This would be such a great addition to CSS—a parent/ancestor selector!
With the combined might of
calc(), CSS has become a powerful language for specifying rules to account for all kinds of situations.
This would be such a great addition to CSS—a parent/ancestor selector!
With the combined might of
calc(), CSS has become a powerful language for specifying rules to account for all kinds of situations.
There’s a good discussion here (kicked off by Jen) about providing different
theme-color values in a web app manifest to match
prefers-color-scheme in media queries.
It would be nice to be able to animate the transition between pages if we want to on the web without resorting to hacks or full-blown architecture choices to achieve it.
Amen, Chris, amen!
The danger here is that you might pick a single-page app just for this ability, which is what I mean by having to buy into a site architecture just to achieve this.
I’ve always liked the way that web browsers are called “user agents” in the world of web standards. It’s such a succinct summation of what browsers are for, or more accurately who browsers are for. Users.
The term makes sense when you consider that the internet is for end users. That’s not to be taken for granted. This assertion is now enshrined in the Internet Engineering Task Force’s RFC 8890—like Magna Carta for the network age. It’s also a great example of prioritisation in a design principle:
When there is a conflict between the interests of end users of the Internet and other parties, IETF decisions should favor end users.
So when a web browser—ostensibly an agent for the user—prioritises user-hostile third parties, we get upset.
Google Chrome—ostensibly an agent for the user—is running an origin trial for Federated Learning of Cohorts (FLoC). This is not a technology that serves the end user. It is a technology that serves third parties who want to target end users. The most common use case is behavioural advertising, but targetting could be applied for more nefarious purposes.
The Electronic Frontier Foundation wrote an explainer last month: Google Is Testing Its Controversial New Ad Targeting Tech in Millions of Browsers. Here’s What We Know.
Let’s back up a minute and look at why this is happening. End users are routinely targeted today (for behavioural advertising and other use cases) through third-party cookies. Some user agents like Apple’s Safari and Mozilla’s Firefox are stamping down on this, disabling third party cookies by default.
Seeing which way the wind is blowing, Google’s Chrome browser will also disable third-party cookies at some time in the future (they’re waiting to shut that barn door until the fire is good’n’raging). But Google isn’t just in the browser business. Google is also in the ad tech business. So they still want to advertisers to be able to target end users.
Yes, this is quite the cognitive dissonance: one part of the business is building a user agent while a different part of the company is working on ways of tracking end users. It’s almost as if one company shouldn’t simultaneously be the market leader in three separate industries: search, advertising, and web browsing. (Seriously though, I honestly think Google’s search engine would get better if it were split off from the parent company, and I think that Google’s web browser would also get better if it were a separate enterprise.)
Anyway, one possible way of tracking users without technically tracking individual users is to assign them to buckets, or cohorts of interest based on their browsing habits. Does that make you feel safer? Me neither.
That’s what Google is testing with the origin trial of FLoC.
If you, as an end user, don’t wish to be experimented on like this, there are a few things you can do:
That last decision is interesting. On the one hand, the origin trial is supposed to be on a small scale, hence the lack of European countries. On the other hand, the origin trial is “opt out” instead of “opt in” so that they can gather a big enough data set. Weird.
The plan is that if and when FLoC launches, websites would have to opt in to it. And when I say “plan”, I mean “best guess.”
I, for one, am filled with confidence that Google would never pull a bait-and-switch with their technologies.
In the meantime, if you’re a website owner, you have to opt your website out of the origin trial. You can do this by sending a server header. A
meta element won’t do the trick, I’m afraid.
I’ve done it for my sites, which are served using Apache. I’ve got this in my
<IfModule mod_headers.c> Header always set Permissions-Policy "interest-cohort=()" </IfModule>
If you don’t have access to your server, tough luck. But if your site runs on Wordpress, there’s a proposal to opt out of FLoC by default.
Interestingly, none of the Chrome devs that I follow are saying anything about FLoC. They’re usually quite chatty about proposals for potential standards, but I suspect that this one might be embarrassing for them. It was a similar situation with AMP. In that case, Google abused its monopoly position in search to blackmail publishers into using Google’s format. Now Google’s monopoly in advertising is compromising the integrity of its browser. In both cases, it makes it hard for Chrome devs claiming to have the web’s best interests at heart.
