Tags: apps

I received this email recently:

Subject: multi-page web apps

Hi Jeremy,

lately I’ve been following you through videos and texts and I’m curious as to why you advocate the use of multi-page web apps and not single-page ones.

Perhaps you can refer me to some sources where your position and reasoning is evident?

Here’s the response I sent…

Hi,

You can find a lot of my reasoning laid out in this (short and free) online book I wrote called Resilient Web Design:

https://resilientwebdesign.com/

The short answer to your question is this: user experience.

The slightly longer answer…

For most use cases, a website (or multi-page app if you prefer) is going to provide the most robust experience for the most number of users. That’s because a user’s web browser takes care of most of the heavy lifting.

Navigating from one page to another? That’s taken care of with links.

Gathering information from a user to process on a server? That’s taken care of with forms.

This frees me up to concentrate on the content and the design without having to reinvent the wheels of links and form fields.

These (let’s call them) multi-page apps are stateless, and for most use cases that’s absolutely fine.

There are some cases where you’d want a state to persist across pages. Let’s say you’re playing a song, or a podcast episode. Ideally you’d want that player to continue seamlessly playing even as the user navigates around the site. In that situation, a single-page app would be a suitable architecture.

But that architecture comes at a cost. Now you’ve got stop the browser doing what it would normally do with links and forms. It’s up to you to recreate that functionality. And you can’t do it with HTML, a robust fault-tolerant declarative language. You need to reimplement all that functionality in JavaScript, a less tolerant, more brittle language.

Then you’ve got to ship all that code to the user before they can use your site. It might be JavaScript code you’ve written yourself or it might be a third-party library designed for building single-page apps. Either way, the user pays a download tax (and a parsing tax, and an execution tax). Whereas with links and forms, all of that functionality is pre-bundled into the user’s web browser.

So that’s my reasoning. At least nine times out of ten, a multi-page approach is leaner, more robust, and simpler.

Like I said, there are times when a single-page approach makes sense—it all comes down to whether state needs to be constantly preserved. But these use cases are the exceptions, not the rule.

That’s why I find the framing of your question a little concerning. It should be inverted. The default approach should be to assume a multi-page approach (which is the way the web works by default). Deciding to take a JavaScript-driven single-page approach should be the exception.

It’s kind of like when people ask, “Why don’t you have children?” Surely the decision to have a child should require deliberation and commitment, rather than the other way around.

When it comes to front-end development, I’m worried that we’ve reached a state where the more complex over-engineered approach is viewed as the default.

I may be committing a fundamental attribution error here, but I think that we’ve reached this point not because of any consideration for users, but rather because of how it makes us developers feel. Perhaps building an old-fashioned website that uses HTML for navigations feels too easy, like it’s beneath us. But building an “app” that requires JavaScript just to render text on a screen feels like real programming.

I hope I’m wrong. I hope that other developers will start to consider user experience first and foremost when making architectural decisions.

Anyway. That’s my answer. User experience.

Cheers,

Jeremy

The most cartoonish misrepresentation of progressive enhancement is that it means making everything work without JavaScript.

No. Progressive enhancement means making sure your core functionality works without JavaScript.

In my book Resilient Web Design, I quoted Wilto:

Lots of cool features on the Boston Globe don’t work when JS breaks; “reading the news” is not one of them.

That’s an example where the core functionality is readily identifiable. It’s a newspaper. The core functionality is reading the news.

It isn’t always so straightforward though. A lot of services that self-identify as “apps” will claim that even their core functionality requires JavaScript.

Surely I don’t expect Gmail or Google Docs to provide core functionality without JavaScript?

In those particular cases, I actually do. I believe that a textarea in a form would do the job nicely. But I get it. That might take a lot of re-engineering.

So how about this compromise…

Your app should work in a read-only mode without JavaScript.

Without JavaScript I should still be able to read my email in Gmail, even if you don’t let me compose, reply, or organise my messages.

Without JavaScript I should still be able to view a document in Google Docs, even if you don’t let me comment or edit the document.

Even with something as interactive as Figma or Photoshop, I think I should still be able to view a design file without JavaScript.

Making this distinction between read-only mode and read/write mode could be very useful, especially at the start of a project.

Begin by creating the read-only mode that doesn’t require JavaScript. That alone will make for a solid foundation to build upon. Now you’ve built a fallback for any unexpected failures.

Now start adding the read/write functionally. You’re enhancing what’s already there. Progressively.

Heck, you might even find some opportunities to provide some read/write functionality that doesn’t require JavaScript. But if JavaScript is needed, that’s absolutely fine.

