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Internet Domain Name Index

  • IDNX is the leading price index for the domain market, calculated from more than 225,000 real sales
  • It is the appropriate benchmark for estimating changes in the value of your domains
  • IDNX is featured at financial data platforms Bloomberg and Thomson Reuters

Run your own analysis: customize the graph

IDNX is available on Bloomberg and Reuters under IDNX <Index> and .IDNX, respectively.

April 4, 2016

BlogRandom ramblings about startup name(s)

My brother Wieland got heavily involved in a new startup dubbed “jobMapp”, which is trying to establish a new market place for every-day jobs in Spain. All fraternal affection aside, I am really excited about the project.  I think it is cool to see how easy it is to e. g. arrange for the delivery of documents and small parcels in Madrid through a dedicated website (not sure I would hire somebody to to my household chores, t. b. h.).

At the same time, I am less convinced that jobMapp is really a great name to develop into a strong brand. I have been told the name several times by now and I still find it hard to remember.  Why not go for a more intuitive name? What can be more important for a start up than carefully selecting a catchy, short, pronounceable and, most importantly, distinctive name?

(Don’t worry, Wieland, if this sounds overly critical – I am just an academic commenting from the sidelines. You guys will prove me wrong,  for sure.)

December 23, 2014

BlogWinston Churchill. On Domains?

“Audiences display an uniform preference for short, homely words of common usage”.

The Scaffolding of Rhetoric (1897)

December 10, 2014

BlogDomain prices in October and November: Up up up – and a little down.

October witnessed a strong upswing in domain values with sales closing at 4.4% higher prices than in the month before. November did reverse this trend a little with prices falling -0.7% lower again. In the last 12 months, domains gained 25% in value.

August 7, 2014

BlogInteresting read: “A Hybrid CBR-ANN Approach to the Appraisal of Internet Domain Names”

New paper by Sebastian Dieterle and Prof. Dr. Ralph Bergmann

Good domain names have become rare and trading with premium domain names has developed into a profitable business. Domain appraisals are required for many different reasons, e.g., in connection with a loan on a domain name. The aim of this paper is to analyze various methods for estimating prices for domain names. The criteria for this are predictive accuracy, traceability and speed of the appraisal. First, the scientific relevance of the topic is demonstrated based on intensive literature and Internet research. Several approaches based on artificial neural networks (ANNs) and case-based reasoning (CBR) are developed for estimating domain name prices. In addition, hybrid appraisal approaches are introduced that are built up on CBR and which use ANN for improved adaptation and similarity determination. The approaches are evaluated in several con gurations using a training set of 4,231 actual domain transactions, which demonstrates their high usefulness.

May 12, 2014

BlogResale prices for Internet domain names climb to new peak in April

The new estimates for the Internet Domain Name Index (IDNX) suggest a price increase of 1% in April. The return in the last 12 months was 17%. This robust growths clearly puts an end to the 2011-2012 years of stagnating as prices reach a new record high. The upward trend is evidence that values for “traditional” Top Level Domains (TLD) are not diluted (at least at a large scale) by the launch of new TLDs.

February 13, 2014

Blog2013: A solid year for domain values

In 2013, domain news were dominated by one single topic: the launch of new global top level domains and the massive supply of new domains. When looking at the sales data, one could describe the industry’s response to the changing environment as: “Keep calm and trade on.”

Despite all uncertainties and buzz created around the brave new domain world, developers and investors did not walk away from the established domains (COM/NET/ORG/… and ccTLDs). On the contrary, resale prices for traditional domains rose by overall 12% in 2013.

Obviously, we can only guess whether the return on domains could have been even higher without the looming competition from new TLDs. 2013 was a strong year for the IT industry. Internet giant Twitter went public and the stock price index NASDAQ 100 went up by 29%. Against this benchmark, domain performance can be described as solid, but not stellar.

