Is it reasonable to assume my visitors have javascript enabled?

Question

I understand that server-side validation is an absolute must to prevent malicious users (or simply users who choose to disable javascript) from bypassing client-side validation. But that's mainly to protect your application, not to provide value for those who are running browsers with javascript disabled. Is it reasonable to assume visitors have javascript enabled and simply have an unusable site for those who don't?

Answer 1

It is ok in these days to assume your visitors have JS enabled. With that said, you should strive for the best possible degradation of your site with JS disabled. It is ideal if your site falls back to a state that is still usable without JS.

Answer 2

Yes it is. But expose as much of it as possible through regular HTML and URLs, if for nothing else than for Google.

Answer 3

Accessible, yes... functional? Not really.

This is really a customer requirement question more than developer-answerable, but if your customer tries to enforce a requirement that non-JS browsers work, you should argue heavily against it and really hammer them on the "cool" factor they'll be missing.

Given the heavy reliance by GWT, RichFaces, etc. on Javascript, it's just not feasible to make an app with any kind of user-friendly UI without it.

You should certainly warn non-JS enabled users that the site they're trying to visit relies heavily on JS, though. No point in being rude about it.

Answer 4

I think there is another reason which push you to support at least some main functionality without JS - lots of us now browsing from mobile and PDA, which have no the same lvl of JavaScript support.

Answer 5

I browse with NoScript in Firefox, and it always annoys me when I get pages that don't work. That said - know your audience. If you're trying to cater to paranoid computer security professionals - assume they might not have JavaScript enabled. If you're going for a general audience, JavaScript is probably on.

Answer 6

http://www.w3schools.com/browsers/browsers_stats.asp

They claim 95% of users have Javascript on.

Answer 7

Duplicate

There's at least one category where the answer is definitely "no". If you work for the government, you must make sure the site is accessible to those using screen readers.

Answer 8

I think it's fair to assume that the majority of visitors to your site will have JavaScript enabled. Some of the more trafficked sites out there have a dependency on JavaScript. For example, I was surprised to learn that you can't authenticate through a Passport-enabled site without a JS-enabled browser.

Answer 9

No its not, period, full-stop, end of story. Its just naive and wrong at an ethical level, not to mention you miss out on around 50% of Internet users worldwide (believe it or not 70% of web access worldwide is from mobile devices).

Add extra nifty stuff that requires Javascript, thats fine. Don't make your site unusable without Javascript unless you have really, really, really good reason to do so.

Someone rightly pointed out that I don't have evidence to back up my claim of 70% mobile web users. Unforunately I can't find the source I got it from but I remember it being authorative so have no reason to doubt it. It does make sense though when you consider worldwide usage, many developing countries have more mobile phones than landlines and broadband. A statistic that was quoted in my not-to-be-found source was that one African country in particular has 300,000 landlines, but has 1.5 million mobile phones!

Answer 10

Nearly all (but not quite all!) users will have javascript enabled. (I believe the figure quoted above of about 5% is accurate.)

Given the vast improvement in usability you can make with the judicious use of javascript, my opinion is that most of the time, it is reasonable to assume it is enabled.

There will of course be some instances where that is not the case, (ie, a site designed for mobile devices, or with a high percentage of disabled users etc), and always a effort should definitely be given to making your site as accessible as possible to as large a percentage of the population as possible.

That said, if you only have a low traffic site, 5% of a small number is a very small number. It may not be worth bending over backwards to make your site accessible to these people when it may only gain you one or two extra users.

I guess the short answer is (as always), there is no correct answer - it will depend entirely on the target use, and target users of the sit in question.

Answer 11

According to this little page Javascript is enabled in 95% of browsers and it keeps raising.

Answer 12

Totally depends on who you're aiming at.

If your site or app is for an Intranet, you can make lots of assumptions. If your target audience is bleeding-edge social-networking types, you can assume JavaScript will work. If you anticipate a lot of paranoia sysadmin types, you can assume a bunch of them will be trying to access your site in lynx or have JS turned of for "security reasons."

