JavaScript Syntax Validator - Online Check Errors
Paste JavaScript and catch syntax errors instantly with line numbers. Lightweight pre‑commit check. Local.
UD5 Toolkit
Check & validate your SQL queries instantly online. Supports multiple dialects patterns.
Enter SQL and click Validate
Paste JavaScript and catch syntax errors instantly with line numbers. Lightweight pre‑commit check. Local.
Paste HTML and detect unclosed tags, invalid nesting, and duplicate IDs. Lightweight client‑side validation.
Validate YAML syntax with line‑by‑line error messages. Also format messy YAML into clean, indented output. All in your browser.
Paste any DNS record and check if its format is valid for the selected record type (A, AAAA, CNAME, MX, TXT, SRV). Prevents typos.
Quickly test SQL JOIN syntax (INNER, LEFT, RIGHT, FULL) with a sample database schema. Check logic and see conceptual result set without a real DB. Local only.
Paste your sitemap XML and check for missing namespaces, invalid URLs, or size limit violations. Keep your SEO healthy.
Send conditional requests to a URL and verify that the server correctly handles ETag and If‑None‑Match. Audit caching.
Paste a Bitcoin, Ethereum, or other crypto wallet address and quickly verify its format and checksum. No connection to blockchain.
Easily format, validate, and beautify XML documents. Minify XML data with a single click. All processing happens locally in your browser for maximum privacy.
Build and test regular expressions against sample text. Real-time match highlighting, capture groups display, and flavor options. All inside your browser.
Answer questions about your page (image size, caching, fonts) and get a tailored list of optimization tips. Manual audit helper.
Paste a test card number to verify Luhn algorithm, identify issuer (Visa, MC), and check length. No real data.
Check if a word or phrase is a palindrome (reads same forward and backward). Live validation and fun facts.
Enter any phrase and instantly see if it's a palindrome, ignoring spaces and punctuation. Fun for word nerds.
Enter a UPC or EAN barcode number and validate the check digit. See if it's a real product code. Local calculation.
Online JSON formatting and validation tool, supporting JSON minify/beautify, syntax highlighting, and error locating. Data processed locally in browser for security.
Type a mathematical expression like 'sqrt(16)+sin(pi/2)' and get the result instantly. Supports popular functions. Local.
Build 'I feel... when... because...' statements interactively. Improve communication in relationships. Local only.
Fill in feeding, walking, medication details and generate a clear care sheet for your pet sitter. Print or share.
Paste a list of foreground/background color pairs and instantly see which pass AA/AAA. Perfect for checking entire style guides.
Select logical operators (AND, OR, XOR, NAND) and generate a complete truth table. Handy for digital logic.
Interactive ASCII table showing decimal, hex, octal, and binary codes for all standard and extended ASCII characters. A classic programmer reference.
Enter your bag dimensions and compare against major airline carry-on and checked limits. Visual pass/fail gauge. Avoid gate fees.
Paste tab‑separated or CSV data and instantly get a beautifully aligned Markdown table. Essential for documentation.
Check the contrast ratio between foreground and background colors to ensure web accessibility compliance. Get WCAG 2.1 AA/AAA pass/fail results instantly.
Take a perfectly fine phrase and insert realistic-looking typos. For pranks or testing spell‑checkers.
Press keys on your physical keyboard and see them highlighted on a virtual keyboard. Detects multi-key rollover. Quick hardware check.
Type a passage and see it appear in a realistic cursive font. Helps connect handwriting to digital text.
Convert between whole fruit, juice volume, and zest quantity. Never wonder how many lemons for 1/4 cup.
Convert currencies using a built‑in table of approximate fixed rates. Useful for quick estimates without live data. Local.