Tags: navigation

When I was talking about monitoring web performance yesterday, I linked to the CrUX data for The Session.

CrUX is a contraction of Chrome User Experience Report. CrUX just sounds better than CEAR.

It’s data gathered from actual Chrome users worldwide. It can be handy as part of a balanced performance-monitoring diet, but it’s always worth remembering that it only shows a subset of your users; those on Chrome.

The actual CrUX data is imprisoned in some hellish Google interface so some kindly people have put more humane interfaces on it. I like Calibre’s CrUX tool as well as Treo’s.

What’s nice is that you can look at the numbers for any reasonably popular website, not just your own. Lest I get too smug about the performance metrics for The Session, I can compare them to the numbers for WikiPedia or the BBC. Both of those sites are made by people who prioritise speed, and it shows.

If you scroll down to the numbers on navigation types, you’ll see something interesting. Across the board, whether it’s The Session, Wikipedia, or the BBC, the BFcache—back/forward cache—is used around 16% to 17% of the time. This is when users use the back button (or forward button).

Unless you do something to stop them, browsers will make sure that those navigations are super speedy. You might inadvertently be sabotaging the BFcache if you’re sending a Cache-Control: no-store header or if you’re using an unload event handler in JavaScript.

I guess it’s unsurprising the BFcache numbers are relatively consistent across three different websites. People are people, whatever website they’re browsing.

• The Session
• WikiPedia
• The BBC

Where it gets interesting is in the differences. Take a look at pre-rendering. It’s 4% for the BBC and just 0.4% for Wikipedia. But on The Session it’s a whopping 35%!

That’s because I’m using speculation rules. They’re quite straightforward to implement and they pair beautifully with full-page view transitions for a slick, speedy user experience.

It doesn’t look like WikiPedia or the BBC are using speculation rules at all, which kind of surprises me.

Then again, because they’re a hidden technology I can understand why they’d slip through the cracks.

On any web project, I think it’s worth having a checklist of The Invisibles—things that aren’t displayed directly in the browser, but that can make a big difference to the user experience.

Some examples:

• A web application manifest JSON file to help people install your website.
• A service worker, even if it’s just to cache static assets.
• Open Graph meta elements in the head of documents so they “unroll” nicely when the link is shared.
• An appropriate content security policy header.
• A Speculation-Rules header that points to a JSON file.
• An OpenSearch XML file if your site has search functionality.
• An icon, or as us olds call it, a favicon.
• A lang attribute on the body of every page.

If you’ve got a checklist like that in place, you can at least ask “Whose job is this?” All too often, these things are missing because there’s no clarity on whose responsible for them. They’re sorta back-end and sorta front-end.

Who’s Afraid of a Hard Page Load?

Why single-page apps are just not worth it:

Here’s the problem: your team almost certainly doesn’t have what it takes to out-engineer the browser. The browser will continuously improve the experience of plain HTML, at no cost to you, using a rendering engine that is orders of magnitude more efficient than JavaScript.

Meanwhile, the browser marches on, improving the UX of every website that uses basic HTML semantics. For instance: browsers often don’t repaint full pages anymore.

But what if I really want a faster horse? | exotext

Overall, consistency, user control, and actual UX innovation are in decline. Everything is converging on TikTok—which is basically TV with infinite channels. You don’t control anything except the channel switch. It’s like Carcinisation, a form of convergent evolution where unrelated crustaceans all evolve into something vaguely crab-shaped.

Building WebSites With LLMS - Jim Nielsen’s Blog

And by LLMS I mean: (L)ots of (L)ittle ht(M)l page(S).

I really like this approach: using separate pages instead of in-page interactions. I remember Simon talking about how great this works, and that was a few years back, before we had view transitions.

I build separate, small HTML pages for each “interaction” I want, then I let CSS transitions take over and I get something that feels better than its JS counterpart for way less work.

Popover API Sliding Nav

Here’s a nifty demo of popover but it’s not for what we’d traditionally consider a modal dialog.

There’s a new addition to the latest version of Chrome called speculation rules. This already existed before with a different syntax, but the new version makes more sense to me.

Notice that I called this an addition, not a standard. This is not a web standard, though it may become one in the future. Or it may not. It may wither on the vine and disappear (like most things that come from Google).

The gist of it is that you give the browser one or more URLs that the user is likely to navigate to. The browser can then pre-fetch or even pre-render those links, making that navigation really snappy. It’s a replacement for the abandoned link rel="prerender".

