MSN Search engine: how it became Bing

By Bill Hartzer · Updated 27 October 2026

What MSN Search was, and what it became

MSN Search no longer exists under any of its names. It was Microsoft's web search service from 1998 until June 2009, when it was replaced by Bing, fully deployed worldwide on 3 June 2009. As of 27 October 2026, the old address search.msn.com returns an HTTP 302 redirect (a temporary forwarding instruction) to bing.com. Anyone typing "MSN search engine" today is, in practice, using Bing.

The verdict on this page is no longer available, but it needs a qualification, because MSN Search had two quite different lives:

1998 to early 2005: MSN Search did not have its own index. It re-served results licensed from other companies, chiefly Inktomi's crawler-based index and LookSmart's human-edited directory.
1 February 2005 to June 2009: it ran on "the first-ever search engine built from the ground up by Microsoft Corp.," with Microsoft's own crawler and index. That engine was renamed twice and became Bing.

The brand was retired; the technology was not. Bing's index descends directly from the one Microsoft built for MSN Search, which makes this the clearest case in search history of a major buyer of syndicated results deciding to build its own.

The names, in order

Microsoft renamed its search service three times in under three years, and the sequence causes most of the confusion about it.

Microsoft's web search service, 1998 to 2009
Name	Period	Where results came from
MSN Search	1998 to January 2005	Licensed: Inktomi, LookSmart and others
MSN Search (new engine)	Beta 11 November 2004; launched 1 February 2005	Microsoft's own crawler and index
Windows Live Search	Public beta reported March 2006; out of beta 11 September 2006	Microsoft's own index
Live Search	Rebrand reported March 2007	Microsoft's own index
Bing	Announced 28 May 2009; fully deployed 3 June 2009	Microsoft's own index

Some of those dates are firmer than others. The 1 February 2005 launch, the 11 September 2006 exit from beta and the 2009 Bing dates come from Microsoft's own press releases. The exact 1998 launch day, the 8 March 2006 Windows Live Search beta and the 21 March 2007 rename to Live Search are recorded by Wikipedia but have not been confirmed against a Microsoft primary source.

1998 to 2004: a buyer of other companies' results

For its first six-plus years MSN Search was a branded front end. Microsoft supplied the page and the audience; other companies supplied the results. The primary evidence for this comes from the suppliers' own securities filings, which is unusual and useful: they had to disclose how much they depended on Microsoft.

Inktomi. Inktomi's IPO registration statement, filed 16 April 1998, says it "has entered into contracts to provide services based on its Internet search engine to Microsoft Corporation," and that for the six months ended 31 March 1998, "Wired, NTT and Microsoft accounted for 59%, 6% and 20% of total revenues, respectively." The prospectus refers to the Microsoft property as "Microsoft Start, once launched." Inktomi's scale a few years later is recorded by its co-founder Eric Brewer, who described the engine in 2001 as running on more than 1,000 nodes of two-CPU Sun workstations and serving more than 80 million queries a day. Those are circa-2001 figures for Inktomi across all its customers, not MSN alone, and Inktomi was acquired by Yahoo in 2003.

LookSmart. LookSmart's IPO registration statement of 14 June 1999 names "The Microsoft Network (MSN)" first among its distribution partners. The same filing says more than 43 million people used looksmart.com and its partners' sites in April 1999; that is reach through syndication across all partners combined, not visitors to LookSmart itself. By 2003 the dependence was extreme. LookSmart's annual report for that year states that "Microsoft's MSN accounted for 68% of our revenues in 2003" (68 percent of total revenues; the filing separately gives 64 percent of listings revenues).

Wikipedia also records LookSmart results blended in early 1999 and AltaVista used briefly in 1999, and paid listings in this era came from Overture. The first two points have not been confirmed from a primary source. There is no evidence that MSN Search ever used Google.

2004 to 2005: Microsoft builds its own index

The switch is bracketed by two sworn sentences in Microsoft's annual reports. The fiscal 2004 report (year ended 30 June 2004) says: "We are building our own algorithmic search engine and investing to support the continued growth of our advertising business." The fiscal 2005 report says: "We have built our own algorithmic search engine to provide end users with more relevant search results." The same 2005 filing says MSN Web sites were "visited by more than 420 million unique users every month"; that is reach across the whole MSN network, not a count of search users, and neither filing gives an index size or a query count.

The supplier relationships ended on the same timeline. In October 2003, LookSmart reported, "we were informed by Microsoft that it would not renew the distribution and licensing agreement," and "the licensing portion of our agreement with Microsoft expired on January 15, 2004." Microsoft stopped buying months before it was ready to launch.

