Headlog is a free, personal-use headache diary. It is not a medical device and is not intended to diagnose, treat, cure, or prevent any condition. It is not a substitute for professional medical advice. Always consult a qualified clinician about your health.

Privacy. Headlog does not ask for your name, date of birth, or any identifying information. All entries are stored only in your device's browser storage. Nothing is transmitted to the developer, no account is created, and no data is sent to any server. The developer cannot see your entries and cannot recover them if you clear your browser data or change devices.

HIPAA notice. Headlog is a consumer tool, not a service offered by or on behalf of any healthcare provider, insurer, or HIPAA-covered entity. Using Headlog does not create a provider–patient relationship. If you choose to share an exported PDF with a clinician, that exchange is between you and them; Headlog plays no part in it.

Use at your own risk. By using Headlog you accept that the developer is not liable for any consequences arising from its use, including data loss or any decision made based on tracked information.