A selection of websites on international treaties:
A. Travaux Préparatoires
À la Recherche des Travaux Préparatoires: An Approach to Researching the Drafting History of International Agreements
Guide on searching for travaux préparatoires. Published by Jonathan Pratter (Foreign and International Law Librarian, Tarlton Law Library)
Audiovisual Library of International Law: Historic Archives
Access to the procedural history and related documents (including travaux préparatoires), as well as the text and status of selected legal instruments.
Collected Travaux Préparatoires
The Lillian Goldman Law Library (Yale Law School) has collected Travaux Préparatoires for international treaties that are available online or listed in its library catalogue.
What are Travaux Préparatoires and How Can I Find Them?
This website lists sources one can use to locate travaux préparatoires for UN multilateral treaties. Published by the Dag Hammarskjöld Library.
B. Treaty Texts
Avalon Project: Documents in Law, History and Diplomacy
Digital library of documents dating as far back as 4000 BCE. Developed and maintained by the Lillian Goldman Law Library, Yale Law School.
CIL Document Database
Database administered by the Centre for International Law (National University of Singapore) containing over 1400 ASEAN and international law documents in areas relevant to CIL’s research.
Core International Human Rights Instruments
Texts, ratifications and reservations of the 9 core treaties. Published by the Office of the United Nations High Commissioner for Human Rights. See also: Human Rights Instruments
Council of Europe: Treaty Office
Full texts of all conventions and agreements in the European Treaty Series (ETS) and Council of Europe Treaty Series (CETS). Published by the Council of Europe.
ECOLEX
Searchable database of multilateral environmental treaties and national legislation. Jointly operated by the FAO, IUCN and UNEP.
EUR-Lex: Treaties
Contains the founding, amending and accession treaties, as well as some protocols. See also: EU: Founding Agreements.
HCCH: Conventions and Other Instruments
Multilateral treaties drawn up and adopted by the Hague Conference. A status chart and "old" conventions (1902-45) are also available on this website.
IHL Databases: Treaties, States Parties and Commentaries
Databases containing treaties relating to international humanitarian law. Managed by the International Committee of the Red Cross.
International Investment Agreements Navigator
Database managed by UNCTAD. Treaties divided into 2 sections: Bilateral Investment Treaties (BITs) and Treaties with Investment Provisions (TIPs).
Labour Standards
Standards published by the International Labour Organization.
Language of Peace
Database "provides easy access to compare and collate language on key issues across 75,000+ provisions of around 1,000 peace agreements."
Maritime Space: Maritime Zones and Maritime Delimitation
Information on the deposits with the Secretary-General of the United Nations, pursuant to the United Nations Convention on the Law of the Sea, and the status of state practice. Maintained by the Division for Ocean Affairs and the Law of the Sea.
Space Law Treaties and Principles
UNOOSA publishes full texts of the space treaties and principles as well as selected travaux preparatoires.
UNCITRAL: Texts and Status
Full texts of all conventions and related texts administered by UNCITRAL.
UNIDROIT: Instruments
Access to international instruments prepared by UNIDROIT, including international Conventions and Protocols, Model Laws, Principles and Legal and Contractual Guides. Select the relevant subject in the right panel.
United Nations Treaty Collection
Access to the United Nations Treaty Series, League of Nations Treaty Series and Status of Treaties Deposited with the Secretary-General. Also includes publications like the Treaty Handbook and Final Clauses Handbook.
C. Guides
Treaties
Guide published by the Peace Palace Library.
UN International Law Documentation: Treaty Research
Research guide published by the Dag Hammarskjold Library.