Vue.js is a popular JavaScript framework that allows developers to build single-page applications (SPA). However, as with any web application, it's important to consider the SEO implications of your site. In this article, we will discuss some common SEO issues and how to fix them when using Vue.js SPA.

1. Meta Descriptions: Without a meta description tag on a page, search engines won't know what the content of the page is about. The meta description should be less than 155 characters long and give users an idea of the main topic being discussed. In Vue.js, you can set the meta description using the <meta> tags in your HTML file or within your component using a library like vue-meta.

2. Title Tags: The title tag is what search engines use to display your site in the search results page (SERP). It's important to make sure that the title tag is concise, descriptive and contains the main keywords being used on the page. In Vue.js, you can set the title tag using the <title> tags in your HTML file or within your component using a library like vue-meta.

3. Keyword Density: Search engines consider keyword density to be one of the most important factors for ranking in SERPs. The more times a keyword appears on a page, the more likely it is that search engines will rank it higher. In Vue.js, you can use libraries like vue-keywords or vue-seo-tags to help manage your keywords density.

4. Content Optimization: Without proper content optimization, search engines won't be able to understand the meaning behind a page and won't know how to rank it. In Vue.js, you can use libraries like vue-markdown or vue-readability to optimize your content for SEO.

5. Robots.txt: The robots.txt file is used by search engines to determine which pages they should crawl and which they shouldn't. It's important to make sure that the rules in your robots.txt file are clear and specific enough to avoid overwhelming search engines with unnecessary content.

6. Schema Markup: Schema markup is a way for search engines to understand the structure of your website and display rich snippets in SERPs. In Vue.js, you can use libraries like vue-schemaorg or vue-structured-data to add schema markup to your site.

By following these SEO best practices, you can help ensure that your Vue.js SPA is a successful search engine optimization (SEO) strategy.