But one of the advantages of having a huge share of the browser market is that Chrome can just plough ahead and unilaterily implement whatever it wants even if there’s no consensus from other browser makers. So that’s what Google is doing with FLoC. But their justification for doing this doesn’t really work unless other browsers play along.
The problem is with step three. The theory is that if FLoC gives third parties what they need, then they won’t reach for fingerprinting. Even if there were any validity to that hypothesis, the only chance it has of working is if every browser joins in with FLoC. Otherwise ad tech companies are leaving money on the table. Can you seriously imagine third parties deciding that they just won’t target iPhone or iPad users any more? Remember that Safari is the only real browser on iOS so unless FLoC is implemented by Apple, third parties can’t reach those people …unless those third parties use fingerprinting instead.
Google have set up a situation where it looks like FLoC is going head-to-head with fingerprinting. But if FLoC becomes a reality, it won’t be instead of fingerprinting, it will be in addition to fingerprinting.
Google is quite right to point out that fingerprinting is A Very Bad Thing. But their concerns about fingerprinting sound very hollow when you see that Chrome is pushing ahead and implementing a raft of browser APIs that other browser makers quite rightly point out enable more fingerprinting: Battery Status, Proximity Sensor, Ambient Light Sensor and so on.
When it comes to those APIs, the message from Google is that fingerprinting is a solveable problem.
But when it comes to third party tracking, the message from Google is that fingerprinting is inevitable and so we must provide an alternative.
Which one is it?
Google’s flimsy logic for why FLoC is supposedly good for end users just doesn’t hold up. If they were honest and said that it’s to maintain the status quo of the ad tech industry, it would make much more sense.
The flaw in Google’s reasoning is the fundamental idea that tracking is necessary for advertising. That’s simply not true. Sacrificing user privacy is fundamental to behavioural advertising …but behavioural advertising is not the only kind of advertising. It isn’t even a very good kind of advertising.
FLoC seems to be Google’s way of saving a dying business. They are trying to keep targeted ads going by making them more “privacy-friendly” and “anonymous”. But behavioral profiling and targeted advertisement is not compatible with a privacy-respecting web.
What’s striking is that the very monopolies that make Google and Facebook the leaders in behavioural advertising would also make them the leaders in contextual advertising. Almost everyone uses Google’s search engine. Almost everyone uses Facebook’s social network. An advertising model based on what you’re currently looking at would keep Google and Facebook in their dominant positions.
Google made their first many billions exclusively on contextual advertising. Google now prefers to push the message that behavioral advertising based on personal data collection is superior but there is simply no trustworthy evidence to that.
I sincerely hope that Chrome will align with Safari, Firefox, Vivaldi, Brave, Edge and every other web browser. Everyone already agrees that fingerprinting is the real enemy. Imagine the combined brainpower that could be brought to bear on that problem if all browsers made user privacy a priority.
Until that day, I’m not sure that Google Chrome can be considered a user agent.
It’s heavy on computer science, but this is a fascinating endeavour. It’s a work-in-progress book that not only describes how browsers work, but invites you to code along too. At the end, you get a minimum viable web browser (and more knowledge than you ever wanted about how browsers work).
As a black box, the browser is either magical or frustrating (depending on whether it is working correctly or not!). But that also make a browser a pretty unusual piece of software, with unique challenges, interesting algorithms, and clever optimizations. Browsers are worth studying for the pure pleasure of it.
See how the sausage is made and make your own sausage!
Receive one email a day for 30 days, each featuring at least one HTML element.
Right up my alley!
Good to see Google, Mozilla, and Apple collaborating on fixing cross-browser CSS compatability issues:
You can track progress here.
Given the widespread browser support for
prefers-reduced-motion now, this approach makes a lot of sense.
I really enjoyed this 20 minute chat with Eric and Rachel all about web standards, browsers, HTML and CSS.
It’s official. The extremely niche browser behaviour I documented is a bug.
Oh boy, do I have some obscure browser behaviour for you!