Because this is a unilateral feature, I’m not keen on shipping the code to all browsers. The old version of the API required a script element with a type value of “speculationrules”. That doesn’t do any harm to browsers that don’t support it—it’s a progressive enhancement. But unlike other progressive enhancements, this isn’t something that will just start working in those other browsers one day. I mean, it might. But until this API is an actual web standard, there’s no guarantee.

That’s why I was pleased to see that the new version of the API allows you to use an external JSON file with your list of rules.

I say “rules”, but they’re really more like guidelines. The browser will make its own evaluation based on bandwidth, battery life, and other factors. This feature is more like srcset than source: you give the browser some options, but ultimately you can’t force it to do anything.

I’ve implemented this over on The Session. There’s a JSON file called speculationrules.js with the simplest of suggestions:

{
  "prerender": [{
    "where": {
        "href_matches": "/*"
    },
    "eagerness": "moderate"
  }]
}

The eagerness value of “moderate” says that any link can be pre-rendered if the user hovers over it for 200 milliseconds (the nuclear option would be to use a value of “immediate”).

I still need to point to that JSON file from my HTML. Usually this would be done with something like a link element, but for this particular API, I can send a response header instead:

Speculation-Rules: “/speculationrules.json"

I like that. The response header is being sent to every browser, regardless of whether they support speculation rules or not, but at least it’s just a few bytes. Those other browsers will ignore the header—they won’t download the JSON file.

Here’s the PHP I added to send that header:

header('Speculation-Rules: "/speculationrules.json"');

There’s one extra thing I had to do. The JSON file needs to be served with mime-type of “application/speculationrules+json”. Here’s how I set that up in the .conf file for The Session on Apache:

<IfModule mod_headers.c>
  <FilesMatch "speculationrules.json">
    Header set Content-type application/speculationrules+json
   </FilesMatch>
</IfModule>

A bit of a faff, that.

You can see it in action on The Session. Open up Chrome or Edge (same same but different), fire up the dev tools and keep the network tab open while you navigate around the site. Notice how hovering over a link will trigger a new network request. Clicking on that link will get you that page lickety-split.

Mind you, in the case of The Session, the navigations were already really fast—performance is a feature—so it’s hard to guage how much of a practical difference it makes in this case, but it still seems like a no-brainer to me: taking a few minutes to add this to your site is worth doing.

Oh, there’s one more thing to be aware of when you’re implementing speculation rules. You have the option of excluding URLs from being pre-fetched or pre-rendered. You might need to do this if you’ve got links for adding items to shopping carts, or logging the user out. But my advice would instead be: stop using GET requests for those actions!

Most of the examples given for unsafe speculative loading conditions are textbook cases of when not to use links. Links are for navigating. They’re indempotent. For everthing else, we’ve got forms.

Historical Trails

Maggie explores different ways of visualising journeys on the web, including browser histories:

Perhaps web browsing histories should look more like Git commit histories? Perhaps distinct branches could representing different topics and research avenues?

A memex in every web browser!

First Experiments with View Transitions for Multi-page Apps

Some great ideas for view transitionts in here! Also:

If you look at any of the examples on a browser that does not support them, the pages still function just fine. The transitions are an extra that’s layered on top if and when your browser supports them. Another concrete example of progressive enhancement in practice.

I must admit, when Jake told me he was leaving Google, I got very worried about the future of the View Transitions API.

To recap: Chrome shipped support for the API, but only for single page apps. That had me worried:

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

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.

Well, the multi-page version still hasn’t yet shipped in Chrome stable, but it is available in Chrome Canary behind a flag, so it looks like it’s almost here!

Robin took the words out of my mouth:

Anyway, even this cynical jerk is excited about this thing.

Are you the kind of person who flips feature flags on in nightly builds to test new APIs?

Me neither.

But I made an exception for the View Transitions API. So did Dave:

I think the most telling predictor for the success of the multi-page View Transitions API – compared to all other proposals and solutions that have come before it – is that I actually implemented this one. Despite animations being my bread and butter for many years, I couldn’t be arsed to even try any of the previous generation of tools.

Dave’s post is an excellent step-by-step introduction to using view transitions on your website. To recap:

Enable these two flags in Chrome Canary:

chrome://flags#view-transition
chrome://flags#view-transition-on-navigation

Then add this meta element to the head of your website:

<meta name="view-transition" content="same-origin">

You could stop there. If you navigate around your site, you’ll see that the navigations now fade in and out nicely from one page to another.

