Last week, Google claimed Chrome was the most popular web browser in the world. By some measures that’s true, but one leading research site still places it in the No. 3 spot, behind Internet Explorer and Firefox.

That’s about to change.

Net Applications pegs Chrome‘s market share at 19.08%, less than a percentage point behind Mozilla Firefox, which has 20.06%. However, Chrome’s chunk of the market has increased almost 5% over the past year, while Firefox’s has decreased almost 3%. Both, however, are far behind IE, which has a commanding 54.02% of the market.

If trends continue, Google’s browser will soon claim the second spot in the browser wars. So why did Google say it was the world’s top browser?

Google was basing its claim on different data. While Net Applications looks at unique users to determine market share, another research service, StatCounter, looks at overall traffic on 3 million sites.

Which numbers are more valid? It depends. Net Applications ostensibly measures the number of machines a particular browser is installed on, so it’s a good measure of penetration. However, since StatCounter goes by traffic, it’s probably a better measure of popularity. If you do the majority of your surfing on Chrome — only launching IE once in a while for a particular app — you count as exactly one user for both browsers for Net Applications, but your Chrome usage has much more weight for StatCounter.

For both services, the stats only pertain to desktop browsers. On mobile, Safari is king, according to Net Applications, thanks to the large market share of the iPhone and iPad. However, StatCounter shows a three-way race for the top spot on mobile, between Safari, Opera and the Android Browser.

It’ll be interesting to see how Google’s launch of Chrome for iOS will affect the browser race. Since launching last week, Chrome has been the No. 1 free download in the App Store, both for iPhone and iPad. Also, with the release of Android 4.1 “Jelly Bean,” Google is moving toward making Chrome the standard browser on Android devices, too.

What do you think of Chrome’s ascendance as a dominant browser on both desktop and mobile? And which statistics do you trust more? Sound off in the comments.

BONUS: Chrome for iOS Overview

Hands-On With Chrome for iOS

Chrome for iOS is Here

Chrome for iOS is here. Available for the IPhone and iPad, how does it compare to the third-party browser competition?
Sign In

You can sign-in to Chrome for iOS with your Google user name and password. This allows users to sync bookmarks, view open tabs from other devices, access passwords and automatically login to Google services.
Take a Tour

The first time you launch Chrome for iOS, the app offers a user tour.
Search Omnibox

The search and location bar are on in Chrome for iOS, just like with Chrome on the desktop.
Tab Switching

Tab switching works by dragging at the edges. It is card-like, similar to webOS and Android 4.0 Ice Cream Sandwich.
Browsing in Portrait

The number of open tabs is displayed at the top, next to the Omnibox.
Browsing in Landscape

Landscape browsing offers minimal cruft.
Tab View

Tabs can be browsed like cards and quickly removed with a swipe to the left.
Context Menu

The menu button brings up options, including quick access to favorites, email, “Find on Page” and the ability to view tabs on other devices.
Open Tab Sync

You can select open tabs for any of the computers currently logged into Chrome on the desktop or for mobile with open tab syncing turned on. Tapping on a tab will open the window in Chrome for iOS.
Blank New Tab Screen

After closing all tabs, this subtle background greets users.
Chrome on the iPad

On the iPad, Chrome looks much more similar to its interface on a Mac or PC.
Tabs On Top

Chrome’s famous “tabs on top” motif carries over to Chrome on the iPad.
Context Menu

The context menu in Chrome for iPad has more room to breath and expand, thanks to the larger screen.
Browsing Open Tabs

It’s easy to browse open tabs from other synced devices. Here, you can see I am browsing open tabs on my MacBook Air and my iPhone 4S.
Chrome Keyboard

Chrome offers a custom keyboard for search and address entry with the Omnibox.
Chrome for iPad in Portrait

This is how Chrome looks on an iPad while in portrait orientation.
Mobile Safari in Portrait

This is how Safari looks on the iPad. Please note, this iPad is running iOS 6.