Differ Privacy Policy

Last updated: Nov 5, 2026

This policy explains what personal data Sky Valley Ambient Computing (“we”, “us”) collects when you use Differ: Player (app.getdiffer.com), the Differ phone app, Diff (diff.getdiffer.com), posts on differ.page and embedded on other sites, and our publishing and agent connection service (publish.getdiffer.com). It also explains what we do with that data and your rights over it.

We are the controller of your personal data under the UK GDPR and the Data Protection Act 2018.

Contact: Sky Valley Ambient Computing, 42–46 Princelet Street, London, England, E1 5LP — legal@skyvalley.ac

1. What we collect

When you sign in

• If you sign in with Google or Apple: your account identifier there and the email address it confirms for you. If you choose to hide your email from Apple, that’s the relay address Apple gives us. We don’t get your password, and we don’t keep Google or Apple access tokens.
• If you sign in with a code sent to your email: your email address.
• The handle you choose, and the date you chose it.

What you create and do on Differ

• Posts and drafts you upload, including their files, titles and each version you publish, and whether a post is a diff of another post.
• Your comments, follows, saves, your pinned post, posts and comments you report, creators you block, and what you’ve seen in your Activity tab.
• Contributions you make to live posts. Inside a post, you are known by an identifier specific to that post, not by your handle, email or account.
• Diff editor sessions: the prompts you write, the changes made, and what you publish.
• Diff choices you try or post in Player.
• Agent connections you approve (the tool’s name, the permissions you gave it, and when it was used). We store only hashed versions of their access tokens.

How you use Differ

• Views and engagement: which posts you view, for how long, whether they loaded, taps, shares and Diff it steps. These are linked to your account if you’re signed in, and to a random identifier for your browser either way.
• Product analytics (Player website): if you opt in to analytics, we use PostHog, hosted in the EU, to understand how people use Player: pages visited, actions taken, device and browser type and approximate location from your IP address. If you’re signed in, events are linked to your Differ account ID and handle. We remove secret parts of links before sending, and we don’t record your screen.
• Error reports (Diff): when Diff breaks, we send a technical error report to Sentry. It can include your browser, the page and technical details.
• Server logs: IP addresses, request times and similar technical data, used for security and running the Service.

Guest posts. If you publish without signing in, we store the post and a secret proof that lets you claim it later. We don’t know who you are.

We do not collect payment details, and we don’t sell your personal data or use it for third-party advertising.

2. Why we use it, and our legal basis

Where we rely on legitimate interests, you can object (see section 8).

3. What’s public

These can be seen by anyone: your handle, your profile, your published posts and their diffs, your comments, who you follow and who follows you, your pinned post, and counts such as how many diffs a post has. Search and the feed show published posts.

These are private: your email, drafts, saves, your reports and blocks, the analytics about you, and your Diff editor prompts. Creators see totals (views, viewers, saves) on their own posts, not who viewed them.

Content in a live post is visible according to that post’s own rules, which its creator sets. A post’s creator can see contributions made to it, attached to the post-specific identifier, not your handle.

4. AI processing

When a signed-in creator publishes or claims a post, we send the published post’s files and a running copy of it to AI and sandbox providers. This lets us analyse it and draw its icons and cover. When you use the Diff editor, your prompts and the post’s files go to the same kinds of providers to make your changes. We send the post’s content, not your email or account details. We use providers whose business or API terms don’t allow them to use this data to train their models.

5. Who we share it with

We use these service providers (“processors”) to run Differ. They process data only on our instructions:

We may also share data if the law requires it, to protect people’s safety or our rights, or with a buyer if Differ is sold or reorganised (they’d be bound by this policy).

6. International transfers

Some providers process data outside the UK, including in the United States. Where they do, we rely on UK adequacy regulations (such as the UK Extension to the EU–US Data Privacy Framework) or the UK International Data Transfer Addendum to the EU Standard Contractual Clauses.

7. How long we keep it

• Account data is kept until you delete your account.
• Posts and comments are kept until you or we delete them. Guest posts that aren’t claimed expire.
• Diff editor sessions are kept with the post they’re based on.
• Analytics and error data are kept only as long as we need them to understand and fix Differ, and are deleted automatically under our analytics (PostHog) and error-monitoring (Sentry) retention settings.
• Backups are kept for a limited period for recovery and security, then overwritten on a rolling basis. Deleted posts are never restored from them.

When you delete your account (in Player or the phone app, effective immediately; see how), we delete all your posts (drafts and live), saves, pin, follows, comments (with replies and reports on them), reports you made and reports of your posts, blocks you made and blocks of you, live-post contributions and agent connections. We also delete your account record, Google or Apple sign-in and email, and remove you from our email provider. Two things stay. Your views, shares and Diff it steps on other people’s posts remain only as anonymous counts. Diffs other people made of your posts remain. Your handle is reserved so nobody can impersonate you, but it no longer shows a profile. Data in analytics tools and backups expires on the schedules above.

8. Your rights

Under UK data protection law you can ask us to:

• give you a copy of your personal data;
• correct it;
• delete it (you can also delete your account yourself);
• restrict or object to how we use it, including any use based on legitimate interests;
• give you your data in a portable format;
• withdraw consent, where we rely on consent.

Email legal@skyvalley.ac. We’ll reply within one month. If you’re unhappy with how we’ve handled your data, you can complain to the Information Commissioner’s Office (ico.org.uk, 0303 123 1113). We’d appreciate the chance to sort it out first.

9. Cookies and similar technologies

We only set analytics cookies if you opt in, which you can do when you sign up. You can change your choice at any time in your settings. Essential and functional storage keeps working either way.

Posts are made by their creators and may use their own cookies or local storage inside their own differ.page origin. Those stay inside that post.

The phone app stores your sign-in securely on your device. It does not use analytics or advertising trackers.

10. Children

Differ is not for children under 13, and we don’t knowingly collect their data. If you think a child under 13 has an account, contact us and we’ll delete it.

11. Security

We use encryption in transit, encrypted session cookies, hashed tokens, isolated sandboxes for running and analysing posts, and a separate origin for every post, so posts can’t reach your account. No system is perfectly secure. If a breach puts you at risk, we’ll tell you and the ICO as the law requires.

12. Changes

We’ll update this policy as Differ changes and change the date at the top. We’ll tell you about significant changes in the Service or by email.