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Deprecated HTML Tags Checker

Scan a page for obsolete HTML: tags like font, center and marquee, presentational attributes, Flash embeds and an outdated doctype.

Fetching and analysing the page…

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Deprecated HTML Tags Checker - results and guide

What the Deprecated HTML Tags Checker checks

  • 28 obsolete elements, including font, center, marquee, strike, big, tt, frame and frameset
  • Presentational attributes such as bgcolor, align, cellpadding and hspace
  • Flash content in embed and object elements
  • A missing or legacy doctype
  • A missing lang attribute or character encoding
  • A modern replacement for everything it finds

What are deprecated HTML tags?

HTML has been cleaned up over the years. Elements that controlled appearance, such as <font>, <center> and <big>, were removed from the standard once CSS could do the same job better. Others, like <marquee>, <blink>, <frameset> and <applet>, were dropped because they caused accessibility or security problems.

Browsers still display most of them for the sake of old sites, but they are no longer required to, and support has already ended for several, including Java applets and Flash.

Does old HTML hurt SEO?

Deprecated tags are not a ranking factor, and Google will index a page that uses them. The cost is indirect. Old markup usually comes with table-based layouts that do not adapt to phones, with pages that are slow and heavy, and with poor accessibility. Those do affect how a page performs in search and how long visitors stay.

The doctype matters more than it looks. Without <!DOCTYPE html> on the first line, browsers switch to quirks mode and lay the page out by the rules of the 1990s, which produces inconsistent results between browsers. After cleaning up the markup, check the whole page with the On-Page SEO Checker.

How to use the Deprecated HTML Tags Checker

  1. Enter the address of the page you want to check. You can leave out https://.
  2. Press Scan HTML. The page is fetched from our servers, the way a search engine crawler would fetch it.
  3. Read the findings from top to bottom: problems first, then warnings. Each one says what to change.

Common problems and how to fix them

font and center tags

Remove the tags and set font-family, font-size, color and text-align in CSS. A class on the paragraph does the same job with less markup.

Frames and framesets

Rebuild the layout as normal pages with shared header and navigation. Content inside frames is hard to link to and to index.

bgcolor, align and cellpadding on tables

Move them to CSS: background-color, text-align and padding. Keep tables for tabular data and use flexbox or grid for layout.

Frequently asked questions

Are deprecated HTML tags bad for SEO?
Not directly. Google does not penalise them. They often come with slow, inaccessible, non-responsive pages, and those problems do hurt.
Will deprecated tags stop working?
Some already have: applet, keygen and Flash embeds no longer function. Others still render but can be removed from browsers at any time.
Should HTML emails be checked too?
No. Email clients still need table layouts and attributes like bgcolor and align. This check is meant for web pages.
What is the correct doctype?
A single line at the very top of the document: <!DOCTYPE html>. It is the HTML5 doctype and works in every browser.

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