UD5 Toolkit
XML Formatter & Validator - Free Online XML Beautifier
Easily format, validate, and beautify XML documents. Minify XML data with a single click. All processing happens locally in your browser for maximum privacy.
XML Sitemap Validator - Online Check Structure & Errors
XML Sitemap Validator
Validate your XML sitemap structure, detect errors, check protocol compliance, and ensure search engines can properly crawl your URLs.
Due to CORS restrictions, fetching remote sitemaps may fail. If so, please copy the sitemap content and use the Paste XML tab.
Frequently Asked Questions
What is an XML Sitemap?
An XML sitemap is a file that lists all important URLs of your website, helping search engines like Google, Bing, and Yahoo discover and index your content more efficiently. It follows the Sitemaps protocol standard.
How do I find my sitemap?
Common locations include /sitemap.xml, /sitemap_index.xml, or check your robots.txt file (e.g., https://yoursite.com/robots.txt) for a Sitemap: directive. CMS platforms like WordPress often generate sitemaps automatically via plugins like Yoast SEO or Rank Math.
What are common sitemap errors?
Frequent issues include: invalid XML syntax (unclosed tags, special characters not escaped), missing <loc> elements, incorrect namespace declarations, invalid date formats in <lastmod>, out-of-range priority values (must be 0.0–1.0), and duplicate URLs.
What are the size limits?
A single sitemap file must not exceed 50MB (uncompressed) and can contain at most 50,000 URLs. If your site exceeds these limits, use a Sitemap Index file to split URLs across multiple sitemap files.
What is a Sitemap Index?
A Sitemap Index file (root element <sitemapindex>) references multiple individual sitemap files. Each <sitemap> entry contains a <loc> pointing to a child sitemap. This allows large websites to organize URLs across many files while staying within protocol limits.
How to submit a sitemap to search engines?
Submit via Google Search Console (Index → Sitemaps), Bing Webmaster Tools, or add a Sitemap: directive in your robots.txt. You can also ping search engines directly: https://www.google.com/ping?sitemap=YOUR_SITEMAP_URL.
How often should I update my sitemap?
Update your sitemap whenever you add, remove, or significantly modify important pages. For dynamic sites (e.g., e-commerce, news), consider automated daily regeneration. Use the <lastmod> and <changefreq> tags to signal update frequency to crawlers.
Does a valid sitemap guarantee indexing?
No. A valid sitemap helps search engines discover your URLs, but indexing depends on content quality, crawl budget, canonical signals, and other ranking factors. Always pair a clean sitemap with proper internal linking and high-quality content for best results.
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HTML Validator Lite - Online Check Syntax Errors
Paste HTML and detect unclosed tags, invalid nesting, and duplicate IDs. Lightweight client‑side validation.
YAML Validator & Formatter - Online Check Syntax
Validate YAML syntax with line‑by‑line error messages. Also format messy YAML into clean, indented output. All in your browser.
ETag & Last‑Modified Validator - Online Check Cache Headers
Send conditional requests to a URL and verify that the server correctly handles ETag and If‑None‑Match. Audit caching.
SQL Syntax Validator - Online Quick Check
Paste your SQL query and check for basic syntax errors. Highlights missing commas, wrong keywords. Local analysis.
JavaScript Syntax Validator - Online Check Errors
Paste JavaScript and catch syntax errors instantly with line numbers. Lightweight pre‑commit check. Local.
DNS Record Syntax Checker - Online Validate BEFORE Publishing
Paste any DNS record and check if its format is valid for the selected record type (A, AAAA, CNAME, MX, TXT, SRV). Prevents typos.
Crypto Address Format Checker - Online Validate Wallet
Paste a Bitcoin, Ethereum, or other crypto wallet address and quickly verify its format and checksum. No connection to blockchain.
Test Credit Card Validator - Online Luhn Check & Issuer
Paste a test card number to verify Luhn algorithm, identify issuer (Visa, MC), and check length. No real data.
Web Performance Checklist - Online Quick Audit
Answer questions about your page (image size, caching, fonts) and get a tailored list of optimization tips. Manual audit helper.
RegEx Tester - Online Regular Expression Builder & Matcher
Build and test regular expressions against sample text. Real-time match highlighting, capture groups display, and flavor options. All inside your browser.
JSON Formatter & Validator - Online JSON Beautifier
Online JSON formatting and validation tool, supporting JSON minify/beautify, syntax highlighting, and error locating. Data processed locally in browser for security.
Luggage Size Checker - Online Airline Carry-On Compliance Tool
Enter your bag dimensions and compare against major airline carry-on and checked limits. Visual pass/fail gauge. Avoid gate fees.
Color Contrast Checker - Online WCAG Accessibility Validator
Check the contrast ratio between foreground and background colors to ensure web accessibility compliance. Get WCAG 2.1 AA/AAA pass/fail results instantly.
UPC Barcode Validator - Online Check Digit & EAN
Enter a UPC or EAN barcode number and validate the check digit. See if it's a real product code. Local calculation.
Assertive Statement Composer – Online I-Statements Tool
Build 'I feel... when... because...' statements interactively. Improve communication in relationships. Local only.
Bulk Color Contrast Checker - Online WCAG Validation
Paste a list of foreground/background color pairs and instantly see which pass AA/AAA. Perfect for checking entire style guides.
Colorblind-Safe Palette Builder - Online Check & Generate Schemes
Build a palette and simulate how it appears to various color deficiencies. Also generate pre-vetted accessible palettes. Local processing.
Pet Sitting Checklist – Online Generate Care Sheet for Sitter
Fill in feeding, walking, medication details and generate a clear care sheet for your pet sitter. Print or share.
Meta Tag Generator - Online SEO & Social Meta Tags Creator
Generate comprehensive HTML meta tags for SEO and social sharing (Open Graph, Twitter Cards). Copy ready-to-use code. Boost your search visibility.
Camping Gear Checklist – Online Custom by Trip Type
Generate a camping checklist based on trip style (car, backpacking, glamping). Check off items. Fully local.
Lumber Calculator – Online Board Feet & Material Lists
Calculate board feet for dimensional lumber and generate a cut list with waste factor. Quick carpentry tool.
Palindrome Checker - Online Test Words & Sentences
Check if a word or phrase is a palindrome (reads same forward and backward). Live validation and fun facts.
color‑scheme Meta Generator - Online Dark/Light Opt‑in
Generate the <meta name='color‑scheme'> tag and CSS property to enable native dark/light rendering. Quick copy.
Math Expression Evaluator - Online Type & Calculate
Type a mathematical expression like 'sqrt(16)+sin(pi/2)' and get the result instantly. Supports popular functions. Local.
Houseplant Problem Identifier – Online Leaf Symptoms
Click on leaf symptoms (yellow, brown tips, spots) to diagnose common houseplant issues and solutions.
Virtual Keyboard Tester - Online Check All Keys Functionality
Press keys on your physical keyboard and see them highlighted on a virtual keyboard. Detects multi-key rollover. Quick hardware check.
Compost Ratio Calculator – Online Brown/Green Balance Tool
Adjust material types (leaves, grass) to achieve the ideal 30:1 C:N ratio. Improve compost bin performance. Local only.
HTML Email Signature Builder - Online Professional Footer Creator
Create a polished HTML email signature with your photo, links, and company details. Live preview and copy HTML to clipboard. Works with Gmail, Outlook, Apple Mail.
Pet Body Condition Score Estimator – Online Weight & Rib Check
Visual chart and questionnaire to estimate pet obesity risk. Combines weight, breed, and palpation guide.