Draft (v0.16, 2026-09-28). This text describes what the software actually does, but it has not been reviewed by a lawyer yet.
Privacy Policy
LexiBrain is operated by Henry (an individual). Contact: hello@lexibrain.net.
LexiBrain is a vocabulary-learning web app. Every feature is free; to keep learning after the 4-minute vocabulary test you create a free account. We collect as little personal data as we can, we never sell it, and we never use it for advertising. We use no third-party analytics, advertising or tracking.
1. Before you create an account
You can choose a language, make a plan and take the vocabulary test without an account. Your progress (which words you studied, quiz answers, review schedule, settings, interface language) is stored only in your own browser (localStorage). You can export it to a file or delete it from the menu at any time. When you create an account, it is copied into your account (section 2). Fonts and the 3D engine are served from our own server.
2. Your account
- Email address — to identify your account and send you verification codes and important account messages (for example a password reset). We do not send marketing email.
- Password — stored only as a salted scrypt hash; we cannot see your password.
- Age group — asked when you sign up, stored only on your device (not sent to us), and used to tell you whether you need a parent's or guardian's consent.
- Learning progress — a copy of the progress described above, so it is kept safe and synced between your devices.
- Interface language and the date your account was created.
- Sign-in session — a random token in a cookie (
lb_sid) that is strictly necessary to keep you signed in; it expires after 30 days of inactivity. We store only a hash of it, together with your browser's user-agent string and IP address, so you can recognise your sessions and so we can detect abuse. - Security log — sign-ins, failed sign-ins, password changes and account deletion, with time and IP address, used only to protect accounts.
Verification codes expire after 15 minutes. Email is delivered through an email provider acting on our behalf.
3. Usage statistics
To know how many people use LexiBrain, how often, in which countries, and which features help, our own server counts, per day: which features were used and how many times (for example "started learning", "opened a word card", "switched to the planet shape"), the interface language, the language you are learning, the device type (phone, tablet or computer), the channel label of the link that brought you (for example ?ref=reddit, if the link had one) and the country. The country is looked up on our server from your IP address using the IP to Country Lite database by DB-IP; the IP address itself is not stored for statistics.
We do not collect which words you study, your answers, exact times or your precise location. If you are signed in, the counts are linked to your account. If you are not, they are counted under a daily visitor code computed from your network address, your browser's user-agent and a random value that changes every day and is then thrown away, so we cannot recognise the same visitor on another day, and nothing is stored in your browser for this.
You can turn usage statistics off in Settings ("Send usage statistics") on each device. In the "use it on this device only" mode for younger users, nothing is sent at all.
4. Feedback
If you send feedback, we store what you write, the kind you chose, the email address you give (optional; if you are signed in we suggest your account email), the country looked up from your IP address, and — unless you untick it — technical details (app version, interface and learning language, the page you were on, the word you reported, screen size, browser). We use it to fix problems, improve content and reply to you. A notification with the same content is emailed to us.
5. Why we use it (legal bases)
To provide the account and sync service you asked for (performance of a contract); to keep the service secure and to understand and improve it through usage statistics and feedback (legitimate interest — you can object by turning statistics off or contacting us). Where a law requires consent — for example for transferring personal information of users in mainland China abroad — creating an account is done with your consent, which you can withdraw by deleting the account.
6. How long we keep it
Account data and synced progress are kept until you delete your account. Deleting the account removes the account, sessions, codes, synced progress and your usage-statistics details from our database immediately, and removes your email address from any feedback you sent. Per-person daily usage details are kept for 180 days; after that only daily totals remain (no account or visitor code). Feedback is kept while it is useful for improving LexiBrain; you can ask us to delete it. Database backups are used only to restore the service after a failure and are deleted automatically once they are 30 days old, so deleted data can remain in a backup until then. Security-log entries are kept for up to 180 days.
7. Your rights
In the app (Menu → Account) you can download all your data as a JSON file (including your usage-statistics details and the feedback you sent), change your password and permanently delete your account. You can also contact us to access, correct or delete your data, or to object to processing. Depending on where you live (for example the EU/UK GDPR, California CCPA/CPRA, China PIPL, Brazil LGPD) you may have additional rights, including complaining to a data-protection authority.
8. Where the data is stored
Our server is run on Amazon Web Services (Amazon Lightsail) in the US East (Ohio) region, in the United States. Daily backups of the database are kept on the same server and deleted automatically once they are 30 days old. Data travels between your browser and our server encrypted (HTTPS). If you use LexiBrain from another country or region, including mainland China, your data is transferred to and processed in the United States with the safeguards required by law.
9. Children
LexiBrain is designed for learners of all ages, but accounts are for people aged 16 or older. Younger users cannot create an account yet (a parent or guardian consent process is planned); they can use LexiBrain "on this device only", where no personal data leaves the device and no usage statistics are sent.
10. Changes and contact
We will announce material changes in the app before they take effect. Contact: hello@lexibrain.net.