A good example of this is Amazon -- their approach is driven by their business goals. They are a mass-market site, but for them, locking out users in old/incapable browsers means potential lost sales, so they work hard on non-script fallbacks.

So like lots of these kinds of questions, the answer is not just regurgitating what you've read somewhere about accessibility or progressive enhancement. The real answer is "it depends."

Answer 13

The W3C Browser Statistics page (scroll down) has some information on this; they say that 95% of visitors have JavaScript on as of January 2008.

Answer 14

It's reasonable to assume your visitors have javascript enabled !-)

-- but of course it depends on who you're trying to reach ...

Several times above w3schools have been mentioned and, as Dan stated, its their own visitors which make it somewhat quirky to draw conclusion from.

However, if you look at theCounter.com it seems that their audience has the same habits in general on this point ...

A twist that hasn't been mentioned yet is the growing amount of crawlers, mailharvesters and so on, they definitely do not have javascript turned on, and how good are counters to detect them ?-)

My guess would be, that this sort of machine-browsers fill up a lot of those 5-6% !o]

-- that said, if it's at all possible, make your app degrade gracefully (as a wise man said)

Answer 15

Your questions seems to suggest form based input for an application. If it's an intranet application then you'd be guided by the in-house security experts. If it's public app, then as other posters have suggested, fail gracefully.

Answer 16

No! Some environments will have it disabled as a matter of policy, with nothing you can do to enable it. And even if it's enabled, it might be crippled.

This question has been asked before.

Answer 17

I will argue that it is more than reasonable to expect them to have javascript so long as you provide suitable means to replace javascript should it not be enabled. One of the reasons that I like the Yahoo UI Library is that it degrades gracefully.

Answer 18

One interesting point to consider is that as a web developer you have a social responsibility to push technology forward - and by using things like AJAX, you increase exposure and potentially rate of adoption along with it. The only thing that should stop you from using the tech to its fullest extent is money - if you won't make the money that you need because people will have trouble viewing the material, you've got to reconsider.

Answer 19

I browse with the NoScript plugin in firefox and I'm surprised at the amount of developers that haven't even considered making their site degradable.

Never assume the user has JavaScript disabled - especially seeing as it may not always be their fault. Many enterprises have firewalls which block JavaScript/ActiveX etc. - In this instance the <noscript> element won't work so I would NOT recomend using that either!

Unless you're creating a full-on web application which is going to be 90% Ajax then you must make sure to abide by standards and progressively enhance your site through various layers of interactivity.

Also don't forget the important of object detection, especially with the rise of mobile phone web browsing. One of the most popular mobile web browsers (Opera mini 4.0) doesn't allow all "Background javaScript" to work and Ajax calls rarely execute correctly... Just something to be aware of.

To be honest I am sick and tired of developers that think everyone will have JS enabled! What ignorance!!

Answer 20

I always try to code my sites as static one first, THEN i add js/ajax functionality. This way i can be kinda sure that will work on non JS browsers :)

But, javascript is like flash: all users have it, but developer have to concern on WHAT IF.... ? :D

Answer 21

This is totally a "it depends" question, as many people have pointed out.

This is why metrics is valuable on sites to help show if you can really run with the analogy that "major sites say that the majority of people have JS on" - you could have a site where it's 99%. I won't dig in to what's been said above, as it's been answered very well :)

Answer 22

Is it reasonable to assume visitors have javascript enabled and simply have an unusable site for those who don't?

There are actually two questions, and the answers are: Yes, it is reasonable to assume visitors have javascript enabled. And, No this does not mean others should be left with unusable site.

Progressive enhancement is the way to go. Have your site usable without javascript and then add bells and whistles.

As for client side validation, it is no more than a convenience for user to avoid unnecessary roundtrips to server (where real validation should be performed).

Answer 23

Never ever assume Javascript for form validation, as your question implies. Someone will eventually realise this and turn Javascript off.

Instead, code the app in fairly regular html manner and use Javascript for what it is: an optional perk for your users.

Even for an entirely AJAX app like Gmail, the complete works of form validation is required on the server side.