Tesla Model S Web Browser Capabilities

Tesla Model S Web Browser Capabilities

UPDATED FOR v5.9 (1.51.94) ON 4/8/14

Based on some discussion in the Prioritized Software Enhancement List thread, I decided to undertake an analysis of just what the car's built in web browser is capable of and what it isn't. It certainly is no powerhouse, but provides pretty accurate rendering while simultaneously offering poor HTML 5 support. Below are the sites I used and a summary of the results of the car, my iPhone 5 and Chrome on my desktop for comparison. Run them yourself if you want the full details.

Based on these results and my general usage of it, I'd like to see:

A faster JavaScript engine like the ones Chrome or FireFox uses
Full compatibility with the Acid 3 test (100 score)
Native support for common audio/video formats and PDF
A much better score on the HTML 5 feature tests
HTML 5 location services support
Better touch response/feedback when clicking links, it's too fiddly right now
Previous/Next buttons for navigating forms like the iPhone has
If a car API is ever developed, it would be nice to see (at least some of) it integrated as custom JavaScript APIs in the browser

With these things we could accomplish quite a lot for the car via simple web apps even without a formal API. Let the discussion begin!

Browser User Agent
What's My User Agent
Model S (3/13/13, v?.?) = Mozilla/5.0 (X11; U; Linux; C) AppleWebKit/533.3 (KHTML, like Gecko) QtCarBrowser Safari/533.3
Model S (4/8/14, v5.9) = Mozilla/5.0 (X11; Linux) AppleWebKit/534.34 (KHTML, like Gecko) QtCarBrowser Safari/534.34

JavaScript Performance
SunSpider 0.9.1 JavaScript Benchmark     * lower is better
Model S (3/13/13, v4.3) = 5085 msec
Model S (4/8/14, v5.9) = 3120 msec
iPhone 5 (3/13/13, iOS 6.1) = 979 msec
iPhone 5s (4/8/14, iOS 7.1) = 436 msec
Chrome (3/13/13, v25) = 203 msec
Chrome (4/8/14, v33) = 290 msec
(Yes, there's newer versions of SunSpider now but I kept with 0.9.1 to ensure comparable scores.)

Rendering Accuracy
Acid 3 Test     * higher is better (%)
Model S (3/13/13, v4.3) = 99
Model S (4/8/14, v5.9) = 100
iPhone 5 (3/13/13, iOS 6.1)= 100
iPhone 5s (4/8/14, iOS 7.1) = 100
Chrome (3/13/13, v25) = 100
Chrome (4/8/14, v33) = 100

Basic Capabilities
Model S =

Session cookies
Persistent cookies
JavaScript 1.5
SSL 128bit
Screen 1920x1200 - Available 1160x620 - 24bit color depth
File Upload     * I thought this was interesting...
Web Storage API (v5.9)
Geolocation API (v5.9)

HTML 5 Compatability
HTML 5 Test     * higher is better (490 max)
Model S (3/13/13, v4.3) = 181
Model S (4/8/14, v5.9) = 254
iPhone 5 (3/13/13, iOS 6.1)= 386
iPhone 5s (4/8/14, iOS 7.1) = 412
Chrome (3/13/13, v25) = 463
Chrome (4/8/14, v33) = 505

GeekEV | March 13, 2013

Oh, I'd also like to see previous/next buttons for navigating forms like the iPhone has...

olanmills | March 13, 2013

I want the refresh button to be easier to use, like the Favorites buttons are.

GeekEV | March 14, 2013

And a home button would be nice too now that I think about it...

riceuguy | March 14, 2013

PDF support is key for showing an officer proof of insurance. :-)

MandL | March 14, 2013

" JavaScript Performance
SunSpider JavaScript Benchmark * lower is better
Model S = 5085 msec
iPhone 5 = 979 msec
Chrime = 203 msec"

Are you implying that Google is doing something illegal with their browser to achieve these speeds? ;-)

jat | March 14, 2013

Yeah, I don't know why they would use KHTML rather than Chromium for the browser. I am guessing it has to do with the windowing environment, in that whatever windowing system they use had Qt integration but didn't have Cairo, but that seems like a poor choice. Chrome already supports ARM processors, and runs great on the Tegra already (in Android tablets).

My biggest gripe is actually the lack of persistent cookies (that span turning the car off). I presume the concern is about leaving session tokens for apps in the car where someone else could access them, but I think you could support a PIN if you care about that.

Docjay | March 14, 2013

This is all geek to me.

Sorry, couldn't resist. :)

Brian H | March 14, 2013

Translation: The TM browser is slower than molasses by industry standards, and probably isn't fixable.

jat | March 14, 2013

@BrianH - I don't know why you say it isn't fixable - it is just software, and the hardware it is running on is pretty reasonably powered (though nowhere else does it drive such a large screen, so it is likely going to always be slow in graphics-heavy tests).