So if you’re about to build a web app and you’re pretty sure it requires JavaScript, why not pause and consider whether you can provide a read-only version.

Push notifications are finally arriving on iOS—hallelujah! Like I said last year, this is my number one wish for the iPhone, though not because I personally ever plan to use the feature:

When I’m evangelising the benefits of building on the open web instead of making separate iOS and Android apps, I inevitably get asked about notifications. As long as mobile Safari doesn’t support them—even though desktop Safari does—I’m somewhat stumped. There’s no polyfill for this feature other than building an entire native app, which is a bit extreme as polyfills go.

With push notifications in mobile Safari, the arguments for making proprietary apps get weaker. That’s good.

The announcement post is a bit weird though. It never uses the phrase “progressive web apps”, even though clearly the entire article is all about progressive web apps. I don’t know if this down to Not-Invented-Here syndrome by the Apple/Webkit team, or because of genuine legal concerns around using the phrase.

Instead, there are repeated references to “Home Screen apps”. This distinction makes some sense though. In order to use web push on iOS, your website needs to be added to the home screen.

I think that would be fair enough, if it weren’t for the fact that adding a website to the home screen remains such a hidden feature that even power users would be forgiven for not knowing about it. I described the steps here:

1. Tap the “share” icon. It’s not labelled “share.” It’s a square with an arrow coming out of the top of it.
2. A drawer pops up. The option to “add to home screen” is nowhere to be seen. You have to pull the drawer up further to see the hidden options.
3. Now you must find “add to home screen” in the list

• Copy
• Add to Reading List
• Add Bookmark
• Add to Favourites
• Find on Page
• Add to Home Screen
• Markup
• Print

As long as this remains the case, we can expect usage of web push on iOS to be vanishingly low. Hardly anyone is going to add a website to their home screen when their web browser makes it so hard.

If you’d like to people to install your progressive web app, you’ll almost certainly need to prompt people to do so. Here’s the page I made on thesession.org with instructions on how to add to home screen. I link to it from the home page of the site.

I wish that pages like that weren’t necessary. It’s not the best user experience. But as long as mobile Safari continues to bury the home screen option, we don’t have much choice but to tackle this ourselves.

I was chatting with my new colleague Alex yesterday about a link she had shared in Slack. It was the Nielsen Norman Group’s annual State of Mobile User Experience report.

There’s nothing too surprising in there, other than the mention of Apple’s app clips and Google’s instant apps.

Remember those?

Me neither.

Perhaps I lead a sheltered existence, but as an iPhone user, I don’t think I’ve come across a single app clip in the wild.

I remember when they were announced. I was quite worried about them.

See, the one thing that the web can (theoretically) offer that native can’t is instant access to a resource. Go to this URL—that’s it. Whereas for a native app, the flow is: go to this app store, find the app, download the app.

(I say that the benefit is theoretical because the website found at the URL should download quickly—the reality is that the bloat of “modern” web development imperils that advantage.)

App clips—and instant apps—looked like a way to route around the convoluted install process of native apps. That’s why I was nervous when they were announced. They sounded like a threat to the web.

In reality, the potential was never fulfilled (if my own experience is anything to go by). I wonder why people didn’t jump on app clips and instant apps?

Perhaps it’s because what they promise isn’t desirable from a business perspective: “here’s a way for users to accomplish their tasks without downloading your app.” Even though app clips can in theory be a stepping stone to installing the full app, from a user’s perspective, their appeal is the exact opposite.

Or maybe they’re just too confusing to understand. I think there’s an another technology that suffers from the same problem: progressive web apps.

Hear me out. Progressive web apps are—if done well—absolutely amazing. You get all of the benefits of native apps in terms of UX—they even work offline!—but you retain the web’s frictionless access model: go to a URL; that’s it.

So what are they? Are they websites? Yes, sorta. Are they apps? Yes, sorta.

That’s confusing, right? I can see how app clips and instant apps sound equally confusing: “you can use them straight away, like going to a web page, but they’re not web pages; they’re little bits of apps.”

I’m mostly glad that app clips never took off. But I’m sad that progressive web apps haven’t taken off more. I suspect that their fates are intertwined. Neither suffer from technical limitations. The problem they both face is inertia:

The technologies are the easy bit. Getting people to re-evaluate their opinions about technologies? That’s the hard part.

True of progressive web apps. Equally true of app clips.

But when I was chatting to Alex, she made me look at app clips in a different way. She described a situation where somebody might need to interact with some kind of NFC beacon from their phone. Web NFC isn’t supported in many browsers yet, so you can’t rely on that. But you don’t want to make people download a native app just to have a quick interaction. In theory, an app clip—or instant app—could do the job.

