Background
Whether it's an unfriendly link redirect tech stack or simply having too few links, both affect SEO performance.
Recently, I've noticed that crawling is very difficult for some client website pages, and new pages always take a long time to be discovered by crawlers. Without a coding background, I couldn't figure out where the problem was, since from a user behavior perspective, clicking links works fine. A few days ago, when checking AITDK's Links, I suddenly discovered that the number of clickable links on the page didn't match the displayed link count - the latter was much smaller. When I asked about the tech stack, it was location.href - oh no, there's definitely a problem. Page redirects are generally implemented in these three ways:
<a href="https://www.example.com">Visit Example Website</a>window.open("https://www.example.com/", "_blank");// This will redirect the current browser window to Example Page. window.location.href = "https://www.example.com";
After checking Google's technical documentation, JS-based dynamic injection redirects (the second and third methods) are not recommended because they may not be crawlable, meaning the link doesn't exist in Google's eyes. When I asked Qiufeng before, he mentioned that the third method is what frontend developers love to write, and indeed, many other client websites have the same problem.
| Redirect Method | SEO Friendly | Crawler Recognizable | Link Equity Passed | Recommendation |
|---|---|---|---|---|
<a> tag | ✅ High | ✅ Yes | ✅ Yes | 🟢 Highly Recommended |
window.open() | ❌ Low | ❌ No | ❌ No | 🔴 Not Recommended |
location.href | ❌ Low | ❌ No | ❌ No | 🔴 Not Recommended |
What is an <a> Tag?
<a href="https://www.example.com">Visit Example Website</a>The <a> tag in HTML defines a hyperlink, linking from one resource to another (not just pages - <a> tags can link to email addresses, images, videos, and other resources).
- If a hyperlink links from one resource to another resource on the same site, it's called an Internal Link
- If a hyperlink links from one resource to a resource on another website, it's called an External Link
Components of HTML <a> Tag
- Opening tag: Indicates the start of the <a> tag
- Tag attributes and attribute values: Specify the page the tag links to and affect user behavior when clicking the tag
- Anchor text: The text users click to access the link
- Closing tag: "</a>", indicates the end of the <a> tag
<a> Tag Attributes
Href
"Href" stands for "hypertext reference" and represents the resource the tag should link to. This attribute is mandatory in the tag, otherwise clicking the anchor text has nowhere to redirect.
Rel
"Rel" is short for "relationship" and represents the relationship between the current resource and the linked resource. A single Rel attribute can include multiple values. The values of this attribute include:
Noopener:
When users click to open a link in a new tab or window, the redirected page cannot control the current page; so the redirected page cannot redirect users to phishing scams or other unsafe pages.
<a href="https://www.example.com" target="_blank" rel="noopener">Visit Example.com</a>Noreferrer:
Prevents the linked resource from identifying the current page as the source of its visitors; so attribution tools like GA4 classify these visitors as "Direct Traffic" in reports, rather than "Referral Traffic", and classify the redirected page as a referral source. "Noreferrer" includes the "noopener" attribute by default, even if the tag doesn't explicitly include it.
<a href="https://example.com" rel="noreferrer">External Link</a>Nofollow:
Does not pass link equity. If not configured, all tag links default to dofollow, passing link equity.
<a href="https://www.example.com" rel="nofollow">This is a nofollow link</a>Sponsored:
A type of Nofollow, for sponsored content, usually affiliate links.
<a href="https://www.example.com/product" rel="sponsored">Learn more about this product</a>UGC:
A type of Nofollow, for user-generated content.
<a href="https://example.com" rel="ugc">User-generated content</a>Target
The "target" attribute tells the user's browser where to open the linked resource. If the tag doesn't contain a "target" attribute value, it defaults to "_self", which opens the linked resource in the same frame. The "_blank" attribute will open the link in a new browser tab or window.
<a href="https://www.example.com" target="_blank">Visit Example.com</a>| rel Attribute Value | Link Equity Passed | Traffic Attribution | Security | Use Cases |
|---|---|---|---|---|
| Default (dofollow) | ✅ Passed | Normal Attribution | Average | Internal links, trusted external links |
| nofollow | ❌ Not Passed | Normal Attribution | Average | Untrusted external links, paid links |
| noopener | ✅ Passed | Normal Attribution | ✅ High | Links opened in new windows |
| noreferrer | ✅ Passed | ❌ Direct Traffic | ✅ High | Privacy protection scenarios |
Main Uses of <a> Tag
- Link to other web pages: Allows users to navigate from the current page to another page, enabling users to read related content and increase dwell time
- Pass link equity: The main SEO purpose, distinguishing it from other link redirect methods
- Link to different parts of the same page: Create table of contents or anchors in long pages, allowing users to click links to jump to specific positions on the page, also called "anchor links" or "jump links"
- Link to other resources: Can link to files (such as PDFs), images, or other resources
- Create placeholder links: Can serve as placeholders for virtual hyperlinks when there's no actual target
Best SEO Practices
- Use <a> tags for all SEO/growth-related pages on the website (user interaction backend doesn't matter)
- <a> tags are crawlable
- Use descriptive anchor text that is concise and specific (don't use "click here"); you can refer to the links on my website, which are all carefully optimized
- Don't use Nofollow for Internal Links; use Nofollow for External Links as a safety measure
Summary
The <a> tag is the infrastructure of website SEO, directly affecting search engine crawling efficiency and link equity distribution.
Key Points:
- Avoid JS redirects, use standard HTML <a> tags to ensure crawler recognition
- Properly configure rel attributes: keep dofollow for internal links, choose nofollow for external links based on trust level
- Optimize anchor text: descriptive, keyword-rich, moderate length (8-12 words)
- Prioritize user experience: appropriately use target="_blank" and rel="noopener"
Implementation Recommendations:
- Immediately audit existing website link implementation methods
- Use Google Search Console to monitor link crawling status
- Regularly check internal link structure and anchor text optimization level
Following these practices will significantly improve your website's search engine friendliness and user experience.
References
- HTML Anchor Element: A Simple Guide for Beginners – Semrush
- Google's Link Best Practices – Google Official Documentation