Progressive Web Apps (PWAs) combine web and mobile technologies to create products that can be installed on any platform. This helps to make applications much more marketable, resulting in more user engagement, while also helping brands achieve better SEO metrics and, eventually, more traffic.

Hence, in this article, we will examine the technical building blocks of PWAs, including service workers and the use of web app manifests to improve SERP rankings. Focusing on practical strategies, the goal of the article is to help software developers boost PWA performance, user experience, and search engine visibility.

What is a Progressive Web App (PWA)

Progressive Web Apps (PWA) are web applications that use modern APIs to provide enhanced functionality, while still being able to work on any platform or device using a single codebase. They effectively combine the accessibility of web apps with the rich functionality and user experience of bespoke, platform-specific applications.

The banking and financial sectors often lead the way in terms of PWAs. Providing customers with a range of features in a secure environment, such as offering same-day ACH transfers, loan applications, and investment opportunities.

When designing PWAs, developers need to focus on three key pillars:

• Capability - Developers must build PWAs that offer the same capabilities of a platform-specific application to a wide range of platforms and devices, while also ensuring a sufficient level of security.
• Reliability - PWAs must be fast and reliable, overcoming any network constraints, and ensuring maximum usability across all devices. Fast page loading is essential to a successful PWA.
• Installability - PWAs need to be installable from a browser and then must be easily launchable from wherever it is stored. For example, once installed on a Macbook, users should be able to launch the app from the home screen, taskbar, shelf, or dock based on their preference.

Why PWAs in Particular?

While the simplicity, and ultimately, scalability of PWAs are considered their calling cards, developers and end-users, in some cases, have also noticed that they provide:

• Speed. This is perhaps the most underrated benefit of PWAs when compared to traditional websites, which are built on mostly WordPress (43% of them, to be exact) which has over 60,000 plugins that can impact loading speeds and generate errors. Considering many users install 10+ plug-ins, the impact on performance can be significant.
• Cost-effectiveness. PWAs can also be a relatively low-cost solution, with cloud solutions such as the likes of Kubernetes minimizing the need for physical infrastructure. Costs can be reduced by opting for managed service with customizable options provided by Google and Amazon if you want to find an Azure alternative.

Progressive Web Applications - Technical Building Blocks

Progressive Web Applications consist of various features or building blocks that ensure they adhere to the three pillars outlined in the previous section. Now, let’s get into the nitty gritty and take a look at the four pillars of every functional PWA.

Service Workers

A fundamental building block of progressive web applications is service workers. Service workers are scripts of code that are run by browsers in the background, completely separate from the web page. This allows features to be run that don’t need to be launched by the web page or require any user interaction.

Over the years, developers have experienced issues relating to a loss of connectivity. This has led to the development of a range of technologies to help solve the problem. However, a distinct lack of control remained in terms of asset caching and custom network requests.

Service workers are the solution to these problems as they allow developers to create apps that use cached assets by default, even when the user is offline. More data is provided when the connection is reestablished. This is often referred to as an offline-first approach, providing some functionality even if there is no internet connection.

Manifest

A web app manifest is a basic JSON (JavaScript Object Notation) file that instructs the browser on how a PWA should behave once it has been installed on a user’s device. For example, a manifest could instruct Google Chrome to prompt users to add the app to their home screen. At its simplest level, a PWA manifest will at least inform the browser of the app’s name and display icon.

Push Notifications

Push notifications make it provide app users with important information to improve things like app security and user experience. Once the user has consented, these notifications can prompt them to install the latest updates or to inform them about relevant content that they may find interesting.

Creating a push API or even a dedicated notification API makes it possible to engage with users after they have installed a PWA, ensuring they are using the latest version and are using the app to its full potential.

Background Sync

Background sync is a web API that makes it possible to defer actions until the user has a stable network connection. This can be especially useful to ensure messages that are typed offline are eventually sent to the intended recipient - i.e. WhatsApp.

Another use would be saving content (such as a spreadsheet) to a relevant location when a connection has been reestablished, allowing the user to work offline.

Developer Tips to Boost the SEO and Performance of PWAs

Online businesses are under pressure to provide the best possible experience to their users while achieving high search visibility to attract new users and grow as a business. Progressive web apps (PWAs) are the perfect solution.

The challenge for developers is balancing both of these requirements to create effective PWAs, ones that meet the user’s needs while being highly optimized to perform well in search engine page results (SERPs).

With that in mind, here are a few tips and best practices for creating powerful PWAs that get results.

Create Custom URLs

An often overlooked aspect of PWAs is having credible URLs that can dictate a person’s decision on whether to click on a link or not. URLs should be concise, and include the brand name, and relevant keywords. This is essential for boosting SERP performance.

Optimize Content

A PWA can be rich in features and provide a great user experience, but it can still fail to achieve high search rankings if the content is poor. Like a traditional website, PWAs must deliver relevant, useful, and informative content that engages the user.

Likewise, PWAs that contain lots of duplicate content, spelling mistakes, grammatical errors, and irrelevant content are likely to be penalized by search engine algorithms - regardless of a great design and architecture.

Implement the Relevant Security

All PWAs must enable HTTPS, a secure transfer protocol that uses encryption to provide a secure connection over a network. This is a standard requirement for search engines such as Google and is a ranking factor.

Use Analysis Tools

A PWA’s SEO score is made of a range of elements, including usability and the amount of technical errors present. To assess performance, you should use a range of SEO analysis tools to gain a comprehensive insight into any issues that might be impacting the success of the application.

JavaScript errors are a common problem that impact SEO performance and need to be identified and fixed. At the same time, developers must also be wary of any problems that might arise from integration with novelties such as cloud automation, AI-enhanced development, and the handling of more complex JS libraries, mainly Tensorflow.js and Brain.js.

As for the most popular tools, you can utilize:

• Google Search Console
• Google Analytics
• SEMRush
• AhREfs
• Google Lighthouse PWA Analysis Tool
• Google PageSpeed Insights

Check the Crawlability of the PWA

To ensure your PWA can be crawled by search engines and that all relevant pages are indexed, a sitemap and robots.txt need to be submitted. The sitemap is a list of web pages in a hierarchical structure that makes it easy for crawlbots to navigate a PWA or website. Meanwhile, the robots.txt provides instructions to search engines regarding which pages they can access.

In terms of Google, this can be done by logging into the Google Search Console and following the links to submit your sitemap manually and test your robots.txt is working as it should.

Conclusion

PWAs have the potential to help to take online businesses to the next level, providing a range of features and functionality that merge web applications with bespoke, single-platform applications. These features allow users to perform actions while offline, offer lightning-quick loading speeds, advanced security, and much more.

To ensure PWAs achieve high search engine rankings and meet the requirements of the user, developers need to follow simple best practices and ensure all aspects of the app are considered in detail. After all, we all know how calamitous an improper execution can be.