The slides from Calum’s presentation about progressive web apps. There are links throughout to some handy resources.
Friday, July 14th, 2017
Thursday, December 8th, 2016
Jason talks through the service worker strategy for his company website.
Sunday, December 4th, 2016
Henrik points to some crucial information that slipped under the radar at the Chrome Dev Summit—the Android OS is going to treat progressive web apps much more like regular native apps. This is kind of a big deal.
It’s a good time to go all in on the web. I can’t wait to see what the next few years bring. Personally, I feel like the web is well poised to replace the majority of apps we now get from app stores.
Monday, September 19th, 2016
A nice introduction to progressive web apps. There’s a little bit of confusion about permissions—whether a site has been added to the home screen or not has no effect on the permissions granted to it (for things like push notifications)—but the wrap-up nails the advantages of using the web:
No more waiting to download an app, no more prompts for updating an app. From a developer perspective, it means we will be able to iterate a lot quicker. We don’t need to wait for app store approvals anymore, and we can deploy at our own leisure.
Another advantage that a progressive web app has over a native mobile app is that it is linkable, hence it is easier to share and, probably even more importantly, can be indexed by search engines. This makes discoverability of the app a lot better.
Wednesday, June 22nd, 2016
Tuesday, June 7th, 2016
Smart thinking from Alex on how browsers could better indicate that a website is a progressive web app (and would therefore benefit from being added to the home screen). Ambient badging, he calls it.
Wouldn’t it be great if there were a button in the URL bar that appeared whenever you landed on a PWA that you could always tap to save it to your homescreen? A button that showed up in the top-level UI only when on a PWA? Something that didn’t require digging through menus and guessing about “is this thing going to work well when launched from the homescreen?”
Monday, May 30th, 2016
Regression toward being mean
I highly recommend Remy’s State Of The Gap post—it’s ace. He summarises it like this:
I strongly believe in the concepts behind progressive web apps and even though native hacks (Flash, PhoneGap, etc) will always be ahead, the web, always gets there. Now, today, is an incredibly exciting time to be build on the web.
I agree completely. That might sound odd after I wrote about Regressive Web Apps, but it’s precisely because I’m so excited by the technologies behind progressive web apps that I think it’s vital that we do them justice. As Remy says:
Without HTTPS and without service workers, you can’t add to homescreen. This is an intentionally high bar of entry with damn good reasons.
When the user installs a PWA, it has to work. It’s our job as web developers to provide the most excellent experience for our users.
It has to work.
That’s why I don’t agree with Dion’s metrics for what makes a progressive web app:
If you deliver an experience that only works on mobile is that a PWA? Yes.
I think it’s important to keep quality control high. Being responsive is literally the first item in the list of qualities that help define what a progressive web app is. That’s why I wrote about “regressive” web apps: sites that are supposed to showcase what we can do but instead take a step backwards into the bad old days of separate sites for separate device classes: washingtonpost.com/pwa, m.flipkart.com, lite.5milesapp.com, app.babe.co.id, m.aliexpress.com.
A lot of people on Twitter misinterpreted my post as saying “the current crop of progressive web apps are missing the mark, therefore progressive web apps suck”. What I was hoping to get across was “the current crop of progressive web apps are missing the mark, so let’s make better ones!”
Now, I totally understand that many of these examples are a first stab, a way of testing the waters. I absolutely want to encourage these first attempts and push them further. But I don’t think that waiving the qualifications for progressive web apps helps achieves that. As much as I want to acknowledge the hard work that people have done to create those device-specific examples, I don’t think we should settle for anything less than high-quality progressive web apps that are as much about the web as they are about apps.
Simply put, in this instance, I don’t think good intentions are enough.
Which brings me to the second part of Regressive Web Apps, the bit about Chrome refusing to show the “add to home screen” prompt for sites that want to have their URL still visible when launched from the home screen.
if you think the URL is going to get killed on my watch then you aren’t paying any attention whatsoever.
so, your choices are to think that I have a secret plan to kill URLs, or conclude I’m still Team Web.