The beta of the new engine appeared on 11 November 2004 with an index Microsoft described as "about 5 billion Web documents," as reported by Redmond Magazine. The full launch on 1 February 2005 covered 25 markets and 10 languages, with "More than 1.5 million answers from Microsoft Encarta" shown inline and a "Near Me" local search feature, according to Microsoft's launch release, which gave no index size.

Windows Live Search, Live Search, and the move to Bing

On 11 September 2006 Microsoft took Live Search and Live.com out of beta in 47 markets and said "Live Search will now power the Web search capability on MSN." At the time MSN claimed "more than 465 million unique users worldwide per month," again a network figure rather than a search figure. On 26 September 2007 Microsoft released an updated Live Search with an "Over fourfold increase in index size" and greater use of "user click-stream data" (records of what searchers clicked) in ranking. It did not say fourfold of what absolute number.

On 28 May 2009 Microsoft announced Bing as a "Decision Engine," rolling out "over the coming days" and "fully deployed worldwide on Wednesday, June 3." The announcement cited a comScore figure that "as many as 30 percent of searches are abandoned without a satisfactory result"; that is a statistic Microsoft chose to support its pitch, not an independent finding about Live Search. The release does not mention Live Search by name.

The business model did not change through any of this: search advertising on Microsoft's pages, first through a third-party paid-listings supplier and later through Microsoft's own advertising platform. MSN Search was never reported as a separate revenue line; it sat inside Microsoft's MSN segment, so no MSN Search-specific revenue or query figure exists in the filings.

What MSN Search was bad at, and why it matters now

As a reference point, MSN Search shows the two weaknesses of a resold-results service with unusual clarity. Before 2005 its results were only as good as Inktomi's and LookSmart's, and Microsoft could not improve them except by changing supplier. Its supply was also contractual: when Microsoft wanted control, it had to end agreements and spend years building a replacement. Once Microsoft did own its engine, it carried three names between 2005 and 2009 and never kept one for as long as three years, so the brand most people remember, MSN Search, belongs mostly to the period when the results were not Microsoft's.

For the suppliers the lesson ran the other way. LookSmart drew 68 percent of its 2003 revenue from one buyer and lost it in a single non-renewal. Much of the early-2000s results-syndication business rested on a handful of portal customers.

Common misconceptions

"Bing was Microsoft's first search engine." Microsoft's own index dates to the November 2004 beta and the February 2005 relaunch of MSN Search. Bing was a rename and expansion of that engine, not a new start.

"MSN Search was always Microsoft technology." From 1998 to 2004 it re-served Inktomi, LookSmart and other suppliers' results. Microsoft's own 2004 annual report described its engine as still being built.

"MSN Search used Google." No source supports this.

"MSN Search still exists." As of 27 October 2026, search.msn.com redirects to Bing. LookSmart's account of losing Microsoft is in its 2003 annual report.

Frequently asked questions

Does MSN Search still exist?

No. MSN Search was renamed Windows Live Search in 2006 and Live Search in 2007, then replaced by Bing, which was fully deployed worldwide on 3 June 2009. As of 27 October 2026, the old address search.msn.com redirects to bing.com, so a search started from MSN today runs on Bing.

Is MSN Search the same as Bing?

Bing is the direct successor. From 1 February 2005 MSN Search ran on an engine and index Microsoft built itself, and that engine was renamed twice and became Bing in June 2009. Before 2005, though, MSN Search was a different thing: a front end for results licensed from Inktomi, LookSmart and others.

What search engine did MSN use before Bing?

From 1998 to early 2005, MSN Search re-served licensed results, chiefly Inktomi's crawler-based index and LookSmart's human-edited directory. Inktomi's 1998 prospectus records Microsoft as 20 percent of its revenue. From February 2005 MSN used Microsoft's own engine, later called Windows Live Search and Live Search, which became Bing in 2009.

When did Microsoft build its own search engine?

Microsoft's fiscal 2004 annual report said it was "building our own algorithmic search engine"; the fiscal 2005 report said it "built" one. The beta appeared on 11 November 2004 with an index of about 5 billion documents, and MSN Search relaunched on it on 1 February 2005, in 25 markets and 10 languages.

What was Live Search?

Live Search was the name of Microsoft's own search engine between MSN Search and Bing. It left beta as Windows Live Search on 11 September 2006 in 47 markets and took over MSN's web search; Wikipedia dates the shortening to Live Search to March 2007. In September 2007 Microsoft reported a fourfold index increase. Bing replaced it in June 2009.

Did MSN Search use Google results?

No source supports that. Before 2005 MSN Search licensed results from Inktomi and LookSmart, with paid listings from Overture, and from February 2005 it used Microsoft's own index. Google powered other portals in that era, notably AOL from 2002, which may be the source of the confusion.

MSN Search