Background

Name Collision refers to the situation in which a resource name that is intended to be resolved in one naming system is inadvertently resolved in a different naming system, potentially leading to unexpected behavior such as communication being disrupted or redirected from its intended recipient. For additional information and resources related to name collisions, or to see what ICANN is doing to mitigate the risk of name collisions in the New Generic Top-Level Domains (gTLD) Program: 2026 Round, please see the Name Collision webpages on the ICANN website.

The delegation of almost any new gTLD carries some risk of name collision. ICANN has implemented the Name Collision Risk Management Framework, following recommendations from the Name Collision Analysis Project Study Two Report [PDF], as directed by the ICANN Board on 7 September 2024.

Almost all services on today's Internet depend on the Domain Name System (DNS), as usage of services under a domain instigates DNS traffic to that domain. The number of unique networks that send DNS requests hence reflects the overall popularity of the domain's services. This DNS-based metric "DNS Magnitude" can be used for estimating the popularity of a domain. See https://magnitude.research.icann.org/ for more information.

2026 Round | TAMS: Name Collision Observatory

Name Collision Observatory

The Name Collision Observatory (NCO) allows you to display historical magnitude data for up to one year for a string, whether it is an existing top-level domain (TLD) or not. The data is provided by a number of root server operators, as well as by some recursive data providers as displayed in the NCO user interface.

The authoritative (root server) data is aggregated into a single score across participating root server operators. Participating root server operators may change over time. Data from participating recursive name server operators are published as received and is not modified by ICANN. The individual recursive name server datasets might have disparate trend lines for a single TLD string resulting from the DNS queries unique to each operator.

The NCO provides access to datasets related to all strings above a certain threshold of query volume that may help applicants to assess likelihood of their string causing high-risk of name collisions. However, the metrics for an applied-for string are only one of several factors, both quantitative and qualitative in nature, that will be considered when assessing the risk associated with that string in the 2026 Round gTLD application process. Applicants should not assume that if this tool indicates a low volume of queries for a string, the string will be assessed during the application process as safe to be delegated. For more information see the "Name Collision" section of the latest version of the Applicant Guidebook.

User Instructions

Name Collision Observatory Page

On the Name Collision page, you can submit a string and date range. The string must conform to label rules as defined in RFC1035 and RFC5890. The date range can begin as far back as 365 days from the current date and as recent as one day before the current date. Note that some data sources might not have data for the specified string within the specified date range.

Graph

When you specify the string and date range and click Submit, the graph displays the available data for the provided data sources. You can hide and display each data source's graph line by clicking its checkbox in the legend below the graph. If a data source does not have data for the string in the date range, its checkbox will be disabled.

Daily Stats table

The Daily Stats table displays Query Volume and Magnitude Rank in addition to Magnitude Score for each data source that has at least one day of data within the date range for the provided string (any dates without data will be listed with "(no data)" for that row). If a data source does not have data for the string in the date range, its tab on the table will display "No data found", with no table rows displayed.

Click the Download icon to download a CSV file of the Daily Stats results. The file will include data for each data provider as available within the previous 365 days, regardless of dates selected in the Start Date and End Date fields at the top of the page.

Comparative Magnitude Data Page

On the Name Collision page, click the Comparative Stats link to open the Comparative Magnitude page, which displays how the specified string compares to other queried TLD strings by magnitude rank. The link opens a new browser page with magnitude data for a single date. The date, displayed near the top of the page, represents the most recent day that has data from root server operators and at least one recursive data provider.

The specified string is displayed below the date, along with its Magnitude Score and Rank for each available data source. In the All TLD Strings table, the row that contains the specified string is highlighted in yellow. You can click "Show Table Position of…" to jump to the specified string's position in the table.

Support

For support contact globalsupport@icann.org

Disclaimer

Data Provided "As Is"

This data is provided free of charge and on an "as is" basis. ICANN makes no representation or warranty of any kind, express, implied or otherwise, regarding the accuracy, completeness, or suitability of the data for any purpose including without limitation any implied warranty of merchantability, fitness for a particular purpose, or any implied warranty arising from statute, course of dealing, course of performance, or usage of trade. Without limiting the generality of the foregoing neither party has any obligation to indemnify, defend, or hold harmless the other against any claim, suit, or proceeding which arises from use of this data.

No Reliance; Independent Evaluation

You acknowledge and agree that you are not relying, and have not relied, on the data as a basis for any decision, and that you are solely responsible for conducting your own independent evaluation and for all decisions you make. ICANN can remove access to the data at any time.

Name Collision Observatory FAQs

Q1. What is the Name Collision Observatory (NCO) tool?

The NCO is a web-based tool that helps gTLD applicants understand whether a proposed gTLD string may cause high-risk name collisions before they submit an application.

The NCO is available at https://newgtldprogram-nco.icann.org/

Q2. What is the significance of the tool?

Name collisions can cause confusion and produce adverse results. The risk of name collisions is evaluated during the String Evaluation phase of the gTLD application process in the New gTLD Program: 2026 Round. If a string is identified as high-risk, the applicant may be required to develop a mitigation plan, which can add cost, time, and complexity to the application. So, it's helpful to understand early if your string is potentially a high-risk string.

Q3. What does the tool do?

The NCO tool can help you assess the likelihood of a string causing high-risk name collisions by allowing you to better understand how different strings relate to each other from a popularity standpoint. It provides a data-based signal derived from DNS query frequency to help new gTLD applicants understand whether a string might present an elevated likelihood for causing high-risk name collisions. The NCO does not determine whether a string will pass or fail evaluation in the New gTLD Program.

Q4. How is the data for the tool collected?

The NCO aggregates data daily from multiple sources. This includes several root server operators, as well as publicly available data from two recursive DNS resolvers: Cloudflare and QAX.

Q5. Will the string that I search for be logged?

No, the NCO tool does not log nor retain queried strings.

Q6. How do I use the tool?

To use the tool, enter a string (e.g., the string you intend to apply for). Internationalized Domain Name (IDN) strings may be entered directly, or as Punycode (their ASCII equivalent mapping).

The NCO tool will return a DNS Magnitude score from 1 to 10, representing the relative frequency of DNS queries observed for that string, which can then be reviewed.

To compare the string data to other strings, click Comparative Stats.

The Comparative Magnitude Data table displays the DNS Magnitude score and score rank for the most queried TLD strings, whether delegated or not, on a specific date. The date is selected automatically based on data availability for root server operators and at least one recursive data provider.

ICANN published a video related to the Name Collision Observatory to provide information to users about the tool and how it works. The video is embedded to the page above, but can also be viewed here https://www.youtube.com/watch?v=ubAwLfPKk6s.

Q7. How do I interpret the DNS Magnitude score?

The DNS Magnitude score scales from 1 to 10 and represents the relative frequency of DNS queries observed for that string. The higher the score, the higher the likelihood that the string may cause high-risk name collisions. The DNS Magnitude score should not be interpreted as an absolute risk rating though. Potential applicants should not rely on the NCO alone, and are encouraged to conduct independent research as part of their overall application preparation. The Name Collision Temporary Delegation and the Initial Assessment of Applied for Strings will ultimately inform which strings are deemed high-risk in the New gTLD Program: 2026 Round.

Please also note, you should avoid cross-source comparisons. Scores from one source are only comparable with data from the same source, because the data contexts are not equivalent.