Overton Index

Overton Index is the world’s largest policy and grey literature database, tracking over 21 million documents and automatically finding links to the evidence they reference.

Use the full-text search and policy-to-policy citations to see how research influence spreads through policy organisations and get an accurate picture of impact.

You can use Overton Index to:

• track and analyse evidence use in policy
• access policy documents for analysis
• support reporting and research assessment for annual reports, grant applications, tenure applications and evaluations.

Licence information

Authorised users are not permitted to use Overton (in whole or in part) other than for Educational purposes. Educational purposes are defined as education, teaching, tuition, training, instruction, learning, private study and/or research, including distance learning and teaching.

Authorised users are not permitted to make any Commercial use of Overton (in whole or in part). Commercial use means use for the purpose of earning monetary reward or generating profit (whether by or for the Institution or an Authorised User) by means of the sale, resale, loan, transfer, licence, hire or other form of exploitation of the licensed material, but, for the avoidance of doubt, excluding: use for which the Institution is entitled only to be reimbursed its costs (which may include overhead costs); and use of the licensed material in the course of research funded by a commercial or for-profit organisation.

Advisory

On 1st April 2026, Overton is changing how it handles institution data, migrating from GRID to ROR for all institution-related filtering and facets. If you have saved searches, you need to act. See their help page for details.

Key changes:

New filter names: "Cites or mentions institution" will be replaced with "Citing institutions" and "Mentioning institutions", as well as a new combined filter with the same name.

Updated institution names: To reflect what is available from ROR.

Potential search discrepancies: Previous searches may show different results. In many cases, there will be an increase in citations because of better detection and updated organisational structures.

Saved searches: Existing saved searches using the old filters will continue to function, but Overton recommends changing them to the new filters for optimal accuracy.