But the real power comes with transitioning page elements. Basically, you want to say “this element on this page should morph into that element on that page.” And when I say morph, I mean morph. As Dave puts it:

Behind the scenes the browser is rasterizing (read: making an image of) the before and after states of the DOM elements you’re transitioning. The browser figures out the differences between those two snapshots and tweens between them similar to Apple Keynote’s “Magic Morph” feature, the liquid metal T-1000 from Terminator 2: Judgement Day, or the 1980s cartoon series Turbo Teen.

If those references are lost on you, how about the popular kids book series Animorphs?

Some classic examples would be:

• A thumbnail of a video on one page morphs into the full-size video on the next page.
• A headline and snippet of an article on one page morphs into the full article on the next page.

I’ve added view transitions to The Session. Where I’ve got index pages with lists of titles, each title morphs into the heading on the next page.

Again, Dave’s post was really useful here. Each transition needs a unique name, so I used Dave’s trick of naming each transition with the ID of the individual item being linked to.

In the recordings section, for example, there might be a link like this on the index page:

<a href="/recordings/7812" style="view-transition-name: recording-7812">The Banks Of The Moy</a>

Which, if you click on it, takes you to the page with this heading:

<h1><span style="view-transition-name: recording-7812">The Banks Of The Moy</span></h1>

Why the span? Well, like Dave, I noticed some weird tweening happening between block and inline elements. Dave solved the problem with width: fit-content on the block-level element. I just stuck in an extra inline element.

Anyway, the important thing is that the name of the view transition matches: recording-7812.

I also added a view transition to pages that have maps. The position of the map might change from page to page. Now there’s a nice little animation as you move from one page with a map to another page with a map.

That’s all good, but I found myself wishing that I could just have those enhancements. Every single navigation on the site was triggering a fade in and out—the default animation. I wondered if there was a way to switch off the default fading.

There is! That default animation is happening on a view transition named root. You can get rid of it with this snippet of CSS:

::view-transition-image-pair(root) {
  isolation: auto;
}
::view-transition-old(root),
::view-transition-new(root) {
  animation: none;
  mix-blend-mode: normal;
  display: block;
}

Voila! Now only the view transitions that you name yourself will get applied.

You can adjust the timing, the easing, and the animation properites of your view transitions. Personally, I was happy with the default morph.

In fact, that’s one of the things I like about this API. It’s another good example of declarative design. I say what I want to happen, but I don’t need to specify the details. I’ll let the browser figure all that out.

That’s what’s got me so excited about this API. Yes, it’s powerful. But just as important, it’s got a very low barrier to entry.

Chris has gathered a bunch of examples together in his post Early Days Examples of View Transitions. Have a look around to get some ideas.

If you like what you see, I highly encourage you to add view transitions to your website now.

“But wait,” I hear you cry, “this isn’t supported in any public-facing browser yet!”

To which, I respond “So what?” It’s a perfect example of progressive enhancement. Adding one meta element and a smidgen of CSS will do absolutely no harm to your website. And while no-one will see your lovely view transitions yet, once browsers do start shipping with support for the API, your site will automatically get better.

Your website will be enhanced. Progressively.

Update: Simon Pieters quite rightly warns against adding view transitions to live sites before the API is done:

in general, using features before they ship in a browser isn’t a great idea since it can poison the feature with legacy content that might break when the feature is enabled. This has happened several times and renames or so were needed.

Good point. I must temper my excitement with pragmatism. Let me amend my advice:

I highly encourage you to experiment with view transitions on your website now.

Inside the Globus INK: a mechanical navigation computer for Soviet spaceflight

The positively steampunk piece of hardware used for tracking Alexei Leonov’s Apollo-Soyuz mission.

I’ve always liked the idea that your website can be your API. Like, you’ve already got URLs to identify resources, so why not make that URL structure predictable and those resources parsable?

That’s why the (read-only) API for The Session doesn’t live at a separate subdomain. It uses the same URL structure as the regular site, but you can request the resources in an alternative format: JSON, XML, RSS.

This works out pretty well, mostly because I put a lot of thought into the URL structure of the site. I’m something of a URL fetishist, but I think that taking a URL-first approach to information architecture can be a good exercise.