I’m galled that anyone, particularly you @adactio, would think the former…but contrarianism uber alles?
I am very, very sorry that I upset Alex like this.
But I stand by my criticism of the actions of the Chrome team. Because good intentions are not enough.
I know that Alex is huge fan of URLs, and of the web. Heck, just about everybody I know that works on Chrome in some capacity are working for the web first and foremost: Alex, Jake, various and sundry Pauls. But that doesn’t mean I’m going to stay quiet when I see the Chrome team do something I think is bad for the web. If anything, it’s precisely because I hold them to a high standard that I’m going to sound the alarm when I see what I consider to be missteps.
I think that good people can make bad decisions with the best of intentions. Usually it involves long-term thinking—something I think is very important. “The ends justify the means” is a way of thinking that can create a lot of immediate pain, even if it means a better future overall. Balancing those concerns is front and centre of the Chromium project:
As browser implementers, we find that there’s often tension between (a) moving the web forward and (b) preserving compatibility. On one hand, the web platform API surface must evolve to stay relevant. On the other hand, the web’s primary strength is its reach, which is largely a function of interoperability.
For example, when Alex talks of the Web Component era as though it were an inevitability, I get nervous. Not for myself, but for the millions of Opera Mini users out there. How do we get to a better future without leaving anyone behind? Or do we sacrifice those people for the greater good? Do the needs of the many outweigh the needs of the few? Do the ends justify the means?
I hope not. I hope we can find ways to have our accessible cake and eat it too. But it will be really, really hard.
Returning to progressive web apps, I was genuinely shocked and appalled at the way that the Chrome team altered the criteria for the “add to home screen” prompt to discourage exposing URLs. I was also surprised at how badly the change was communicated—it was buried in a bug report that five people contributed to before pushing the change. I only found out about it through a conversation with Paul Kinlan. Paul encouraged me to give feedback, and that’s what I did on my website, just like Stuart did on his.
Of course the Chrome team are working on ways of exposing URLs within progressive web apps that are launched in from the home screen. Opera are working on it too. But it’s a really tricky problem to solve. It’s not enough to say “we’ll figure it out”. It’s not enough to say “trust us.”
I do trust the people I know working on Chrome. I also trust the people I know at Mozilla, Opera and Microsoft. That doesn’t mean I’m going to let their actions go unquestioned. Good intentions are not enough.
As Alex readily acknowledges, the harder problem (figuring out how to expose URLs) should have been solved first—then the change to the “add to home screen” metrics would be uncontentious. Putting the cart before the horse, discouraging
display:browser now, while saying “trust us, we’ll figure it out”, is another example of saying the ends justify the means.
But the stakes are too high here to let this pass. Good intentions are not enough. Knowing that the people working on Chrome (or Firefox, or Opera, or Edge) are good people is not reason enough to passively accept every decision they make.
Alex called me out for not getting in touch with him directly about the Chrome team’s future plans with URLs, but again, that kind of rough consensus to do something is trumped by running code. Also, I did talk to Chrome people—this all came out of a discussion with Paul Kinlan. I don’t know who’s who in the company’s political hierarchy and I don’t think I should need an org chart to give feedback to Google (or Mozilla, or Opera, or Microsoft).
You’ll notice that I didn’t include Apple there. I don’t hold them to the same high standard. As it turns out, I know some very good people at Apple working on WebKit and Safari. As individuals, they care about the web. But as a company, Apple has shown indifference towards web developers. As Remy put it:
Even getting the hint of interest from Apple is a process of dumpster-diving the mailing lists scanning for the smallest hint of interest.
