UD5 Toolkit
Photo Print Resolution Checker – Online DPI Maximum Size
Enter megapixels and desired DPI to see the maximum print size without upscaling. Quick quality check.
Online Checkers & Validators
10+ toolsCar Seat Fit Checker – Online Height/Weight vs. Seat Limits
Enter child's stats and compare to typical rear-facing, forward-facing, and booster seat requirements. Reference tool.
JSON Deep Diff Checker - Online Compare & Highlight Changes
Compare two JSON objects and see added, removed, or changed keys. Visual tree view with color highlighting. Handles nested structures. Local processing.
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.
Blood Donation Eligibility Checker - Online Quick Questionnaire
Answer a short questionnaire based on common deferral criteria (travel, medication, tattoos) to see if you may be eligible to donate blood. Educational only.
HTTP Security Header Checker - Online HSTS, CSP, X-Frame Analysis
Paste response headers string and get a security audit. Check presence and configuration of key security headers. Local analysis.
Basic Grammar Checker - Online Free Writing Assistant
Identify common grammar mistakes (subject-verb agreement, tense, articles) with simple rule-based analysis. Explanations provided. Not AI, purely rule-based and local.
Emoji Version Checker – Online See Unicode Support per OS
Enter an emoji or browse to see which Unicode version introduced it and whether older OS versions might fail.
Opened Paint Freshness Checker – Online Smell & Consistency Guide
Enter the approximate age of opened paint and answer visual/olfactory questions to see if it's still usable. Reduce waste.
Fish Disease Symptom Checker – Online Visual Diagnosis
Select visual symptoms (spots, fin rot, swelling) to narrow down possible freshwater fish diseases.