JavaScript SEO office hours May 6th, 2020

TL;DR

Discussion on JavaScript SEO practices and tools, including Lighthouse and server-side rendering.

Transcript

MARTIN SPLITT: All right. Hello and welcome to this week's JavaScript SEO office hours. My name is Martin Splitt. I work for the search relations team in Google, or at Google in Zurich, right now working from home office, as you can probably tell. And it is my pleasure to answer your JavaScript SEO-related questions. With me today are a few people ... Read More

Key Insights

• Lighthouse and Page Speed Insights are tools for developers and SEOs to assess website speed and user experience, but they are not directly linked to search ranking factors.
• Web Vitals, including Largest Contentful Paint and Cumulative Layout Shift, are metrics introduced to approximate user experience in terms of loading speed.
• Dynamic rendering using JavaScript for canonical tags is acceptable if the tags are correctly inserted in the head section of the HTML.
• Google Tag Manager is a viable solution for implementing tags when developer resources are limited, but it can impact speed due to additional JavaScript.
• Server-side rendering is recommended for better performance and compatibility with bots that do not execute JavaScript, but it's not necessary for Google Bot.
• Crawl budget affects the number of requests Google Bot can make, including those for JavaScript files, but it is not specific to JavaScript sites.
• Service Workers serving WebP images can impact how Google Bot sees images, as Google Bot does not run Service Workers.
• Testing tools like Mobile Friendly Test and Google Search Console are essential for verifying how Google Bot sees and renders JavaScript content.

Questions & Answers

Q: Will Lighthouse become a ranking factor for website issues?

Lighthouse is a tool for evaluating website speed and user experience, not a direct ranking factor. It helps developers and SEOs understand how fast a website feels to users by modeling performance with proxy metrics. While page speed is already a ranking factor, Lighthouse itself is not directly linked to search rankings.

Q: Is it acceptable to serve canonical tags via JavaScript?

Yes, it is acceptable to serve canonical tags via JavaScript as long as they are correctly inserted in the head section of the rendered HTML. It is important to use testing tools to ensure that the canonical tags appear as expected in the rendered HTML.

Q: What are the best practices for implementing tags using Google Tag Manager?

Google Tag Manager is useful when developer resources are limited, but it can impact speed due to additional JavaScript. If possible, implement tags directly in the page or with your own JavaScript. If you must use Google Tag Manager, ensure it does not introduce unnecessary dependencies or slow down the site.

Q: Is server-side rendering necessary for JavaScript sites?

Server-side rendering is not necessary for Google Bot, as it can execute JavaScript. However, server-side rendering can improve performance and is beneficial for compatibility with bots that do not execute JavaScript, such as social media bots. It is recommended for better user experience and faster loading times.

Q: How does crawl budget affect JavaScript sites?

Crawl budget determines how many requests Google Bot can make, including those for JavaScript files. While it affects all sites, not just JavaScript sites, it is important to optimize JavaScript files to ensure efficient crawling. Bundling and code splitting can help manage crawl budget effectively.

Q: Can Service Workers serving WebP images impact SEO?

Service Workers can serve WebP images to browsers that support them, but Google Bot does not run Service Workers. As a result, Google Bot may not see the WebP images, which could impact how images are indexed. It is important to ensure that image formats are accessible to Google Bot.

Q: How can testing tools help with JavaScript SEO?

Testing tools like Mobile Friendly Test and Google Search Console are essential for verifying how Google Bot renders JavaScript content. They help identify issues with resources loading and ensure that the rendered HTML matches expectations. These tools are crucial for debugging and optimizing JavaScript sites.

Q: What factors should be considered when choosing a JavaScript framework?

Choosing a JavaScript framework depends on project requirements, team preferences, and the desired level of abstraction. Frameworks like Angular, React, and Vue offer different features and ecosystems. Consider factors such as TypeScript support, server-side rendering capabilities, and community resources when selecting a framework.

Summary & Key Takeaways

• The session covers important aspects of JavaScript SEO, including the use of Lighthouse and Page Speed Insights for evaluating website speed. It emphasizes the importance of user experience metrics like Web Vitals for assessing loading speed.

• Dynamic rendering with JavaScript for canonical tags is considered acceptable if the tags are correctly placed in the HTML head. The session also discusses the use of Google Tag Manager and its potential impact on website speed.

• Server-side rendering is recommended for better performance and compatibility with non-JavaScript bots. The session highlights the importance of using testing tools to verify how Google Bot renders JavaScript content.