Free Online Developer Tools
These are the small utilities that interrupt real work: an API returned one long line of JSON, a log row has an epoch timestamp in it, a stylesheet needs minifying before it ships, or a fixture needs a UUID. Each tool here handles one of those, shows its output immediately, and lets you copy it straight back into your editor.
29 tools in this category. All free, no sign-up.
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JSON Formatter & Validator Online
Prettify and format ugly JSON code with customizable indentation. Instantly beautify minified JSON.
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Unix Timestamp Converter
Convert Unix timestamp to date or date to timestamp. Supports seconds and milliseconds format.
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CSS Minifier Online
Compress CSS code by removing whitespace and comments. Reduce file size for faster website loading.
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UUID Generator
Generate unique identifiers (UUIDs) for development. Support for UUID v1 and v4 formats.
All developer tools
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UUID Generator
Generate unique identifiers (UUIDs) for development. Support for UUID v1 and v4 formats.
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Website Down Checker
Ping a website to check if it is online and responding. Check HTTP, HTTPS, and DNS status.
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Screen Resolution Tester
Check current viewport size and screen resolution. View device information and browser det...
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URL Decoder
Decode URL-encoded text back to normal readable format. Convert %20 and + back to spaces i...
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Bcrypt Hash Generator
Generate secure bcrypt password hashes with adjustable cost factor. Includes password veri...
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HTML Beautifier
Format messy HTML code with proper indentation. Beautify minified or unformatted HTML inst...
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SQL Formatter
Prettify SQL queries with proper indentation and formatting. Make complex queries readable...
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User Agent String
Show your browser user agent string with detailed browser, OS, and device information.
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What Is My IP
Show your public IP address instantly. View detailed information about your IP location an...
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Robots.txt Generator
Create robots.txt file with crawler allow/disallow rules. Generate rules for search engine...
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XML to JSON Converter
Convert XML data to JSON format easily. Preserve attributes and convert complex XML struct...
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Markdown to HTML Converter
Convert Markdown syntax to HTML code instantly. Preview rendered output or view HTML sourc...
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Whois Lookup
Check domain registration information. View registrar, registration dates, name servers, a...
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URL Encoder & Decoder
Encode text for URLs with %20 style encoding. Also decode URL-encoded text back to readabl...
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JSON Validator
Check if your JSON is error-free. Instantly validate JSON syntax and structure with detail...
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HTML to Markdown Converter
Convert HTML code to Markdown syntax. Perfect for converting web content to markdown forma...
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MD5 Hash Generator
Create MD5 hash of any string. Also generates SHA-1 and SHA-256 hashes for comparison.
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Open Graph Generator
Create Open Graph meta tags for social media sharing. Generate Facebook, Twitter, LinkedIn...
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QR Code Reader
Read QR codes from uploaded images or webcam. Decode QR codes instantly.
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JavaScript Minifier
Compress JavaScript code to reduce file size. Remove whitespace, comments, and optimize fo...
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Sitemap Generator
Create XML sitemap from list of URLs. Generate sitemap.xml for search engines.
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Barcode Generator
Create UPC/EAN/CODE128 barcodes. Generate barcodes in SVG, PNG, or Canvas format.
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SHA-256 Hash Generator
Create secure SHA-256 hash of any string. Also generates SHA-512, SHA-1, and MD5 for compa...
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Unix Timestamp Converter
Convert Unix timestamp to date or date to timestamp. Supports seconds and milliseconds for...
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CSS Minifier
Compress CSS code by removing whitespace and comments. Reduce file size for faster website...
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Meta Tag Generator
Create SEO meta tags for your website. Generate title, description, keywords, canonical UR...
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JSON to XML Converter
Convert JSON data to XML format with customizable options. Perfect for API integration and...
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JSON Formatter
Prettify and format ugly JSON code with customizable indentation. Instantly beautify minif...
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Htaccess Redirect Generator
Create .htaccess redirect code for 301, 302, and 307 redirects. Generate single or bulk re...