Global Terrorism Database

Information on more than 200,000 Terrorist Attacks
Access the GTD

What is the GTD?

The Global Terrorism Database (GTD)™ is the most comprehensive unclassified database of terrorist attacks in the world. The National Consortium for the Study of Terrorism and Responses to Terrorism (START) makes the GTD available via this site in an effort to improve understanding of terrorist violence, so that it can be more readily studied and defeated. The GTD is produced by a dedicated team of researchers and technical staff.

The GTD is an open-source database, which provides information on domestic and international terrorist attacks around the world since 1970, and now includes more than 200,000 events. For each event, a wide range of information is available, including the date and location of the incident, the weapons used, nature of the target, the number of casualties, and – when identifiable – the group or individual responsible.

Defining Terrorism

The GTD defines terrorism as:

“The threatened or actual use of illegal force and violence by a non-state actor to attain a political, economic, religious, or social goal through fear, coercion, or intimidation.”

The data collection team uses a series of inclusion criteria to systematically identify events for inclusion in the database. More information about the data collection process can be found in the GTD Codebook.


Accessing the GTD

How can I access the GTD?

There are three ways in which you can access the GTD depending on the type of user you are:

Commercial/Organizational Clients: Clients wanting to access the GTD for commercial or organizational purposes can do so through our exclusive commercial distribution partner CHC Global, specifically through their Global Terrorism Insights Platform (GTIP). The GTI Platform allows clients to purchase the data in a modular format to suit their individual organization’s requirements.

Individual Academic Users: Clients wanting to use the GTD for their own personal academic purposes can access the data through this website here subject to agreeing to our End User Agreement.

Government Users: Individuals from certain US, UK and German government bodies can access the GTD data through this website here, subject to agreeing to our End User Agreement.

Who are CHC Global and why does START partner with them?

CHC Global is an independent firm of strategic malicious risk advisors who have been our exclusive commercial distribution partner since 2019. They work with public and private sector organizations across the globe, helping their clients solve complex malicious risk problems. CHC’s impressive team has expertise in delivering terrorism analytics and importantly they share our commitment to distributing the GTD widely to those who work to understand and combat terrorism.

What is the Global Terrorism Insights Platform?

The Global Terrorism Insights Platform is a secure cloud-based terrorism intelligence system, created exclusively by CHC Global in conjunction with us here at START.

The platform brings together the Global Terrorism Database with world-leading insights curated by CHC Global’s team of experts. The sophisticated software behind the GTI Platform has been transformative in how the data is presented and can be interpreted and utilized. Additionally, through offering the GTD to clients in a modular format there are a range of options and price brackets to suit a wider range of budgets.

Additional Information for individual/academic users

Can you provide further clarity on how you define an individual user?

Individual users are those who intend to use data for non-commercial, personal academic purposes. Some examples of individual users would be:

  • A student, attending or affiliated to a specific university, using the data for analysis or research.
  • A professor or academic using the data for their own work.

For all individual users, the condition for free access is the appropriate citation of the data and attribution to START.

Can I use the GTD for my research/analysis/project?

Yes, we encourage researchers, analysts, and scholars to use the GTD in their work. Users can download the dataset by following the links on the “Access the GTD” page.  All individual users can also search and browse the database as long as they accept the individual terms of use.

You will be required to accept the End User Agreement. It is vital that you cite the GTD appropriately, acknowledge any changes you make to the GTD in your analysis, and carefully read the End User Agreement as there are important restrictions to ensure that the data are only used for the purpose of better understanding, or combating terrorism.

 How should I properly cite the Global Terrorism Database?

 Our recommended citation for the database is:

National Consortium for the Study of Terrorism and Responses to Terrorism (START), University of Maryland. (2019). The Global Terrorism Database (GTD) [Data file]. Retrieved from


Additional Information for Government users

How can US Government employees and contractors download the GTD?

Individuals from certain US, UK and German government bodies can access the GTD data through this website here, subject to agreeing to our End User Agreement.

How can US Government employees download the legacy GTD data?