Brian H | March 14, 2013

Probably need a different browser. A 5-second Javascript benchmark sucks rotten eggs.

mikhaila | March 14, 2013

Chrome, Safari, iPhone Safari are all based on the same engine. So Tesla probably just needs to upgrade browser to the laters WebKit

jat | March 14, 2013

@BrianH - sure, but that is doable. And before V8 came along and forced everyone to work on their JS performance, it wasn't uncommon for all the browsers to have multi-second SunSpider benchmarks. | March 14, 2013

Is this test fair? For example is the iPhone on a 4G LTE connection and Chrome directly connected via Internet? The connection speed may make a huge difference in performance, unrelated to the browser and local CPU? It may be the tests are entirely local (i.e. run after downloading), and then would be a perfect comparison test.

I suspect there is little chance of supporting video, due to legal requirements (I think) that do not allow video in sight of the driver while in motion (with the exception of the rear camera).

It's possible to make a design that allows video while in Park, but that also means Tesla modifications to the browser. I don't know if Tesla has source code access to the browser (and if it really wants to be in the custom browser business).

Any features or components that might allow video or something similar (i.e. games with motion) may also fall into these concerns, and is likely the reason various browser features are disabled.

Thanks for the detailed analysis - I'm sure there are still quite a few areas that could be implemented and/or improved without these concerns, like location services, audio, persistent cookies, etc.

Brad Holt | March 14, 2013

I know it doesn't play video and audio, and that's not going to change. A Tesla rep told me the government would not allow it, so even if the browser was made more capable, A/V will stay out of the picture. :/

Originally I had really hoped for some in-browser Pandora pleasure until the SDK was out. Oh well! I'll just be patient...again. :)

GeekEV | March 14, 2013

@riceuguy - Or you could just PRINT a copy... ;-)

@MandL - Oops. Fixed it.

@jat - Even Chromium reports KTHML. They all descend from it...

Mozilla/5.0 (Macintosh; Intel Mac OS X 10_8_2) AppleWebKit/537.22 (KHTML, like Gecko) Chrome/25.0.1364.172 Safari/537.22

Regarding the JavaScript speed, I believe the rendering engine and javascript are two different entities and is one of the key differences between Chrome and Safari.

@Frank2 - All of these tests are downloaded and run local to the browser. Bandwidth is not an issue. Regarding Tesla being in the custom browser business, if they were to open source large portions of the car's OS (no doubt some would have to be proprietary) we could do it for them...

@Brad - Video maybe, but audio? There's no reason for that. The car already plays terrestrial radio, satellite radio and internet radio...

jat | March 17, 2013

@Geek EV - I hadn't noticed Chrome reported KHTML as well, but still I don't know why they would choose any open-source WebKit browser besides Chrome. Yes, rendering and JS performance are almost entirely separate, and V8 is one of the key advantages of Chrome over Safari (which uses JSCore). That is also why Safari has had some really nasty JS bugs lately as they try and get performance up to V8.

studio3d | April 30, 2013

Are any updates to the browser performance area planned in the near future?

MattMSD | May 9, 2013

Can the browser play sound using javascript of HTML5?

jdonovan | June 17, 2013

I'm having trouble loading some web pages. Particularly pdf web pages e.g.,

Any suggestions?

jdonovan | June 17, 2013

Or even more importantly, pages like this youtube video of elon musk showing the model x:

eAdopter | June 17, 2013

I needed help from TM last week and the browser wouldn't allow a connection to where TM phone numbers are listed. Is this true for everyone or is it just my car?

sxross | June 17, 2013

Pretty much everyone has access to WebKit source and Mozilla source as they are open-source projects. However, it should be noted that each vendor who uses these typically injects their own customizations. For example, Google uses the V8 engine for Javascript interpretation. It's extremely fast and the benchmarks are isolated and don't rely on network speeds.

The short answer to the original question is:

* There may be room for improvement (when isn't there)
* it's a software deal
* technically it's achievable
* who knows what the priority of having a blazing fast Web browser in a car is.

The good news is that the user agent can be identified as a car Web browser so anyone who cares to modify a page for car display can. I suspect this is a pretty limited audience so don't hold your breath.

I'll hazard a guess that PDF relies on either native OS support (Apple) or plugin (Adobe), and it's not clear that the in-console browser app supports this kind of add-on. HTML 5 video could be supported if its legal. However, any flash-video or other proprietary formats would again rely on plugins.

I'll bring my iPhone or if I'm really in Web withdrawals, my iPad or MBP.

Brian H | June 17, 2013

Both load fine for me using FF. Try installing Foxit Reader for the pdf.

babs | August 4, 2013

When I bring up a web page and add it to my list of favorites, it does not show up in my list of favorites. My list of favorites is still empty. Am I doing something wrong?

Bob W | August 4, 2013

If you are tapping the Heart + button (second from right), it should add the current URL to your browser favorites. If you are pressing the Heart button (last on the right), it just displays your favorites list (without adding anything).

If tapping Heart+ doesn't work, reboot the 17" display (hold down both scroll wheels until the display goes black), and try again. If it still doesn't work, call service.

Xerogas | August 4, 2013


What software version does your car have? There's a bug in older versions that prevents favorites from being saved.

