Privacy Policy
The app generates images on your device and never sends us your prompts or images.
Effective 16 October 2026.
Who we are
Numen Technologies Limited makes Private Diffusion and is the data controller for the processing described here.
Numen Technologies Limited
Work Hub, 77 Camden Street
Dublin D02XE80
Ireland
Registered in Ireland with CRO number 677823.
For any privacy question or request, write to us at [email protected].
What this policy covers
This policy covers the privatediffusion.ai website and the Private Diffusion app for iPhone, iPad, and Mac.
The app and website are separate systems and are described below. The app collects nothing.
This policy does not cover other companies. When your device downloads a model, saves an image to your photo library, or syncs your gallery or app preferences to your iCloud, you are dealing with Apple under Apple's own privacy policy, and we are not responsible for what it does with your data.
We publish this policy in several languages. The English version is the one that controls. If a translation and the English text disagree, the English text applies.
The Private Diffusion app
The app collects no personal data, and neither do its two extensions, one that downloads models and one that shows your favorites in a widget. None of them tracks you or contacts tracking domains. There is no account, no sign-up, no analytics SDK, no advertising SDK, and no crash-reporting service in any of them.
Generation happens on your device. The model runs on your device's own silicon, and there is no Numen server in that loop, so your prompt, your generation settings, and the image that comes out of them are never sent to us.
- Your prompts and your images: they live in the app's gallery on your device.
- iCloud sync: if you are signed in to iCloud, your gallery and a few app preferences sync through your own iCloud account under Apple's terms. We do not have access to your iCloud data.
- Model downloads: you download a model inside the app, and Apple delivers it through its App Store services. Nothing about your prompts or your images travels with it.
- Saving to your photo library: the app can add an image you chose to save to your photo library. Its access is add-only. It cannot read, search, or browse the photos already there.
- Locking the gallery: hidden images sit behind Face ID, Touch ID, or your device passcode (your login password on a Mac). Apple's system authentication performs the check and tells the app only whether it succeeded. No biometric data reaches the app, and none reaches us.
- Sensitive-content checks: the app checks for sensitive content on your device. Nothing is uploaded to be checked, and no result is reported to us. Before you reveal an image it flagged, the app may ask your device for your age range, which you can decline to share. The answer is not stored and never reaches us.
- Purchases: any payment happens on the App Store and is handled by Apple. The app takes no payments itself and holds no payment data.
- API server mode on the Mac: the Mac app can start a local image-generation server. It stays off until you start it, and every image it returns is generated on that Mac. We are not in that exchange and see none of it.
The app is distributed through the App Store. Apple, as App Store distributor and independent controller for purchases and iCloud, handles purchase and iCloud data under its own privacy policy.
The models are published by other people. Once a model is on your device it runs there and reports to nobody.
The privatediffusion.ai website
The website is a different surface from the app. It is a marketing site for the app, including a support page where you can write to us.
You give us personal data when you contact us, including through the support form. The site also collects the limited analytics and error data described below.
The support form
The support page carries a form for writing to us. It asks for your name, your email address, what your message is about, and the message itself. If you tell us you are reporting a technical problem, it also asks which platform you are on and which device you have, because on-device generation behaves differently on different hardware.
We use what you send to respond to your request and keep it only as long as needed for that purpose.
Send only what you are willing to share.
We use a bot-protection provider and usage limits to protect the form from abuse.
Analytics
We use analytics to understand how the website is used.
It records usage data (the pages you visit, including any campaign tags or advertising click IDs an inbound link carries, referring sites, and actions such as a button click), device and browser data, and an approximate location derived from your IP address. We do not use analytics to build profiles across other websites. Where your browser holds the analytics identifier, these events carry it.
We use IP addresses to derive approximate location and do not keep them in our analytics records.
The app does none of this. It carries no analytics at all.
Analytics identifier
We keep a random identifier in your browser so that your visits to this site are counted as one visitor rather than many.
Clearing this site's data removes the identifier, and any identifier you are given after that is a new one.
If your IP address places you in the European Union, the European Economic Area, the United Kingdom, or Switzerland, we do not keep this identifier on your device, and we delete one stored on an earlier visit. Elsewhere we rely on our legitimate interest.
Error reports
When something on the website breaks, your browser can send an error report to our error-monitoring tools. The report describes the failure so we can fix it.
We limit these reports to what we need to diagnose problems.
We also collect technical performance data to keep the site fast and reliable.
We do not receive crash reports or error reports from the app itself.
