Free Developer Tools

Format, minify, validate, copy, and clean large JSON payloads entirely inside your browser.

Validate JSON syntax locally, find parse errors, and format valid JSON without uploading payloads.

Decode JWT headers and payloads locally in your browser with pretty-printed JSON and no signature verification.

Test JavaScript regular expressions locally with g, i, and m flags, match highlighting, counts, and friendly errors.

Format SELECT, INSERT, UPDATE, and DELETE SQL locally with readable clause breaks and indentation.

Format, minify, and validate XML locally in your browser with readable output and helpful parse errors.

Convert YAML to pretty JSON and JSON to readable YAML locally with validation errors and copy-ready output.

Write Markdown and see a sanitized live HTML preview locally with support for headings, lists, tables, quotes, links, and code blocks.

Generate fake names, emails, phone numbers, usernames, addresses, and UUIDs locally for mockups, demos, and test data.

Validate and compare two JSON values locally to find added, removed, and changed fields with path-level results.

Generate title, description, keywords, author, canonical, robots, language, viewport, and charset meta tags locally.

Create a robots.txt file with user-agent, allow, disallow, sitemap, and crawl-delay rules using browser-only processing.

Generate Open Graph and Twitter card tags for titles, descriptions, URLs, images, and site names locally in your browser.

Build campaign tracking URLs with source, medium, campaign, term, and content parameters locally in your browser.

Generate JSON-LD for Article, FAQPage, LocalBusiness, Product, WebSite, and BreadcrumbList schema types locally.

Create a valid sitemap.xml file from manual URL entries with priority, change frequency, and last modified fields.

Minify, beautify, copy, and download HTML locally with size and compression reporting.

Minify, compress, beautify, copy, and download CSS locally with character counts and compression reporting.

Minify, compress, beautify, copy, and download JavaScript locally without executing code or using eval.

Encode text or files to Base64 Data URIs and decode Base64 strings locally with UTF-8 safety and image previews.

Generate one or many UUID v4 identifiers instantly in your browser using secure client-side randomness.

Encode and decode URLs, query strings, and percent-encoded text instantly in your browser.

Generate downloadable QR codes locally for links, text, emails, phone numbers, and contact details.

Scan QR codes from uploaded images or your camera locally in the browser with copyable decoded results.

Convert Unix timestamps to readable dates and readable dates back to timestamps in local time or UTC.

Generate MD5, SHA1, SHA256, and SHA512 hashes from text locally in your browser.

Format, beautify, minify, copy, and inspect HTML character counts locally without uploading or executing code.

Extract source, medium, campaign, term, and content UTM parameters from a URL and copy them as JSON locally.

Validate JSON-LD syntax, detect schema types, review required and recommended fields, and pretty-print markup locally.

Generate one or many random whole numbers within a custom range, with an optional unique-numbers mode.

Decode QR codes from local image files, preview the source, and copy the extracted text without uploading the image.

Create Code 128 and EAN-13 barcodes locally, customize bar dimensions, and download SVG output.

Read supported barcode formats from local images using the browser Barcode Detector API with no upload fallback.

Parse URLs into protocol, origin, host, port, pathname, query parameters, hash, and username locally.

Normalize a domain and parse pasted WHOIS output into registrar, dates, nameservers, and status details without a live lookup.

Generate alternate-language link tags with validated locale codes, absolute URLs, and an optional x-default URL.

Normalize an absolute URL, optionally remove query parameters and fragments, and generate a canonical link tag.

Validate pasted or uploaded sitemap XML syntax, root type, loc URLs, duplicates, and URL-count limits locally.

Analyze a manually entered redirect chain for invalid URLs, status codes, loops, excessive hops, and final response status.

Validate robots.txt groups, directives, rules, sitemap URLs, ordering, and unknown directives locally.

Validate canonical UUID strings, normalize letter case and braces, and inspect version and variant.