隐私政策（中文）
词脑由 Henry（个人）运营。联系邮箱：hello@lexibrain.net。
草稿（v0.16，2026-09-28）。内容按软件的实际行为写成，正式发布前需要法务审核。
词脑是一个背单词的网页应用，所有功能都免费；做完 4 分钟词汇量测验以后，注册一个免费账号就能接着学。我们尽量少收集个人信息，不出售，也不用于广告；不用任何第三方的统计分析、广告或追踪。
1. 注册之前
不注册也能选语言、定学习计划、做词汇量测验。学习记录（学过的词、测验、复习安排、设置、界面语言）只保存在你自己的浏览器里（localStorage），随时可以在菜单里导出成文件或清空。注册以后会复制到你的账号里（第 2 条）。字体和 3D 引擎从我们自己的服务器加载。
2. 账号
- 邮箱：识别账号，发送验证码和重要的账号通知（例如找回密码）。不发营销邮件。
- 密码：只保存加盐的 scrypt 哈希，我们看不到你的密码。
- 年龄段：注册时问，只存在你的设备上（不发给我们），用来告诉你是否需要父母或监护人同意。
- 学习记录：上面说的学习记录的副本，用来保存好、在你的设备之间同步。
- 界面语言、注册时间。
- 登录状态：Cookie（
lb_sid）里的随机令牌，保持登录所必需；30 天不用自动失效。我们只保存它的哈希，以及浏览器标识和 IP 地址，用来识别会话、发现滥用。 - 安全日志：登录、登录失败、改密码、删号的时间和 IP，只用于保护账号。
验证码 15 分钟后失效。邮件通过受我们委托的邮件服务商发送。
3. 使用统计
为了知道有多少人在用、多久用一次、在哪些国家、哪些功能有用，我们自己的服务器按天记录：用了哪些功能、各用了几次（例如"开始学习""打开单词卡""换成星球形态"），界面语言，学的语言，设备类型（手机、平板、电脑），带你来的链接上的渠道标签（例如 ?ref=reddit，链接上有才记），以及国家。国家由我们的服务器根据你的 IP 地址查 DB-IP 的 IP to Country Lite 数据库得到；统计里不保存 IP 地址本身。
我们不收集你学的是哪些词、你的答案、精确的时间或精确的位置。登录了的，计数和你的账号关联；没登录的，按"当天的访客编号"计数——由你的网络地址、浏览器标识和一个每天更换、用完即丢的随机值算出来，所以第二天就认不出同一个访客，你的浏览器里也不为此存任何东西。
可以在"设置"里关掉"发送使用统计"（每台设备分别设置）。给年龄较小的用户的"只在这台设备上用"模式，什么都不会发送。
4. 反馈
你发送反馈时，我们保存你写的内容、选的类型、你留的邮箱（可不填；登录了会预先填上账号邮箱）、根据 IP 查到的国家，以及（除非你取消勾选）技术信息：版本、界面语言和学的语言、所在页面、报告的词、屏幕大小、浏览器。用来修复问题、改进内容、回复你。同样的内容会发一封通知邮件给我们。
5. 使用的依据
提供你要求的账号和同步服务（履行合同）；保障服务安全，并通过使用统计和反馈了解、改进服务（正当利益——你可以关掉统计或联系我们提出反对）。法律要求同意的情形（例如把中国大陆用户的个人信息传到境外），注册即表示同意，删除账号即撤回。
6. 保存多久
账号和同步的学习记录保存到你删除账号为止。删除账号会立即从数据库删除账号、会话、验证码、学习记录和你的使用统计明细，并从你发过的反馈里删掉你的邮箱。按人按天的使用统计明细保存 180 天，之后只留下每天的总数（不再有账号或访客编号）。反馈在对改进词脑有用时保存，你可以要求删除。数据库备份只用于服务出故障时恢复，满 30 天自动删除；在那之前，已删除的数据还可能留在备份里。安全日志最多保存 180 天。
7. 你的权利
在应用里（菜单 → 账号）可以下载全部数据（JSON 文件，包括你的使用统计明细和发过的反馈）、修改密码、永久删除账号。也可以联系我们查询、更正、删除数据或反对处理。根据你所在地的法律（例如欧盟/英国 GDPR、美国加州 CCPA/CPRA、中国《个人信息保护法》、巴西 LGPD），你可能还有其他权利，包括向监管机构投诉。
8. 数据存放在哪里
服务器在美国：亚马逊云（Amazon Web Services 的 Amazon Lightsail）美国东部（俄亥俄）区域。数据库每天的备份放在同一台服务器上，满 30 天自动删除。数据在你的浏览器和我们的服务器之间加密传输（HTTPS）。从其他国家或地区（包括中国大陆）使用词脑时，你的数据会按法律要求的保障措施传到美国处理。
9. 未成年人
词脑适合各年龄的学习者，但账号面向 16 岁及以上的人。更小的用户现在还不能注册（父母或监护人同意的流程在计划中），可以选"只在这台设备上用"：个人信息不离开设备，也不发送使用统计。
10. 变更和联系
重要变更会提前在应用里说明。联系：hello@lexibrain.net。