Most of the resources on The Session involve nouns like tunes, events, discussions, and so on. There’s a consistent and predictable structure to the URLs for those sections:

• /things
• /things/new
• /things/search

And then an idividual item can be found at:

• things/ID

That’s all nice and predictable and the naming of the URLs matches what you’d expect to find:

• tunes
• tunes/new
• tunes/search?q=Ireland
• tunes/320

Tunes, events, discussions, sessions. Those are all fine. But there’s one section of the site that has this root URL:

/recordings

When I was coming up with the URL structure twenty years ago, it was clear what you’d find there: track listings for albums of music. No one would’ve expected to find actual recordings of music available to listen to on-demand. The bandwidth constraints and technical limitations of the time made that clear.

Two decades on, the situation has changed. Now someone new to the site might well expect to hit a link called “recordings” and expect to hear actual recordings of music.

So I should probably change the label on the link. I don’t think “albums” is quite right—what even is an album any more? The word “discography” is probably the most appropriate label.

Here’s my dilemma: if I update the label, should I also update the URL structure?

Right now, the section of the site with /tunes URLs is labelled “tunes”. The section of the site with /events URLs is labelled “events”. Currently the section of the site with /recordings URLs is labelled “recordings”, but may soon be labelled “discography”.

If you click on “tunes”, you end up at /tunes. But if you click on “discography”, you end up at /recordings.

Is that okay? Am I the only one that would be bothered by that?

I could update the URLs to match the labelling (with redirects for the old URLs, of course), but I’m not so keen on this URL structure:

• /discography
• /discography/new
• /discography/search
• /discography/ID

It doesn’t seem as tidy as:

• /recordings
• /recordings/new
• /recordings/search
• /recordings/ID

But if I don’t update the URLs to match the label, then I’m just going to have to live with the mismatch.

I’m just thinking out loud here. I think I should definitely update the label. I just won’t make any decision on changing URLs for a while yet.

Gerry talks about “top tasks” a lot. He literally wrote the book on it:

Top tasks are what matter most to your customers.

Seems pretty obvious, right? But it’s actually pretty rare to see top tasks presented any differently than other options.

Look at the global navigation on most websites. Typically all the options are given equal prominence. Even the semantics under the hood often reflect this egalitarian ideal, with each list in an unordered list. All the navigation options are equal, but I bet that the reality for most websites is that some navigation options are more equal than others.

I’ve been guilty of this on The Session. The site-wide navigation shows a number of options: tunes, events, discussions, etc. Each one is given equal prominence, but I can tell you without even looking at my server logs that 90% of the traffic goes to the tunes section—that’s the beating heart of The Session. That’s why the home page has a search form that defaults to searching for tunes.

I wanted the navigation to reflect the reality of what people are coming to the site for. I decided to make the link to the tunes section more prominent by bumping up the font size a bit.

I was worried about how weird this might look; we’re so used to seeing all navigation items presented equally. But I think it worked out okay (though it might take a bit of getting used to if you’re accustomed to the previous styling). It helps that “tunes” is a nice short word, so bumping up the font size on that word doesn’t jostle everything else around.

I think this adjustment is working well for this situation where there’s one very clear tippy-top task. I wouldn’t want to apply it across the board, making every item in the navigation proportionally bigger or smaller depending on how often it’s used. That would end up looking like a ransom note.

But giving one single item prominence like this tweaks the visual hierarchy just enough to favour the option that’s most likely to be what a visitor wants.

That last bit is crucial. The visual adjustment reflects what visitors want, not what I want. You could adjust the size of a navigation option that you want to drive traffic to, but in the long run, all you’re going to do is train people to trust your design less.

You don’t get to decide what your top task is. The visitors to your website do. Trying to foist an arbitrary option on them would be the tail wagging the dog.

Anway, I’m feeling a lot better about the site-wide navigation on The Session now that it reflects reality a little bit more. Heck, I may even bump that font size up a little more.

Improving the information architecture of the Smart Pension member app | Design and tech | Smart – retirement, savings and financial wellbeing

Here’s a really excellent, clearly-written case study that unfortunately includes this accurate observation:

In recent years the practice of information architecture has fallen out of fashion, which is a shame as you can’t design something successfully without it. If a user can’t find a feature, it’s game over - the feature may as well not exist as far as they’re concerned.

I also like this insight:

Burger menus are effective… at hiding things.

Balisage: Metaphors We Code By

My talk, Building, was about the metaphors we use to talk about the work we do on the web. So I’m interested in this analysis of the metaphors used to talk about markup:

• Data is documents, processing data is clerking
• Data is trees, processing data is forestry
• Data is buildings, processing data is construction
• Data is a place, processing data is a journey
• Data is a fluid, processing data is plumbing
• Data is a textile, processing data is weaving
• Data is music, processing data is performing

I was talking to someone recently about a forgotten battle in the history of the early web. It was a battle between search engines and directories.