In that situation, app clips aren’t a danger to the web—they’re polyfills for hardware APIs that the web doesn’t yet support!

I love having my perspective shifted like that.

The specific situations that Alex and I were discussing were in the context of museums. Musuems offer such interesting opportunities for the physical and the digital to intersect.

Remember the pen from Cooper Hewitt? Aaron spoke about it at dConstruct 2014—a terrific presentation that’s well worth revisiting and absorbing.

The other dConstruct talk that’s very relevant to this liminal space between the web and native apps is the 2012 talk from Scott Jenson. I always thought the physical web initiative had a lot of promise, but it may have been ahead of its time.

I loved the thinking behind the physical web beacons. They were deliberately dumb, much like the internet itself. All they did was broadcast a URL. That’s it. All the smarts were to be found at the URL itself. That meant a service could get smarter over time. It’s a lot easier to update a website than swap out a piece of hardware.

But any kind of technology that uses Bluetooth, NFC, or other wireless technology has to get over the discovery problem. They’re invisible technologies, so by default, people don’t know they’re even there. But if you make them too discoverable— intrusively announcing themselves like one of the commercials in Minority Report—then they’re indistinguishable from spam. There’s a sweet spot of discoverability right in the middle that’s hard to get right.

Over the past couple of years—accelerated by the physical distancing necessitated by The Situation—QR codes stepped up to the plate.

They still suffer from some discoverability issues. They’re not human-readable, so you can’t be entirely sure that the URL you’re going to go to isn’t going to be a Rick Astley video. But they are visible, which gives them an advantage over hidden wireless technologies.

They’re cheaper too. Printing a QR code sticker costs less than getting a plastic beacon shipped from China.

QR codes turned out to be just good enough to bridge the gap between the physical and digital for those one-off interactions like dining outdoors during a pandemic:

I can see why they chose the web over a native app. Online ordering is the only way to place your order at this place. Telling people “You have to go to this website” …that seems reasonable. But telling people “You have to download this app” …that’s too much friction.

Ironically, the nail in the coffin for app clips and instant apps might’ve been hammered in by Apple and Google when they built QR-code recognition into their camera software.

When I wrote about my hopes and fears for the View Transitions API, a few people latched on to this sentiment:

If the View Transitions API only works for single page apps, it could be the single worst thing to happen to the web in years.

But I also wrote:

If the View Transitions API works across page navigations, it could be the single best thing to happen to the web in years.

I think it’s worth focusing on that.

Part of the problem is that I gave my hopes and fears an equal airing. But they’re not equally likely.

Take the possibility that the View Transitions API only ships for single page apps, but never ships for regular page transitions. The consequences of that would be big—the API would act as an incentive to build single page apps. But the likelihood of that happening is small. In fact, according to Jake, there’s already an implemention for page transitions in the works at Chrome.

Now what if the View Transitions API ships for pages? The consequences would be equally big—the API would act as an incentive to ditch single page apps and build in a more performant, resilient way. Best of all, the chances of that happening are very large indeed (pretty much a certainty now, given Jake’s update).

So I made a comparison between both of the consequences, which are equally large, but I didn’t make a corresponding comparison of the likelihoods, which are not equally large. Mea culpa!

I should’ve made it clearer that, although the consequences would be really bad if the View Transitions API only supports single page apps, the actual likelihood of that is pretty slim.

That’s probably my negativity bias showing through. (The reason I have a negativity bias is because I am a human. Like, have you ever noticed that if you get feedback on something and 98% of it is positive, you inevitably fixate on the 2%?)

Anyway, the real takeaway here is that if the View Transitions API ships for pages, then the consequences will be really, really good! It would be another nail in the coffin for monolithic JavaScript frameworks slowing down the web. And best of all, the likelihood of this happening is very high!

So let me amend my closing sentences from my previous post:

If the View Transitions API only works for single page apps—which is very unlikely—it could be the single worst thing to happen to the web in years.

If the View Transitions API works across page navigations—which is very, very likely—it could be the single best thing to happen to the web in years.

The glass is half full and it’s only going to get fuller. Time to start planning for a turbo-charged web now.

If you’ve got a website with full page navigations, start thinking about how you’ll be able to apply the View Transitions API as a progressive enhancement to improve the user experience.

If you’ve got a single page app, start thinking about how to ditch a whole bunch of uneccessary dependencies to make a more lightweight foundation of HTML instead of JavaScript, and still get all those slick transitions you get in a single page app!