With that in mind, I completely understand Alex’s frustration with my post on “regressive” web apps. Although I intended it as a push towards making better progressive web apps, I can see how it could be taken as confirmation by those who think that progressive web apps aren’t worth investing in. Apple, for example. As it is, they’ll have to be carried kicking and screaming into adding support for Service Workers, manifest files, and other building blocks. From the reaction to my post from at least one WebKit developer on Twitter, not only did I fail to get across just how important the technologies behind progressive web apps are, I may have done more harm than good, giving ammunition to sceptics.
Still, I hope that most people took my words in the right spirit, like Addy:
We should push them to do much better. I’ll file bugs. Per @adactio post, can’t forget the ‘Progressive’ part of PWAs
Seeing that reaction makes me feel good …but seeing Alex’s reaction makes me feel bad. Very bad. I’m genuinely sorry that I made Alex feel that way. It wasn’t my intention but, well …good intentions are not enough.
I’ve been looking back at what I wrote, trying to see it through Alex’s eyes, looking for the parts that could be taken as a personal attack:
Chrome developers have decided that displaying URLs is not “best practice” … To declare that all users of all websites will be confused by seeing a URL is so presumptuous and arrogant that it beggars belief. … Withholding the “add to home screen” prompt like that has a whiff of blackmail about it. … This isn’t the first time that Chrome developers have made a move against the address bar. It’s starting to grind me down.
Some pretty strong words there. I stand by them, but the tone is definitely strident.
When we criticise something—a piece of software, a book, a website, a film, a piece of music—it’s all too easy to forget that there are real people behind it. But that isn’t the case here. I know that there are real people working on Chrome, because I know quite a few of those people. I also know that their intentions are good. That’s not a reason for me to remain silent—that’s a reason for me to speak up.
If I had known that my post was going to upset Alex, would I have still written it? That’s a tough one. On the one hand, this is a topic I care passionately about. I think it’s vital that we don’t compromise on the very things that make the web great. On the other hand, who knows if what I wrote will make the slightest bit of difference? In which case, I got the catharsis of getting it off my chest but at the price of upsetting somebody I respect. That price feels too high.
I love the fact that I can publish whatever I want on my own website. It can be a place for me to be enthusiastic about things that excite me, and a place for me to rant about things that upset me. I estimate that the enthusiastic stuff outnumbers the ranty stuff by about ten to one, but negativity casts a disproportionately large shadow.
I need to get better at tempering my words. Not that I’m going to stop criticising bad decisions when I see them, but I need to make my intentions clearer …because just having good intentions is not enough. Throughout this post, I’ve mentioned repeatedly how much I respect the people I know working on the Chrome team. I should have said that in my original post.
Monday, May 23rd, 2016
Issue 596729 - chromium - Do not show the app banner unless the Manifest has a display set to standalone or fullscreen - Monorail
I am shocked and disgusted by this arbitrary decision by the Chrome team. If your Progressive Web App doesn’t set its manifest to obscure its URL, you get punished by missing out on the add to home screen prompt.
Wednesday, April 6th, 2016
While many challenges remain, the good news is … it’s progressive. Developers can already see the benefits by sprinkling in these technologies to their existing websites and proceed to build on them as browsers and operating systems increase support.
Monday, March 21st, 2016
Friday, March 18th, 2016
Remy sums up the psychological end goal of progressive apps (HTTPS + Service Worker + manifest JSON file) prompting an add to home screen action:
This high bar of entry will create a new mental model for our users.
If I add this app to my home screen, it will work when I open it.
It’s a shame that this charge to turbo-boast the perception of the web on mobile is a bit one-sided: I would love to see Apple follow Google’s lead here. But if Android succeed in their goal, then I think iOS will have to follow suit just to compete.
Friday, November 27th, 2015
Bruce gives a great run-down of what’s involved in creating one of those new-fangled progressive apps that everyone at Google and Opera (and soon, Mozilla) are talking about: a secure connection, a service worker, and a manifest file.
Crucially, in browsers that don’t support it, you have a normal website. It’s perfect progressive enhancement.