Currently, United States Federal Government users have "Government Purpose" rights to the portions of the data funded by the US Government. To access this funded legacy data up to and including the 2019 data, (which excludes updates/revisions) US Government users can fill out the brief form to request access here . Our distribution partner, CHC Global will confirm access. Non-government organizations interested in using the GTD for USG purposes can no longer request access through their US Government client. Non-government organizations interested in using the GTD should select "Organizational Use," and fill out the brief form to request access. CHC Global will respond with additional information about licensing and fees

How can US Government employees download the most recent GTD data?

US Government users can fill out the brief form to request access here. Our distribution partner, CHC Global will respond with additional information about licensing.

About the GTD

Why is the GTD widely considered to be the most comprehensive terrorism events database in the world?

The methodological rigour and academic pedigree underpinning the GTD is unmatched, and the GTD team comprises both data and terrorism experts. Each entry to the database has undergone a detailed process of coding and checking against inclusion criteria, and can have up to 136 datapoints associated with it. The GTD is most cited source globally in terrorism studies. In addition, START is a trusted partner for the US, UK, and German governments on asymmetric threats.

Why is there a time lag in releasing updates to the GTD?

Due to our rigorous processes of collection, coding, and quality assurance, all of which involve the input of expert members of the team, the release of GTD data is not as close to present day as other terrorism databases However it is our prioritisation of accuracy over speed that sets the GTD apart from other databases.

When fully funded, GTD source document collection occurs daily; however, systematic curation of structured data requires considerable time and effort on the part of the research team. The database is typically updated annually for non-commercial users. Commercial users may have access to preliminary data updates on a more frequent basis. The GTD is produced with the intent of providing a long-term view of terrorism and as such, we prioritize accuracy and completeness.


Why are the data for 1993 missing?

The original PGIS data, upon which the 1970-1997 GTD data are based, consisted of hard-copy index cards, which were subsequently coded electronically by START researchers. Unfortunately, the set of cards for 1993 was lost prior to PGIS handing the data over to START. Country-level statistics for 1993, including number of incidents, number of fatalities, number injured, number of U.S. fatalities, and number of U.S. injured were recovered from a PGIS Risk Assessment Report for 1993. These figures are available in the appendix of the GTD Codebook.

Why doesn't GTD have a single definition of terrorism?

In the absence of a universally accepted definition of terrorism, the GTD uses several coded criteria to cover key characteristics of terrorism through a combination of inclusiveness and filtering. The goal is to have a dataset that is useful to as many interested users as possible.

While the GTD inclusion criteria offer a comprehensive definition of terrorism, we encourage users to take advantage of the GTD's flexibility to restrict the data according to their definitional preferences. This includes filtering search results based on whether the coder noted some uncertainty whether an incident meets the criteria for inclusion ("Doubt Terrorism Proper," systematically available for post-1997 cases only). Also, users can filter search results based on which of the following three criteria are met (available for all cases):

Criterion 1: The act must be aimed at attaining a political, economic, religious, or social goal.
Criterion 2: There must be evidence of an intention to coerce, intimidate, or convey some other message to a larger audience (or audiences) than the immediate victims.
Criterion 3: The action must be outside the context of legitimate warfare activities, insofar as it targets non-combatants

Please see our GTD Codebook for more details.

I think I may have found an error in the database. What should I do?

While every effort is made for each incident to corroborate facts from multiple independent sources and to eliminate errors through a systematic review process, the magnitude of the database (more than 200,000 discrete incidents) means that occasionally an error will evade detection and appear in the database or a valid incident will not be recorded. In these cases, we rely on users who become aware of such an error to contact us and let us know so we can review the case and make any appropriate corrections.

Does the GTD include foiled and failed plots or threats to attack?

Although the GTD does include failed attacks, it does not include foiled or failed plots, the distinction being that the attack must actually be attempted to qualify for inclusion in the database. Likewise, the GTD does include attacks in which violence is threatened as a means of coercion, but does not include threats to attack where no action is taken.

Does the GTD include insurgency?

To some degree, the GTD does include acts that occur either during a specific insurgency or that closely resemble an insurgent attack against a military target. Without clear definitions of terrorism and insurgency in the literature these types of actions can overlap, with insurgent organizations using violence against non-combatants alongside attacks directed at combatants. While terrorism as a tactic has been used within a number of insurgent campaigns, the GTD should not be viewed as a comprehensive collection of insurgent attacks.

Does the GTD include incidents of state terrorism?