Cookies and browser storage
The table below describes the cookies and similar technologies we use.
| Name | Type | Purpose | Duration |
|---|---|---|---|
| Language preference | First-party cookie | Remembers the language you are reading the site in, so later visits land in the same one. Strictly necessary for delivering the site in that language. | Until you close the browser |
| Theme preference | First-party local storage | Remembers whether you chose the light or the dark theme. | Until you clear it |
| Analytics identifier | First-party local storage | A random value issued by our servers so that your visits are counted as one visitor. Not strictly necessary, so we store it only for visitors outside the European Union, the European Economic Area, the United Kingdom, and Switzerland, under our legitimate interest. | No set end: clearing your site data removes it |
| Campaign label | First-party session storage | When you arrive through a link that names one of our marketing campaigns, remembers that campaign name so that a download you start from the App Store during this visit is counted towards it. | Until you close the tab |
| Logo animation flag | First-party session storage | Records that the animated logo has already played its entrance, so it does not replay on every page. Not personal data. | Until you close the tab |
| Cloudflare Turnstile | Third-party security challenge | Tells a person from a bot on the support form. | Per challenge, set by Cloudflare |
| cf_clearance | Cookie, set by Cloudflare | Set by Cloudflare when it needs to challenge suspicious traffic; used for security. | Short-lived, set by Cloudflare |
Why we process data, and on what legal basis
Every purpose we process data for needs a legal basis under the GDPR. The table below sets them out.
| What we do | Data involved | Legal basis (GDPR) |
|---|---|---|
| Answer a message you sent us | Your name, your email address, what your message is about, and whatever you write. For a technical report, also the platform and device model you select | Article 6(1)(b) and Article 6(1)(f), answering your request |
| Block bots and keep the support form available | Connection and device data used for security | Article 6(1)(f), our legitimate interest in a form that survives abuse |
| Measure how the site is used | First-party page and event data, carrying the analytics identifier where your browser holds one | Article 6(1)(f), our legitimate interest in improving our own site |
| Count return visits to this site | A random analytics identifier held in your browser | Article 6(1)(f), our legitimate interest |
| Diagnose errors | Error reports and performance measurements | Article 6(1)(f), our legitimate interest in a working service |
| Meet legal obligations, including accounting and tax | Records Apple and our accountants require | Article 6(1)(c), legal obligation |
Who else is involved
These providers process data on our behalf:
- Our hosting provider - runs our servers.
- Our content delivery and bot-protection provider - delivers and protects the site, and stores encrypted backups.
- Our email delivery provider - carrying support-form messages to our inbox.
We do not sell personal data, and we do not share it for cross-context behavioral advertising. We disclose data to a public authority only where the law requires it.
How long we keep things
We keep little:
- Messages you email us: kept in our mailbox for as long as we need them to deal with your request.
- Website analytics: event records, kept for as long as we need them to understand how the site is used. The IP address behind a visit is not stored.
- Error reports and performance measurements: kept while they are still useful for fixing the fault or keeping the site fast.
Backups are kept for a limited period and then overwritten.
International transfers
We are an Irish company. Some of the providers listed above are established in the United States and may process data there or in other countries.
The safeguard for each transfer depends on that provider's arrangement: either an adequacy decision or the European Commission's standard contractual clauses, as required by Chapter V of the GDPR. Contact us if you need the current details for a particular provider.
Security
We use technical and organizational safeguards to protect personal data.
Children
Private Diffusion is a general-audience creative tool. It is not directed at children, and we do not knowingly collect personal data from children. If you think a child has sent us personal data, write to [email protected] and we will delete it.
Changes to this policy
We update this policy when what we do changes. The effective date at the top always tells you which version you are reading.
Your rights
Which rights you have depends on where you live. To exercise any of them, write to [email protected]. We answer within the time the applicable law allows. Requests are free of charge except where the law allows otherwise. We may need to verify your identity.
We may hold support correspondence you sent us, website analytics records, and website error reports. If your browser holds the analytics identifier, you can send us that value and we can find the analytics events recorded against it.
European Union and European Economic Area (GDPR)
You have the right to access your personal data, to have inaccurate data corrected, to have data erased, to restrict or object to processing, to receive your data in a portable format, and to withdraw consent at any time where we rely on consent. Withdrawing consent does not affect processing that already happened.
Where we rely on legitimate interests, you can object on grounds relating to your particular situation, and we will stop unless we have compelling grounds that override yours.
Our lead supervisory authority is the Irish Data Protection Commission. You can complain to it, or to the authority in the country where you live. The list of national authorities is published by the European Data Protection Board.
United Kingdom (UK GDPR and Data Protection Act 2018)
You have the same set of rights described above. You can complain to the Information Commissioner's Office at ico.org.uk.
Elsewhere
Depending on where you live, local law may give you additional rights. Write to [email protected] and we will deal with your request.
Contact us
Privacy questions, requests, and complaints all go to the same address: [email protected]
The terms that govern your use of this site are in our Terms of Use.