Privacy Policy

The Japanese language version of this privacy policy is the official version. This translated version is provided solely for the convenience of our users. If there are any discrepancies or inconsistencies between the translated version and the Japanese version, the Japanese version shall take precedence.

In the operations of the “Mackerel” server monitoring service (hereinafter: “The Service”), in addition to having an awareness of the importance of protecting personal information and complying with applicable laws and ordinances related to said protection (hereinafter: “Personal Information Protection Laws”), Hatena Co., Ltd. (hereinafter: “The Company”) follows the privacy policy below (hereinafter: “The Privacy Policy”) and strives to handle and protect the personal data which contains users’ personal information appropriately. In addition, with the exception of cases where terms are defined separately within The Privacy Policy, all terminology used shall be considered to have the same definitions as in Personal Information Protection Laws.

Article 1: Definitions

  1. “Personal Information” Information related to an existing individual for which one or more of the following applies.
    1. Information which contains names, birthdates, or other data (recorded in writing, image format, or electronically, or expressed as audio, action, or by any other method) which could be used to identify a specific person (including cases where said data can be used in combination with other information which is easily accessible to identify a specific person)
    2. Individual identification codes
  2. “Information Related to Individuals” Access log information from the usage of The Service, information related to a communications device (such as a unique device ID or other differentiating information, location information, etc.), browsing history information for The Service acquired using cookies or other such resources, email addresses, account IDs, and other information related to individuals which cannot be used to identify a specific person.
  3. “Personal Data” This is a general term for all information related to the privacy of users of The Service (hereinafter: “The Users”), which includes all “Personal Information” and “Information Related to Individuals.”

Article 2: Acquisition of Personal Data

  1. The Company may acquire Personal Data in any of the situations defined below.
    1. When The Users register with The Service
    2. When information is automatically transmitted as part of usage of The Service by The Users
    3. When information is provided directly by The Users in writing or by some other means
    4. When information is provided by a third party with the consent of The Users
    5. When information is acquired legitimately through circumstances other than the above
  2. The Company may receive notifications from The Users or third parties which contains Personal Data or otherwise acquire publicly available Personal Data through legitimate means in some cases.

Article 3: Purposes for the Usage of Personal Information

  1. The Company acquires email addresses of The Users when they register for The Service and acquires names, phone numbers, and other personal information when inquiries are sent. This Personal Information is used for the purposes listed in the next clause.
  2. The Company uses the acquired Personal Information for the following purposes.
    1. Providing appropriate services to The Users through The Service (including services after the name or content of The Service has been changed for any reason)
    2. Providing content related to The Service such as contact information, promotion, and sales
    3. Investigating the content of inquiries related to The Service and providing response handling
    4. Handling actions in violation of The Company’s regulations, guidelines, etc. (hereinafter: “Regulations, Etc.”) related to The Service
    5. Providing essential notifications related to operation of The Service such as maintenance information and changes to Regulations, Etc.
    6. For purposes such as improvement, development, marketing related to The Service
    7. To analyze the route of inquiries, whether our e-mails have been opened, the Mackerel website access status, etc.
    8. To provide functionalities with the aim of improving convenience for our customers, such as recommendations based on access logs
    9. Carrying out obligations The Company has to The Users on The Service platform
    10. Creating anonymized statistical data related to The Service
    11. Other purposes related to the usage purposes listed above
  3. In addition, Personal Information acquired by The Company from The Service may be supplemented with other information acquired and possessed by The Company in some cases. Personal Information collected through The Service will not be used for any purposes exceeded the scope of usage defined at the time of collection.

Article 4: Purposes for the Usage of Information Related to Individuals

The Company uses acquired Information Related to Individuals for the following purposes. In addition, although the applicable information may be linked to Personal Information acquired by The Company in some cases, usage will be within the scope of the “Purposes for Usage of Personal Information” as defined in The Privacy Policy.

  1. Measurement of The Users traffic and analysis of activities
  2. Distribution, display, and effectiveness measurement of activity-targeted advertisements
  3. Confirmation of The Users and ensuring convenient usage
  4. Providing the ideal services for The Users
  5. Improvement of the quality of services
  6. Other purposes related to the usage purposes listed above

Article 5: Changes to the Purposes for Usage of Personal Information

The Company may change the scope of Personal Information usage to other purposes which can reasonable be determined related, and in the case of such changes, The Company may issue a notification to the individuals Personal Information refers to (hereinafter: “The Individuals”) or post the information about said changes in a place of its determination, making the changes to the purposes of usage publicly known.