Bob W | August 4, 2013

Did anyone else notice that the Browser lost some capability when 4.5 was installed? I can no longer get pop-up data entry windows to work. They actually seem to hang the browser.

For example:

Go to (the very cool Tesla analog clock app.)
Tap Stocks at the bottom edge
Tap Edit Stocks, bottom right edge
Tap the big + icon to add a new one
Bug: the Model S browser hangs. Only a reboot of 17" display seems to cure it.

If you do the same steps on a real web browser, it displays a pop-up window where you can enter a stock symbol. That used to work OK on the Model S browser, but ever since 4.5 was installed, it does not.

I speculate that Tesla disabled all pop-up windows on 4.5, and this broke one of cool features of the Time4Tesla app., including the ability to customize your weather location (same issue, when tapping Choose Location, bottom right).

Workaround: copy the long random URL assigned to your car (take a photo if it), go to a real web browser, enter the exact same URL, and update your stock lists there, then save the changes. Return to the Model S and tap Refresh. The app. will display your updated stock list. You can do the same for your weather location.

But it would be better if we could do this in the car, like we used to.

Colasec | August 5, 2013

@BobW I noticed the same behavior when trying to set the weather location in that site and didn't understand what was going on. Thanks for posting an explanation and a workaround.

GeekEV | October 23, 2013

Other threads have also mentioned this, but since it's directly relevant to this thread I wanted to tag it here too. In a recent public appearance Elon indicated that the Model S would get app support (of some kind) and the Chrome browser towards the end of 2014. Now we're talkin'...

Of course, we don't know if that would be for existing cars or only new cars going forward. But I'm optimistic!

chrisdl | March 27, 2014

HTML 5 compatibility test is now at 254 (with 5.9, that is).

It would be great if you could keep a history per version in this thread. (Did I just say perversion? ;-)

Brian H | March 27, 2014

476 with XP desktop Opera, 448 with desktop Firefox.

chrisdl | March 28, 2014

Some more 5.9 information:

User Agent:
Mozilla/5.0 (X11; Linux) AppleWebKit/534.34 (KHTML, like Gecko) QtCarBrowser Safari/534.34

SunSpider 1.0.2:

Acid 3:

HTML 5 Test:

Seems like the JavaScript engine has doubled in speed. Not bad.

shop | March 28, 2014

"Seems like the JavaScript engine has doubled in speed. Not bad."

That is good news indeed. Hopefully the browser doesn't hang when viewing Google spreadsheets like the last version of the browser did.

chrisdl | April 1, 2014

Feel free to update the OP with my test results ;-)

GeekEV | April 8, 2014

I've updated the OP with new scores for the v5.9 firmware being rolled out now. The upshot is, it is substantially improved in JavaScript performance, rendering compatibility, web storage and geolocation support.

GeekEV | April 8, 2014

Still no audio/video support though. :-(

Brian H | April 9, 2014

You will wait long and long, for that!

Brian H | August 5, 2014

An FF addon called Download Helper allows audio versions of videos to be saved, IIRC. Haven't yet reinstalled it since being forced off XP to W7.

LetsGoFast | October 24, 2014

This is very helpful. I am building a simple web application to calculate a time estimate to reach a desired level of charge given current level of charge to use at superchargers and I was curious about the user agent and capabilities of the Tesla browser (I don't actually have one yet). Is there by any chance a browser build I could run to simulate the in-car one on a desktop? Does Tesla provide any developer support at all?

Gadfly | October 24, 2014

Is your iPhone browser service free? Complaining about an Internet feature which is completely free seems a bit churlish.

What are all you guys who want lightning fast Internet willing to pay?

Mike83 | October 24, 2014

When I am in Zen mode the browser is very fast. If I am in a hurry it slows down. ;-)

ticobird | December 25, 2014

I'm surprised nobody has mentioned the connection to the internet is through the AT&T 3G network and not the 4G or 4G LTE. This has more to do with speed than the hardware.

Brian H | December 26, 2014

Wider coverage.

mille | December 26, 2014

I think video support should be enabled when the car is not moving. I have this feature in my (soon ex) Audi Allroad DVD player. When the car is moving the sound keeps on playing but the screen goes dark with a message telling me that video will be back when the car will stop. But i think there is a physical sensor somewhere and I don't know if Tesla could do it by software alone

Anyway I think it would be cool to implement this feature already available in ICE cars...

01TECH | January 15, 2015

I have enjoyed this thread. I was thinking how cool it would be to have a Bluetooth keyboard and use the browser & wireless printer to have a mobile office. Now with the executive seating option, it seems more and more possible every day.

Haggy | January 15, 2015

I also had video in a previous car, but only when in park with the parking brake engaged. The obvious problem with the MS is that you still can't pop in a Blu-Ray disc.

The other problem is that the browser causes me to get messages from websites telling me to upgrade my browser because it's no longer a supported version.

richard_lawson | January 15, 2015

The browser is almost useless because many pages just hang up trying to load.

PBEndo | January 15, 2015

Do some graphics intensive browsing over wifi and you will see the bandwidth is not the only thing holding it back.