H tags semantic order SEO check

copy-to-console-of-browser

(function() {
    const headings = [...document.querySelectorAll('h1, h2, h3, h4, h5, h6')];
    let isOrdered = true;
    let lastLevel = 0;

    // Should have at least one H1
    const hasH1 = headings.some(heading => heading.tagName === 'H1');
    if (!hasH1) {
        console.warn("Missing H1 heading");
        isOrdered = false;
    }

    headings.forEach((heading, index) => {
        const currentLevel = parseInt(heading.tagName[1], 10);

        // Check if the headings are ordered correctly
        if (currentLevel > lastLevel + 1 && !(lastLevel === 3 && currentLevel === 2)) {
            console.warn(`Error in the heading element: ${heading.tagName} at index ${index + 1}`);
            isOrdered = false;
        }

        lastLevel = currentLevel;
    });

    // Check if the headings are ordered correctly
    if (isOrdered) {
        console.log("The headings are ordered correctly.");
    } else {
        console.warn("The headings are not ordered correctly.");
    }
})();