Performance tip. You can use the loading=lazy attribute to defer the loading of the image until the user scrolls to them.

Use the start attribute to change the starting point for your ordered lists.

You can use the <meter> element to display quantities. No JavaScript/CSS needed.

You can use the <fieldset> element to group several controls as well as labels (<label>) within a web form.

Pages opened with target="_blank" allow the new page to access the original’s window.opener. This can have security and performance implications. Include rel="noopener" or rel="noreferrer" to prevent this.

If you want to open all links in the document in a new tab, you can use <base> element:

To refresh your website’s favicon you can force browsers to download a new version by adding ?v=2 to the filename.

This is especially helpful in production to make sure the users get the new version.

Use the spellcheck attribute to define whether the element may be checked for spelling errors.

You can use <input type="range"> to create sliders.

You can use the details element to create a native HTML accordion.

You can use the <mark> tag to highlight text.

You can use the download attribute in your links to download the file instead of navigating to it.

Use the .webp image format to make images smaller and boost the performance of your website.

Use the poster attribute to specify an image to be shown while the video is downloading, or until the user hits the play button.

Use the type="search" for your search inputs and you get the “clear” button for free.