To set the scene…
I’ve been writing here in my online journal for almost twenty years. The official anniversary will be on September 30th. But this website has been even online longer than that, just in a very different form.
Here’s the first version of adactio.com.
Like a tour guide taking you around the ruins of some lost ancient civilisation, let me point out some interesting features:
.shtmlfile extension. That means it was once using Apache’s server-side includes, a simple way of repeating chunks of markup across pages. Scientists have been trying to reproduce the wisdom of the ancients using modern technology ever since.
100vh? Well, this was long before viewport units existed. In fact there is no CSS at all on that page. It’s one big
tableelement with 100% width and 100% height.
border-radiuscoming from? Let me introduce you to an old friend—the non-animated GIF. It’s got just enough transparency (though not proper alpha transparency) to fake rounded corners between two solid colours.
if (navigator.appName == "Netscape")
Note that these are not iframes, they are frames. Different thing. You could create single page apps long before Ajax was a twinkle in Jesse James Garrett’s eye.
If you view source, you’ll see a React-like component system. Each
frameset component contains
frame components that are isolated from one another. They’re like web components. Each frame has its own (non-shadow) DOM. That’s because each frame is actually a separate web page. If you right-click on any of the frames, your browser should give the option to view the framed document in its own tab or window.
Now for the part where modern and ancient technologies collide…
If you’re looking at the frameset URL in Firefox or Safari, everything displays as it should in all its ancient glory. But if you’re looking in Google Chrome and you’ve visited adactio.com before, something very odd happens.
Each frame of the frameset displays my custom offline page. The only way that could be served up is through my service worker script. You can verify this by opening the framest URL in an incognito window—everything works fine when no service worker has been registered.
I have no idea why this is happening. My service worker logic is saying “if there’s a request for a web page, try fetching it from the network, otherwise look in the cache, otherwise show an offline page.” But if those page requests are initiated by a
frame element, it goes straight to showing the offline page.
Is this a bug? Or perhaps this is the correct behaviour for some security reason? I have no idea.
I wonder if anyone has ever come across this before. It’s a very strange combination of factors:
I could submit a bug report about this but I fear I would be laughed out of the bug tracker.
Still …the World Wide Web is remarkable for its backward compatibility. This behaviour is unusual because browser makers are at pains to support existing content and never break the web.
Technically a modern website (one that registers a service worker) shouldn’t be using deprecated technology like frames. But browsers still need to be able support those old technologies in order to render old websites.
This situation has only arisen because the same domain—adactio.com—is host to a modern website and a really old one.
Maybe Chrome is behaving strangely because I’ve built my online home on ancient burial ground.
It’s all to do with navigation preloads and the value of
event.preloadResponse, which I believe is only supported in Chrome which would explain the differences between browsers.
According to this post by Jake:
event.preloadResponse is a promise that resolves with a response, if:
- Navigation preload is enabled.
- The request is a GET request.
- The request is a navigation request (which browsers generate when they’re loading pages, including iframes).
event.preloadResponseis still there, but it resolves with
Notice that iframes are mentioned, but not frames.
My code was assuming that if
event.preloadRepsonse exists in my block of code for responding to page requests, then there’d be a response. But if the request was initiated from a frameset, it is a request for a page and
event.preloadRepsonse does exist …but it’s undefined.
I’ve updated my code now to check this assumption (and fall back to
This may technically still be a bug though. Shouldn’t a page loaded from a frameset count as a navigation request?
I like this proposal, and I like that it’s polyfillable (which is a perfectly cromulent word).
I’m very taken with Github’s tab-container element—this is exactly how I think web components should be designed!
Two-factor authentication is generally considered A Good Thing™️ when you’re logging in to some online service.
The word “factor” here basically means “kind” so you’re doing two kinds of authentication. Typical factors are:
Asking for a password and an email address isn’t two-factor authentication. They’re two pieces of identification, but they’re the same kind (something you know). Same goes for supplying your fingerprint and your face: two pieces of information, but of the same kind (something you are).
None of these kinds of authentication are foolproof. All of them can change. All of them can be spoofed. But when you combine factors, it gets a lot harder for an attacker to breach both kinds of authentication.
