These AtCoder Terms of Use (hereinafter referred to as these “Terms”) set forth the relationship between AtCoder Inc. (hereinafter referred to as “we”, “our”, or “us”) and the Users of the Services that we provide.

Definitions

The defined terms used in these Terms are as follows:

1. “We” refers to AtCoder Inc.
2. Our “Website” refers to the AtCoder website located at https://atcoder.jp.
3. The “Services” refers to all services provided on our Website.
4. “Users” refers to all persons who use the Services.
5. “Members” refers to persons who have agreed to these Terms and have registered as Members in order to access Member services.
6. “Personal Information” refers to information such as e-mail addresses, etc. that can identify a specific individual.

Scope and Application of These Terms

1. By using our Website, it shall be deemed that Users have agreed to these Terms as well as any other terms of use, etc.
2. Other terms of use, etc. shall, irrespective of their respective name, constitute a part of these Terms.
3. In the event of any inconsistency between these Terms and the provisions of any other terms of use, etc., the provisions of the other terms of use, etc. shall prevail.

Compliance with These Terms

1. Users shall be deemed to have concluded an agreement with us concerning their use of the Services, and agree to use the Services in compliance with these Terms.

Revision of These Terms

1. We may revise these Terms for our convenience.
2. Unless otherwise specified by us, the revised Terms shall become effective from the time at which they are posted on our Website.
3. When using the Services after the revised Terms have taken effect, Users shall be deemed as having agreed to the revised Terms.

Handling of Personal Information

1. Personal Information shall be properly handled in accordance with our "Privacy Policy".

Membership

1. Users shall apply for membership through the prescribed procedures after having agreed to these Terms.
2. Those who have applied for membership will become Members upon our acceptance of their membership application.Those who have applied to become Members (hereinafter referred to as "Applicants") will become Members upon our acceptance of their membership application.

Cancellation of Membership

1. Members may cancel their membership through the prescribed procedures.

Member Accounts

1. Each individual Member shall have one account. Members may not hold multiple accounts, nor may they jointly hold a single account. However, the preceding restrictions shall not apply in special circumstances for which we provide our approval.
2. In no event shall Members be entitled to transfer or loan their account to a third party.

Operating Environment

1. We shall have no involvement in, and assume no liability whatsoever for, the User’s operating environment.

Responsibility of Users

1. Users shall use the Services at their own responsibility and at their own expense.
2. Users agree that in the event they cause damage to us through their use of the Services, they shall be liable to compensate for such damage at their own responsibility and at their own expense.
3. Users agree that in the event they cause damage to any other Members and/or third parties through their use of the Services, they shall be liable to compensate for such damage at their own responsibility and at their own expense, and hold us harmless from and against any liability resulting therefrom.
4. Users acknowledge that we have no obligation to store information, such as programs, etc., posted by Users using the Services. Accordingly, Users shall take the appropriate measures such as creating back-up copies of information as necessary.

Intellectual Property Rights

1. The ownership and copyright of any program posted on our Website through the use of the Services shall belong to the User who created it.
2. All rights (ownership, intellectual property rights, portrait rights, publicity rights and the like) associated with the text, images, programs, other data, etc. that constitute the Services shall belong to us or the third party who holds such rights, except for those created by Users themselves.
3. In the case where a User has posted on our Website a copyrighted work they created through the use of the Services, such User shall grant us a license to use such copyrighted work in our advertising and announcements.
4. With the consent of the User, we may provide third parties such as AI developers with the answer data posted on our Website through the use of the Services by such User and the log data, metadata, related thereto, as well as any other data authorized by such User, whether free of charge or for a fee, to be used as training data for machine learning and the like.
5. With respect to the copyrighted works to be used pursuant to the consent of or licenses granted by Users as set forth in the preceding two paragraphs, the respective authors shall not exercise their moral rights.

Use of Member Information and Registration Information

1. We shall be entitled to use the information of Members provided by Members when applying for membership for the operation of our company and the related business thereto.

Prohibited Matters

1. Users shall not engage in the following acts or acts which are likely to fall under the following categories during their use of the Services:
1. Acts contrary to public order and morals;
2. Acts in violation of domestic laws and regulations or applicable foreign laws and regulations;
3. Acts causing significant detriment to specific or non-specific third parties;
4. Acts of providing false information in the membership application;
5. Acts which cause or may cause damage to the Services or our company;
6. Acts of sharing a login ID with others; or
7. Other acts that we deem inappropriate.
2. If the acts of a User fall under any of the aforementioned items, we may revoke the membership of such User without the consent of such User.

Suspension of Use, Termination and Transfer of Our Website

1. We shall be entitled to temporarily suspend the provision of the Services, etc. without prior notice.
2. We shall be entitled to terminate our Website, etc. in whole or in part after having notified Users of the suspension and termination of our Website (i) if a malfunction in the equipment used to provide the Services, etc. occurs due to an act of God, including, but not limited to, fires or lightning strikes, (ii) if there is a need to carry out maintenance work on the equipment used to provide the Services, etc., or (iii) if we otherwise deem it necessary to temporarily suspend the provision of the Services, etc. for any other compelling reasons.
3. The preceding paragraph shall not apply if there are compelling reasons, in which case, we shall be entitled to immediately terminate our Website, etc. in whole or in part without prior notice.
4. If we transfer our Website to a third party, Users shall comply with the instructions of the transferee.

Disclaimer

1. We assume no liability for any defects, temporary interruptions, partial deletions, revisions, or termination of the content of our Website and any damage suffered by Users or third parties arising therefrom.
2. We assume no liability for, and make no warranties as to, the legality, completeness, reliability and accuracy of the content of our Website, the information posted by Users, and the services provided by the destinations linked to from such information.
3. We assume no responsibility in relation to any issues or disputes among Users or between Users and third parties in connection with the Services we provide.
4. We assume no obligation to compensate for any damage arising from delayed or non-delivered e-mails, erroneous displays on our Website or the dedicated Members’ page or any other causes whatsoever caused by the failure of systems, etc. used to provide the Services.
5. We assume no responsibility or liability whatsoever for any delay, modification, interruption, discontinuance or termination of our Website, the loss of any information provided through our Website, or any other damage arising in connection with the Website.
6. We shall be entitled to revise the content of our Website at any time and for any reason.

Governing Law and Competent Jurisdiction

1. The rights and obligations of Users in connection with these Terms shall be governed by and construed in accordance with the laws of Japan.
2. The Tokyo District Court shall be the court of first instance with jurisdiction over any litigation arising out of or in connection with these Terms.

Supplementary Provisions

1. These Terms shall come into effect on February 1, 2012.
2. Please note that these Terms of Use were revised and applied on June 29, 2026.
3. These Terms shall also apply to any acts carried out by Users prior to the enforcement of these Terms.