一、背景介绍
在 2000 年代初期，标题元素（H1、H2、H3）是实际的排名因素。如果您想排名，必须在标题元素中添加关键字。
但多年来情况并非如此。然而，担心标题标签中的关键字是一种常见的 SEO 做法。
“死记硬背”这个词的意思是机械地、出于习惯地做某事，而不加思考。将关键字添加到标题标签已成为一种死记硬背的 SEO 做法。这样做不是因为它有用，而是因为它是一种习惯。查看大多数查询中排名靠前的网站，您很可能不会看到网站在标题元素中包含关键字。
二、google专家的最新解释
Google 的 John Mueller 清楚地解释了 Google 如何使用 H1、H2、HTML 标题。这个解释显示了标题元素在排名中的作用以及你应该如何使用它们。
（一）约翰穆勒反驳旧的 SEO 做法
穆勒首先反驳了机械地将关键字添加到标题中的死记硬背和过时的 SEO 做法，认为标题标签仍然是排名因素。他说标题被高估了，并暗示有些人对标题的过度思考超过了必要的程度。
他原话是这样说的：
I think in general, headings are a bit overrated in the sense that it’s very easy to… get pulled into lots of theoretical discussions on what the optimal headings should be.
John Mueller 继续解释说，谷歌以他们本来的方式阅读标题，这是为了理解标题后面段落的主题是什么。
We do use headings when it comes to search. But we use them to better understand the content on the pages.
过时和死记硬背的 SEO 认为 H1 标题作为排名因素比 H2 标题更重要，H2 标题比 H3 标题更重要（作为排名因素）等等。死记硬背的 SEO 信念是，将最重要的关键字放在最高级别的标题中，将不太重要的关键字放在较低级别的标题元素中。
标题标签的相对重要性，即 H1 比 H2 更重要，在 15 年前曾经是一个真正的排名因素。
约翰·穆勒解释说，情况不再如此：
So… this question of… how should I order my H1, H2, H3, headings and what should the content be, that’s something from my point of view isn’t really that relevant.
显然，标题标签可以指示信息的层次级别，即几个 H3 标题是前一个 H2 的子主题。这不是排名因素问题。这是对 Web 文档的正确组织。
穆勒似乎要解决的是死记硬背的 SEO 理念，即一个标题比另一个标题更重要的是排名目的。
三、如何正确使用h1,h2,h3
John Mueller 需要花时间解释的是，标题标签对于解释文本的内容很有用，这就是标题标签的目的。
But rather, what we use these headings for is well we have this big chunk of text or we have this big image and there’s a heading above that, therefore maybe this heading applies to this chunk of text or to this image.
So it’s not so much like there are five keywords in these headings, therefore this page will rank for these keywords but more, here’s some more information about that piece of text or about that image on that page.
And that helps us to better understand how to kind of frame that piece of text, how to frame the images that you have within those blocks. And with that it’s a lot easier to find… the right queries that lead us to these pages.
四、标题标签不再是排名因素？
几十年来，标题标签一直是排名因素的前十名。但是，如果您查看搜索引擎结果页面 (SERP)，您会发现情况并非如此。任何反对的人都是在否认他们眼前存在的东西。
标题标签的正确使用已经改变。正确的用途是帮助搜索引擎了解内容的含义。而已。
穆勒解释说，标题中的关键字不是排名所必需的：
So it’s not so much that suddenly your page ranks higher because you have those keywords there. But suddenly it’s more well Google understands my content a little bit better and therefore it can send users who are explicitly looking for my content a little bit more towards my page.
如何正确使用：
“So obviously there’s a little bit of overlap there with regards to… Google understanding my content better and me ranking better for the queries that I care about. Because if you write about content that you want to rank for which probably you’re doing, then being able to understand that content better does help us a little bit.
But it’s not that suddenly your page will rank number one for competitive queries just because you’re making it very easy for Google to understand your content.
So with that said, I think it’s useful to… look at the individual headings on a page but… don’t get too dug down into all of these details and variations and instead try to find a way to make it easy for people and for scripts to understand the content and kind of the context of things on your pages.
五、案例
标题用h1, 小标题用h2,
参见：https://fitsmallbusiness.com/how-to-open-a-juice-bar/
参考：https://www.searchenginejournal.com/heading-tags-for-seo/341817/