The most common kind of authentication on the web is password-based (something you know). When a second factor is added, it’s often connected to your phone (something you have).
Every security bod I’ve talked to recommends using an authenticator app for this if that option is available. Otherwise there’s SMS—short message service, or text message to most folks—but SMS has a weakness. Because it’s tied to a phone number, technically you’re only proving that you have access to a SIM (subscriber identity module), not a specific phone. In the US in particular, it’s all too easy for an attacker to use social engineering to get a number transferred to a different SIM card.
Still, authenticating with SMS is an option as a second factor of authentication. When you first sign up to a service, as well as providing the first-factor details (a password and a username or email address), you also verify your phone number. Then when you subsequently attempt to log in, you input your password and on the next screen you’re told to input a string that’s been sent by text message to your phone number (I say “string” but it’s usually a string of numbers).
There’s an inevitable friction for the user here. But then, there’s a fundamental tension between security and user experience.
In the world of security, vigilance is the watchword. Users need to be aware of their surroundings. Is this web page being served from the right domain? Is this email coming from the right address? Friction is an ally.
But in the world of user experience, the opposite is true. “Don’t make me think” is the rallying cry. Friction is an enemy.
With SMS authentication, the user has to manually copy the numbers from the text message (received in a messaging app) into a form on a website (in a different app—a web browser). But if the messaging app and the browser are on the same device, it’s possible to improve the user experience without sacrificing security.
If you’re building a form that accepts a passcode sent via SMS, you can use the
autocomplete attribute with a value of “one-time-code”. For a six-digit passcode, your
input element might look something like this:
<input type="text" maxlength="6" inputmode="numeric" autocomplete="one-time-code">
With one small addition to one HTML element, you’ve saved users some tedious drudgery.
There’s one more thing you can do to improve security, but it’s not something you add to the HTML. It’s something you add to the text message itself.
Let’s say your website is example.com and the text message you send reads:
Your one-time passcode is 123456.
Add this to the end of the text message:
So the full message reads:
Your one-time passcode is 123456. @example.com #123456
The first line is for humans. The second line is for machines. Using the @ symbol, you’re telling the device to only pre-fill the passcode for URLs on the domain example.com. Using the # symbol, you’re telling the device the value of the passcode. Combine this with
autocomplete="one-time-code" in your form and the user shouldn’t have to lift a finger.
I’m fascinated by these kind of emergent conventions in text messages. Remember that the @ symbol and # symbol in Twitter messages weren’t ideas from Twitter—they were conventions that users started and the service then adopted.
You can add a URL for
/.well-known/change-password which redirects to the form a user would use to update their password. Browsers and password managers can then use this information if they need to prompt a user to update their password after a breach. I’ve added this to The Session.
Oh, and on that page where users can update their password, the
autocomplete attribute is your friend again:
<input type="password" autocomplete="new-password">
If you want them to enter their current password first, use this:
<input type="password" autocomplete="current-password">
All of the things I’ve mentioned—the
autocomplete attribute, origin-bound one-time codes in text messages, and a well-known URL for changing passwords—have good browser support. But even if they were only supported in one browser, they’d still be worth adding. These additions do absolutely no harm to browsers that don’t yet support them. That’s progressive enhancement.
mediasupport from HTML video was a mistake.
Damn right! It was basically Hixie throwing a strop, trying to sabotage responsive images. Considering how hard it is usually to remove a shipped feature from browsers, it’s bizarre that a good working feature was pulled out of production.
This sounds a lot like Do Not Track …but looking at the spec, the interesting part is the way that this is designed to work in combination with legal frameworks. That’s smart. I don’t think a purely technical solution is workable (as we saw with Do Not Track).
This is a very thoughtful and measured response to Alex’s post Platform Adjacency Theory.
Unlike Alex, the author doesn’t fire off cheap shots.
Also, I’m really intrigued by the idea of certificate authorities for hardware APIs.
storage.estimate() in service workers to figure out how much gets pre-cached.
I really enjoyed this trip down memory lane with Chris:
From the Web’s inception, an ancient to contemporary history of the Web.