These days, when the history of the web is told, a whole bunch of services get lumped into the category of “competitors who lost to Google search”: Altavista, Lycos, Ask Jeeves, Yahoo.

But Yahoo wasn’t a search engine, at least not in the same way that Google was. Yahoo was a directory with a search interface on top. You could find what you were looking for by typing or you could zero in on what you were looking for by drilling down through a directory structure.

Yahoo wasn’t the only directory. DMOZ was an open-source competitor. You can still experience it at DMOZlive.com:

The official DMOZ.com site was closed by AOL on February 17th 2017. DMOZ Live is committed to continuing to make the DMOZ Internet Directory available on the Internet.

Search engines put their money on computation, or to use today’s parlance, algorithms (or if you’re really shameless, AI). Directories put their money on humans. Good ol’ information architecture.

It turned out that computation scaled faster than humans. Search won out over directories.

Now an entire generation has been raised in the aftermath of this battle. Monica Chin wrote about how this generation views the world of information:

Catherine Garland, an astrophysicist, started seeing the problem in 2017. She was teaching an engineering course, and her students were using simulation software to model turbines for jet engines. She’d laid out the assignment clearly, but student after student was calling her over for help. They were all getting the same error message: The program couldn’t find their files.

Garland thought it would be an easy fix. She asked each student where they’d saved their project. Could they be on the desktop? Perhaps in the shared drive? But over and over, she was met with confusion. “What are you talking about?” multiple students inquired. Not only did they not know where their files were saved — they didn’t understand the question.

Gradually, Garland came to the same realization that many of her fellow educators have reached in the past four years: the concept of file folders and directories, essential to previous generations’ understanding of computers, is gibberish to many modern students.

Dr. Saavik Ford confirms:

We are finding a persistent issue with getting (undergrad, new to research) students to understand that a file/directory structure exists, and how it works. After a debrief meeting today we realized it’s at least partly generational.

We live in a world ordered only by search:

While some are quite adept at using labels, tags, and folders to manage their emails, others will claim that there’s no need to do because you can easily search for whatever you happen to need. Save it all and search for what you want to find. This is, roughly speaking, the hot mess approach to information management. And it appears to arise both because search makes it a good-enough approach to take and because the scale of information we’re trying to manage makes it feel impossible to do otherwise. Who’s got the time or patience?

There are still hold-outs. You can prise files from Scott Jenson’s cold dead hands.

More recently, Linus Lee points out what we’ve lost by giving up on directory structures:

Humans are much better at choosing between a few options than conjuring an answer from scratch. We’re also much better at incrementally approaching the right answer by pointing towards the right direction than nailing the right search term from the beginning. When it’s possible to take a “type in a query” kind of interface and make it more incrementally explorable, I think it’s almost always going to produce a more intuitive and powerful interface.

Directory structures still make sense to me (because I’m old) but I don’t have a problem with search. I do have a problem with systems that try to force me to search when I want to drill down into folders.

I have no idea what Google Drive and Dropbox are doing but I don’t like it. They make me feel like the opposite of a power user. Trying to find a file using their interfaces makes me feel like I’m trying to get a printer to work. Randomly press things until something happens.

Anyway. Enough fist-shaking from me. I’m going to ponder Linus’s closing words. Maybe defaulting to a search interface is a cop-out:

Text search boxes are easy to design and easy to add to apps. But I think their ease on developers may be leading us to ignore potential interface ideas that could let us discover better ideas, faster.

How to progressively enhance a nav menu | Go Make Things

A lot of folks assume that progressive enhancement means having to write the same code twice, but often, it can be as simple as extending the pattern you already have once the JS loads.

It’s said that the best way to learn about something is to teach it. I certainly found that to be true when I was writing the web.dev course on responsive design.

I felt fairly confident about some of the topics, but I felt somewhat out of my depth when it came to some of the newer modern additions to browsers. The last few modules in particular were unexplored areas for me, with topics like screen configurations and media features. I learned a lot about those topics by writing about them.

Best of all, I got to put my new-found knowledge to use! Here’s how…

The Session is a progressive web app. If you add it to the home screen of your mobile device, then when you launch the site by tapping on its icon, it behaves just like a native app.