Article 6: Limitations on the Usage of Personal Information

With the exception of cases where permitted by Personal Information Protection Laws and other related legislation, The Company will not handle Personal Information outside of the scope necessary for achievement of the purposes of usage without the consent of The Individuals. However, this restriction shall not apply in the following circumstances.

  1. When there are legal requirements
  2. When usage is necessary for protection of human life, health, or assets and getting consent from The Individuals is difficult
  3. When there is a special need for usage to improve public health or promote the healthy upbringing of children and getting consent from The Individuals is difficult
  4. When there is a need for cooperation with the national government, a local government organization, or a third party acting on behalf of such an organization for carrying out legally-mandated operations and getting consent from The Individuals would inhibit the accomplishment of said operations

Article 7: Safe Management of Personal Information

The Company strives for safe management of Personal Information to prevent loss, damage, falsification, leaks, and other risks, carrying out the essential and appropriate monitoring of its employees for this purpose. In addition, if The Company outsources all or a portion of Personal Information handling operations, The Company will carry out the essential and appropriate monitoring of the outsourcing site to ensure safe management of Personal Information.

Article 8: Provision to Third Parties

  1. With the exception of the circumstances defined in the clauses of Article 6, The Company will not provide Personal Information to any third party without prior permission from The Individuals. However, the following cases are not considered to be provision to a third party.
    1. Provision of Personal Information for the purpose of outsourcing all or a portion of Personal Information handling operations within the scope of achieving the purposes for usage of said information
    2. Provision of Personal Information to business personnel due to inheritance of operations resulting from a merger or other changes to The Company
    3. Provision of Personal Information following notification or other contact to The Individuals in accordance with Personal Information Protection Laws
  2. Notwithstanding the terms of clause 1 above, in addition to the exclusions of the clauses of Article 6, if The Company provides Personal Information to third parties (excluding groups with hierarchy meeting the standards designated by Personal Information protection committee regulations in Article 28 of Personal Information Protection Laws) located overseas (excluding countries designated by Personal Information protection committee regulations in Article 28 of Personal Information Protection Laws), The Company shall acquire consent from The Individuals for provision to overseas third parties in advance.

Article 9: Usage of Cookies and Other Technology

The Company uses cookies and similar technology in the process of carrying out services. These technologies are useful for monitoring the usage conditions of The Company’s services and are used for improving service quality. The Users who wish to disable cookies may do so by changing the settings in their web browsers. However, disabling cookies may make said users unable to use a portion of the functions of The Company’s services.

Article 10: Handling of Personal Information at Linked Sites

Although The Service may contain links to other websites in some cases, the provisions for handling of Personal Information in The Privacy Policy apply to Personal Information acquired through The Service. For information about these linked sites, please confirm the privacy policies on each page.

Article 11: Third Party Tracking System

The Mackerel website, including The Service, uses third party cookies and other third-party tracking. For details, see this page Site Policy.

Article 12: Inquiries

  1. For inquiries related to disclosure, opinions, questions, complaints, or other contact related to Personal Information handling, please use our inquiry form. In addition, please be aware that we will confirm the identity of the individual or their agent when inquiries are received.
  2. The website which provides The Service ( has a TRUSTe program license. TRUSTe is an organization founded with the goal of building confidence and trust in the Internet among users by promoting the proper usage of Personal Information. For all users of The Service, The Privacy Policy discloses all Personal Information acquired through The Service, and The Company gives permission to TRUSTe to investigate the handling conditions for said Personal Information. For inquiries related to the handling of Personal Information, please use the inquiries form mentioned in the previous clause to contact The Company. If you do not receive a response or are not satisfied with the answer from The Company, please contact TRUSTe. In this case, TRUSTe will act as an intermediary between The Users and The Service and strive to resolve the issue.

Article 13: Continuous Improvement

The Company regularly reviews operating conditions for the handling of Personal Information, striving for continuous improvement. As part of this process, The Privacy Policy is modified as necessary. When The Company determines that such a change is necessary, an announcement of the changes to be made will be issued prior to their implementation, with the time period prior determined by The Company. However, if the content of the changes requires the consent of The Users based on the provisions of laws or ordinances, The Company will use a separately-determined method to acquire said consent.


  • Established on April 1, 2022
  • Updated the company URL on August 5, 2022
  • Updated the page title on June 15, 2023