Funnily enough, this here website—adactio.com—is technically a progressive app now.
At their simplest, Progressive Web Apps are application-like things hosted on your web server. If you’re as old as me, you might call them “web sites”
Wednesday, November 18th, 2015
Sunday, November 15th, 2015
That “Add To Home Screen” dialogue is not something that Remy explicitly requested (though, of course, you can—and should—choose to add adactio.com to your home screen). That prompt appears in Chrome on Android as the result of a fairly simple algorithm based on a few factors:
- The website is served over HTTPS. My site is.
- The website has a manifest file. Here’s my JSON manifest file.
- The website has a Service Worker. Here’s my site’s Service Worker script (although a little birdie told me that the Service Worker script can be as basic as a blank file).
- The user visits the website a few times over the course of a few days.
I think that’s a reasonable set of circumstances. I particularly like that there is no way of forcing the prompt to appear.
There are some carrots in there: Want to have the user prompted to add your site to their home screen? Well, then you need to be serving on a secure connection, and you’d better get on board that Service Worker train.
Speaking of which, after I published a walkthrough of my first Service Worker, I got an email bemoaning the lack of browser support:
I was very much interested myself in this topic, until I checked on the “Can I use…” site the availability of this technology. In one word “limited”. Neither Safari nor IOS Safari support it, at least now, so I cannot use it for implementing mobile applications.
I don’t think this is the right way to think about Service Workers. You don’t build your site on top of a Service Worker—you add a Service Worker on top of your existing site. It has been explicitly designed that way: you can’t make it the bedrock of your site’s functionality; you can only add it as an enhancement.
I think that’s really, really smart. It means that you can start implementing Service Workers today and as more and more browsers add support, your site will appear to get better and better. My site worked fine for fifteen years before I added a Service Worker, and on the day I added that Service Worker, it had no ill effect on non-supporting browsers.
Oh, and according to the Webkit five year plan, Service Worker support is on its way. This doesn’t surprise me. I can’t imagine that Apple would let Google upstage them for too long with that nice “add to home screen” flow.
Alas, Mobile Safari’s glacial update cycle means that the earliest we’ll see improvements like Service Workers will probably be September or October of next year. In the age of evergreen browsers, Apple’s feast-or-famine approach to releasing updates is practically indistinguishable from stagnation.
Still, slowly but surely, game-changing technologies are landing in browsers. At the same time, the long-term problems with betting on native apps are starting to become clearer. Native apps are still ahead of what can be accomplished on the web, but it was ever thus:
The web will always be lagging behind some other technology. I’m okay with that. If anything, I see these other technologies as the research and development arm of the web. CD-ROMs, Flash, and now native apps show us what authors want to be able to do on the web. Slowly but surely, those abilities start becoming available in web browsers.
The pace of this standardisation can seem infuriatingly slow. Sometimes it is too slow. But it’s important that we get it right—the web should hold itself to a higher standard. And so the web plays the tortoise while other technologies race ahead as the hare.
It’s interesting to see how the web could take the desirable features of native—offline support, smooth animations, an icon on the home screen—without sacrificing the strengths of the web—linking, responsiveness, the lack of App Store gatekeepers. That kind of future is what Alex is calling progressive apps:
Critically, these apps can deliver an even better user experience than traditional web apps. Because it’s also possible to build this performance in as progressive enhancement, the tangible improvements make it worth building this way regardless of “appy” intent.
What excites me is the prospect of building services that work just fine on low-powered devices with basic browsers, but that also take advantage of all the great possibilities offered by the latest browsers running on the newest devices. Backwards compatible and future friendly.
And if that sounds like a naïve hope, then I humbly suggest that Service Workers are a textbook example of exactly that approach.
Friday, December 19th, 2014
This page does a great job of explaining Mozilla’s thinking behind “pinned apps”—an idea that would be great for the whole web, not just Firefox users.