UD5 Toolkit
Device Pixel Ratio Checker - Online See Your DPR
Display your screen's current devicePixelRatio. See how it changes when you zoom. Useful for high‑res image decisions.
Tag: JavaScript typeof Checker
12+ toolsSkip Link Validator - Online See Bypass Blocks
Check if your site has a visible and functional skip navigation link. Key for keyboard‑only users.
GeoJSON Validator - Online Check Geometry & Properties
Paste a GeoJSON object and validate its structure. Catch missing coordinates, wrong types, and feature errors. Local.
Simple Uptime Monitor - Online Check Website Status from Your Browser
Enter a URL and click to check if it's reachable from your browser (CORS-limited, uses no-cors fetch). Quick manual test. Local only.
Screen Color Depth Checker - Online 8‑bit vs 16‑bit
See your monitor's color depth and pixel depth. Detect if HDR or wide gamut is available using media queries.
HTML Validator Lite - Online Check Syntax Errors
Paste HTML and detect unclosed tags, invalid nesting, and duplicate IDs. Lightweight client‑side validation.
Number to English Words - Online Write Out Checks
Enter any number up to trillion and get the English word representation. For filling out checks or legal documents.
SQL Syntax Validator - Online Quick Check
Paste your SQL query and check for basic syntax errors. Highlights missing commas, wrong keywords. Local analysis.
Semantic Versioning Validator - Check Semver Syntax
Validate if a version string follows SemVer 2.0.0. Also sort and compare versions. Developer tool.
Weak Password Dictionary Check - Online Top 10k List
Compare your password against a built‑in list of the 10,000 most common passwords. Instant warning if it appears.
Base64 String Validator - Online Check Valid Encoding
Paste a string and verify if it is valid Base64. Auto‑detects padding issues and character errors. Quick dev check.
ISBN Validator - Online Check ISBN‑10 & ISBN‑13
Validate ISBN‑10 and ISBN‑13 numbers and compute their check digits. Useful for booksellers and libraries. All local.