator New
Paste a URL list (or 4-column CSV with lastmod / changefreq / priority) and get a search-engine-ready XML sitemap. Direct download included.

Why browser-based?

Pasting code or data into a remote tool is a small but real privacy risk — internal API responses, customer records, secret tokens. Every tool here runs entirely in your browser via the platform's native APIs (JSON.parse, DOMParser, RegExp, crypto.getRandomValues) so nothing you paste is uploaded anywhere.

Need something not on this list? Drop us a note via the contact page.

Common questions

Do I need an internet connection?

You need it to load the page once. After that, everything runs locally — disconnect and the tools still work. The PWA install button (top-right on mobile) makes them work offline permanently.

Are these production-grade?

For everyday development and quick checks, absolutely. For build-pipeline use (e.g. minifying JS at deploy time) you'll still want dedicated tools like Prettier, terser, esbuild, etc. — they handle edge cases (template literals, ES2024 syntax, source maps) that simple browser-based tools don't.

Can I link to a specific input state?

Not yet. We're working on shareable URLs that encode the input as a query param.

Other categories

UtilityPassword, hash, encoder MathStatistics, probability ConversionUnits & numerals