meta-dump.js

( function () {

var els = [].slice.call( document.querySelectorAll( 'title, meta[content][name], meta[content][property]' ) ); 
var meta = {}; 
els.forEach( function ( el ) { 
    if ( el.nodeName.toLowerCase() === 'title' ) { 
        meta.title = el.textContent; 
    } else {
        meta[ el.getAttribute( 'property' ) || el.getAttribute( 'name' ) ] = el.getAttribute( 'content' );
    }
} );
return meta;

} () );