December 13, 2013

BlogDomain prices continue upward trend of last 4 months

The second half of 2013 witnessed a strong overall upward trend in Internet domain name prices. The recent IDNX update for prices of domains sold in November is 7.7% above October’s values (which has been a weak month, though). The month-to-month fluctuations are interesting, still a more long term perspective might be more relevant: Overall, … Continue reading “Domain prices continue upward trend of last 4 months”

December 6, 2013

BlogInfographic on Index Estimation

Courtesy of MIT Center for Real Estate.

November 25, 2013

BlogUP, UP, DOWN: Prices for domains cannot keep pace in October.

Prices paid for domain names decreased by 3% during October. The last IDNX update indicates that domain markets could not keep the momentum of the previous 2 months when re-sale prices increased by more than 9%. Given the strong performance of technology related market indicators like the NASDAQ100 stock price index in the last months, … Continue reading “UP, UP, DOWN: Prices for domains cannot keep pace in October.”

July 11, 2013

BlogPrices for domains up 2 % in June

The new estimates for the Internet Domain Name Index (IDNX) show a 2 percent increase in re-sale prices for domain names. The number of transactions is also stronger than in the previous month, suggesting that domainers were not only able to sell at higher prices but also in larger quantities.

Core resultDomain prices are as real as stock prices

Domain prices have an economic foundation. They are not detached from the economy in general. On the contrary, domain price changes are very similar to changes in the NASDAQ 100 index, the stock prices of internet giant Google or total revenues from online marketing (US). The strong correlation shows that domain name buyers and sellers make economically motivated price decisions. Domain markets are not a cloud-cuckoo-land where dreamers trade esoteric goods at imaginary prices.

For further analysis, the index estimates can be downloaded here.

Read full study: "Valuable Words: The Price Dynamics of Internet Domain Names"

whyWhat is a domain name index good for?

The internet domain name index IDNX brings more transparency to domain markets. It provides a reliable benchmark for domain name traders and investors looking for information on price trends, returns and fundamental risk of internet domain names.

IDNX helps domain owners to track the value of their domains in time.

Furthermore, it can serve as a fever curve for the internet economy in general, covering small enterprises as well that are currently excluded by stock-price based indices, which by definition focus on the large corporations only.

Prof. David Geltner, Director of Research, MIT Center of Real Estate

“Lindenthal’s domain name index is on a very exciting frontier: that of virtual space. Just as the physical 2-dimensional (or 3-dimensional) real surface of the earth was the arena for mankind's progress until now, and the development of markets to trade ownership of that space separated civilized and modern man from his more barbaric ancestors, virtual space will allow mankind to grow and flower in this new millennium. In this frontier it is vital that we have good metrics, and Lindenthal's domain name index is computed in an econometrically rigorous manner as pioneered in the real estate investment industry. I am very pleased to see this development.”

- Prof. David Geltner, Director of Research, MIT Center for Real Estate

Tim Schumacher, Founder

“We at believe that Thies’ excellent work on domain pricing is extremely important in order to establish a professional domain name market in the long run. Only a market where fair and transparent prices exist can be liquid and efficient. The domain market is on a good way towards that, and any Domainer who uses Thies’ insights and ancillary domain pricing tools to set fair and fixed prices on his or her domain names, helps to make our industry more professional and will sell more domain names.”

- Tim Schumacher, Founder

An index brings transparency to domain markets.

howHow is the index estimated?

IDNX is a constant quality price index that takes into account the huge variety in domain names. The quality of the domain names is controlled for by empirical estimation techniques called hedonic regression and hedonic repeat sales regression. The empirical work is based on more than 260,000 real domain transactions from, the largest domain market place, spanning the years 2005-2013.

Why is it essential to consider the quality of domains when estimating an index? Taking the average of transaction prices gives a first indication of price developments but does not control for quality differences in the domains sold. If there is a time period in which more high-quality domains are sold, the average transaction price will increase, regardless of any true trend in prices. Putting it differently, one is comparing apples to oranges.