No, the GTD is limited to acts of non-state terrorism. One of the three necessary criteria for inclusion is that there must be sub-national perpetrators. The database does not exclude cases in which states sponsor attacks by non-state actors that otherwise meet the inclusion criteria. If it is unclear if an attack was carried out by state actors, the event may be included in the database and marked as “Doubt Terrorism Proper: State Actor.”

Please see our GTD Codebook for more details.

Who makes the decisions about what to include as an incident?

The basic criteria were formulated by the GTD Advisory Board, and are documented in the GTD Codebook. In practice, trained researchers decide whether a case they are working on fulfills these criteria, and this decision is reviewed by GTD supervisory staff. In cases where determination is difficult, the case is raised for review and deliberation among the full data collection team.

Is there a methodological reason for the decline in the data between 1997 and 1998, and the increases since 2008 and 2012?

While efforts have been made to assure the continuity of the data from 1970 to the present, users should keep in mind that the data collection was done as events occurred up to 1997, retrospectively between 1998 and 2007, and again concurrently with the events after 2008. This distinction is important because some media sources have since become unavailable, hampering efforts to collect a complete census of terrorist attacks between 1998 and 2007. Moreover, since moving the ongoing collection of the GTD to the University of Maryland in the Spring of 2012, START staff have made significant improvements to the methodology that is used to compile the database. These changes, which are described both in the GTD Codebook and in this START Discussion Point on The Benefits and Drawbacks of Methodological Advancements in Data Collection and Coding: Insights from the Global Terrorism Database (GTD), have improved the comprehensiveness of the database. Thus, users should note that differences in levels of attacks before and after January 1, 1998, before and after April 1, 2008, and before and after January 1, 2012 may be at least partially explained by differences in data collection; and researchers should adjust for these differences when modeling the data. 

In general, trends over time should be interpreted with caution due to the possible effects of changing availability of reliable source materials. Likewise, the GTD is not directly comparable to other sources of data on terrorism, as differences in definitions, sources, and workflows will produce misleading inferences.

I need to provide raw GTD data for an academic journal replication archive. Do I need permission?

Yes. The Terms of Use for the GTD specifically prohibit the republication of the GTD data in any manner on any publicly-available website. This includes journal replication archives and institute / research center websites, among others. If an academic publication requires the posting of GTD data in the replication archive, please contact GTD staff to obtain permission to post the GTD data.

Can the GTD be used as a source of information on legal dispositions of criminal charges?

No. Statistical information contained in the Global Terrorism Database is based on reports from a variety of open media sources. Information is not added to the GTD unless and until we have determined the sources are credible. Users should not infer any additional actions or results beyond what is presented in a GTD entry and specifically, users should not infer an individual associated with a particular incident was tried and convicted of terrorism or any other criminal offense. If new documentation about an event becomes available, an entry may be modified, as necessary and appropriate.

Who funds collection of the data?

The collection of the GTD is currently funded by the US Federal government, the German Federal Foreign Office (FFO) and the United Kingdom Foreign, Commonwealth, and Development Office (FCDO).

 START is actively considering funding solutions to continue to maintain and improve the GTD.

 All decisions about GTD data collection are made independently by the research team. The GTD does not represent the official position of any funding agency.

Does the GTD include the RAND database and/or the WITS database?

The RAND Database of Worldwide Terrorism Incidents (RDWTI) and the Worldwide Incident Tracking System (WITS) compiled by the National Counterterrorism Center (NCTC) are two important data collection efforts that coincided with the collection of the GTD for several years. These data collection efforts were conducted by RAND and NCTC independently of START’s GTD collection effort, with their own definitions, inclusion practices, and source requirements. The GTD does not systematically include records from either RDWTI or WITS. On a very limited basis, the GTD may reference other databases or chronologies among the sources of information for individual cases. The RDWTI and the WITS databases were never used as the only sources for an event’s inclusion in the GTD and neither of these databases were comprehensively incorporated into the GTD. All primary and supplemental data collection efforts that comprise the GTD are listed in the GTD Codebook. Supplemental data collection efforts are subject to the same GTD definitional criteria and inclusion practices as the primary data collection process.

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We welcome questions and feedback from users.

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National Consortium for the Study of Terrorism and Responses to Terrorism
An Emeritus Center of Excellence of the U.S. Department of Homeland Security