In the web app manifest file for The Session, the display-mode property is set to “standalone.” That means it will launch without any browser chrome: no address bar and no back button. It’s up to me to provide the functionality that the browser usually takes care of.

So I added a back button in the navigation interface. It only appears on small screens.

Do you see the assumption I made?

I figured that the back button was most necessary in the situation where the site had been added to the home screen. That only happens on mobile devices, right?

Nope. If you’re using Chrome or Edge on a desktop device, you will be actively encourged to “install” The Session. If you do that, then just as on mobile, the site will behave like a standalone native app and launch without any browser chrome.

So desktop users who install the progressive web app don’t get any back button (because in my CSS I declare that the back button in the interface should only appear on small screens).

I was alerted to this issue on The Session:

It downloaded for me but there’s a bug, Jeremy - there doesn’t seem to be a way to go back.

Luckily, this happened as I was writing the module on media features. I knew exactly how to solve this problem because now I knew about the existence of the display-mode media feature. It allows you to write media queries that match the possible values of display-mode in a web app manifest:

.goback {
  display: none;
}
@media (display-mode: standalone) {
  .goback {
    display: inline;
  }
}

Now the back button shows up if you “install” The Session, regardless of whether that’s on mobile or desktop.

Previously I made the mistake of inferring whether or not to show the back button based on screen size. But the display-mode media feature allowed me to test the actual condition I cared about: is this user navigating in standalone mode?

If I hadn’t been writing about media features, I don’t think I would’ve been able to solve the problem. It’s a really good feeling when you’ve just learned something new, and then you immediately find exactly the right use case for it!

I think I’ve found some more strange service worker behaviour in Chrome.

It all started when I was checking out the very nice new redesign of WebPageTest. I figured while I was there, I’d run some of my sites through it. I passed in a URL from The Session. When the test finished, I noticed that the “screenshot” tab said that something was being logged to the console. That’s odd! And the file doing the logging was the service worker script.

I fired up Chrome (which isn’t my usual browser), and started navigating around The Session with dev tools open to see what appeared in the console. Sure enough, there was a failed fetch attempt being logged. The only time my service worker script logs anything is in the catch clause of fetching pages from the network. So Chrome was trying to fetch a web page, failing, and logging this error:

The service worker navigation preload request failed with a network error.

But all my pages were loading just fine. So where was the error coming from?

After a lot of spelunking and debugging, I think I’ve figured out what’s happening…

First of all, I’m making use of navigation preloads in my service worker. That’s all fine.

Secondly, the website is a progressive web app. It has a manifest file that specifies some metadata, including start_url. If someone adds the site to their home screen, this is the URL that will open.

Thirdly, Google recently announced that they’re tightening up the criteria for displaying install prompts for progressive web apps. If there’s no network connection, the site still needs to return a 200 OK response: either a cached copy of the URL or a custom offline page.

So here’s what I think is happening. When I navigate to a page on the site in Chrome, the service worker handles the navigation just fine. It also parses the manifest file I’ve linked to and checks to see if that start URL would load if there were no network connection. And that’s when the error gets logged.

I only noticed this behaviour because I had specified a query string on my start URL in the manifest file. Instead of a start_url value of /, I’ve set a start_url value of /?homescreen. And when the error shows up in the console, the URL being fetched is /?homescreen.

Crucially, I’m not seeing a warning in the console saying “Site cannot be installed: Page does not work offline.” So I think this is all fine. If I were actually offline, there would indeed be an error logged to the console and that start_url request would respond with my custom offline page. It’s just a bit confusing that the error is being logged when I’m online.

I thought I’d share this just in case anyone else is logging errors to the console in the catch clause of fetches and is seeing an error even when everything appears to be working fine. I think there’s nothing to worry about.

Update: Jake confirmed my diagnosis and agreed that the error is a bit confusing. The good news is that it’s changing. In Chrome Canary the error message has already been updated to:

DOMException: The service worker navigation preload request failed due to a network error. This may have been an actual network error, or caused by the browser simulating offline to see if the page works offline: see https://w3c.github.io/manifest/#installability-signals

Much better!

In Praise of the Unambiguous Click Menu | CSS-Tricks

What’s important is that you test it with real users… and stop using hover menus.

Strong agree!

Skipping skip links ⚒ Nerd

Vasilis offers some research that counters this proposal.

It makes much more sense to start each page with the content people expect on that page. Right? And if you really need navigation (which is terribly overrated if you ask me) you can add it in the footer. Which is the correct place for metadata anyway.

That’s what I’ve done on The Session.