Two general methodologies are commonly used to price non-standardized assets like real estate or art. The first one, the so-called hedonic regression analysis, explains the price of an asset by a set of quality variables that describe the characteristics (hedonics) of that asset. Alternatively, the repeat sales methodology traces individual domains in time, comparing each transaction to previous transactions of the very same asset. While this is probably the most direct form of making sure to "compare apples to apples," it is disregarding all information on transactions that are sold only once. IDNX combines the advantages of both methodologies and relies on a so-called Hedonic Repeat Sales methodology, using a hedonic classification of the TLD and otherwise a repeat sales approach.

The Repeat Sales Index Estimation

A full discussion of the method and the data can be found in the accompanying paper.

IDNX is based on a large sample of real domain transactions.

The empirics account for differences in the quality of sold domains.

Read full paper here.

tldRanking of Top Level Domains, measured

The market's relative ranking of Top Level Domains (TLD) is obtained as a by-product of the index calculation. The empirics confirm a domain trader's mantra: .COM is the most valuable TLD, followed by .DE, .CO.UK, .NET, .EU, .ES, .ORG, .INFO, .BIZ, and .MOBI.

The table below shows pairwise price differences (in percent) for identical SLDs under the 10 most frequently traded TLDs. NET domains trade for 75 percent less than COM domains (for identical SLDs), the discount for ORG is 84 percent, INFO, MOBI or BIZ trade for less than a tenth of COM.

In the current econometric setup, the TLD differences are assumed to be constant in time. Furthermore, the language of the SLD is not considered. This might lead to lower estimated discounts for ccTLDs from non-English speaking countries vs. COM whenever the SLD carries some meaning in the local language.

For more results, check out the paper.

TLD pecking order: COM > DE > CO.UK > NET > EU > ORG > ES > INFO > BIZ > MOBI


  • How often is IDNX updated?
  • New index figures are released on a monthly basis. Follow IDNX on twitter and hear about any updates first.
  • Is IDNX a Sedo initiative?
  • No, IDNX is independent from any party in the domain industry. Sedo has been extremely helpful, though, by granting access to their data. I would be very happy to work together with other domain market places, registrars and researchers as well.
  • Will IDNX share any transaction data?
  • No, sorry. I had to promise to respect the privacy of the parties involved.
  • Is it OK to quote the index?
  • Yes, of course. It would be nice, however, if you included a link to whenever you use the index.
  • Is there an easy way to include the index graphs on other websites?
  • Yes, just copy and paste the code below. All monthly updates will directly display on your site. This code is still pretty experimental. Use at own risk.
    <!--load libraries (in case not already loaded) -->
    <script src=""></script>
    <script src="" type="text/javascript"></script>
    <script src="" type="text/javascript"></script>
    <!--load IDNX -->
    <script src="" type="text/javascript"></script>
    <script type="text/javascript">
             _idnxDisplayGraph('g1',['IDNX','NASDAQ 100'],true);
    <noscript>Please enable JavaScript.</noscript>	
    <!--adjust css, if needed -->
    <link rel="stylesheet" href="" />	
    <link rel="stylesheet" href="" />
  • Can individual domains be priced based on IDNX?
  • Yes and no. Automatic domain appraisals are currently not precise and reliable enough to be of much help when pricing single domains. IDNX, however, shows the general market trend, which is the best estimate for changes in value of single domains (e.g. price changes since the last sale of the domain).
  • Which TLDs are included? Will there be subindices for single TLDs?
  • IDNX is based on transactions from more than 100 TLDs. It is therefore a true global market index. For the most popular TLDs like .COM, .NET or .DE, separate sub-indices are estimated.
  • Does a hedonic regression have anything to do with hedonism?
  • No, unfortunately not.


Thies Lindenthal

Hi, I am Thies Lindenthal.

IDNX is my newest project, linking two of my dearest intellectual play-grounds. I am an University Lecturer at the University of Cambridge and I have been an internet entrepreneur since 1999.

You can contact me at

More research projects of mine can be found at my homepage.

Also, check out the news aggregator that I founded in 1999.

newsIDNX in the Media

Selected articles covering IDNX