Add custom page title and meta description only product pages in shopify

Go to the theme.liquid file in editor and replace these lines with your existing title and meta description code.

<!---- Title and description ---->
<title>
{% if product %}
Buy {{ product.title }} Online India – {{ shop.name }} {% else %}
{{ page_title }} {% if current_tags %} | tagged "{{ current_tags | join: ', ' }}"{% endif %}{% if current_page != 1 %} | Page {{ current_page }}{% endif %}{% unless page_title contains shop.name %} | {{ shop.name }}{% endunless %}
{% endif %}
</title>

{% if product %}
<meta name="description" content="Buy {{ product.title }} at {{ shop.name }}. Enjoy best deals, free shipping, offers and much more on it. Shop Now!">
{% else %}
{% if page_description %}
<meta name="description" content="{{ page_description | escape }}">
{% endif %}
{% endif %}

Read more