Purpose: Demonstrates development-time validation that catches common errors when
partial templates accidentally contain layout elements (<html>, <body>)
or duplicate semantic landmarks (<header>, <footer>).
Open your browser's DevTools console to see styled warnings when swapping problematic content.
validationpartial templatesdeveloper tools
Configuration
Swap Target
This is the swap target. Content will be swapped here.
Current time:
Test Scenarios
Critical Issues (Always Detected)
These represent serious errors where a server returns a full page instead of a partial.
Structural Issues (Standard/Strict Mode)
These may cause duplicate semantic landmarks, affecting accessibility.
Valid Partial Content
These are valid partial templates that should pass validation.
Validation Log
Waiting for swap operations...
Manual Validation API
You can also validate HTML content manually without swapping: