Privacy Policy

Last updated: September 2026

The short version

Your DICOM files — and the patient data inside them — never leave your device. All parsing, rendering and metadata display happen locally in your browser. Our servers never receive the files, any pixel data, any patient identifier, or anything else from them. This design is deliberate: medical images carry protected health information, and the only tool you can fully trust with it is one that never transmits it.

What we do NOT collect

• Your DICOM files — they are read by JavaScript running in your browser tab and are never uploaded.
• Image content and metadata — pixel data, patient names, IDs, study descriptions and anything else in the file stay in your browser's memory and are discarded when you close the tab.
• Accounts and cookies — the site has no signup, and it sets no cookies.

What is stored on your device

Nothing. The viewer keeps everything in memory for the session and persists nothing to localStorage, IndexedDB, or cookies.

What is sent over the network

• Page & library loads. The site is static files served by our hosting provider (Vercel), and one open-source library (dcmjs, the DICOM parser) is loaded from jsDelivr. Like any web request, these providers may log your IP address and user agent per their own privacy policies.
• Anonymous usage statistics. We use Vercel Web Analytics, which counts page views and referrers without cookies and without collecting any file or personal data.
• Anonymous usage counters. Our server keeps running counts of tool events: files were parsed (count and byte size only) and client-side error codes (e.g. "compressed pixel data not supported"). These are bare numbers and codes — they never include file names, patient identifiers, tags, pixel data, or any file content.
• Feedback you choose to send. The Feedback link opens a form delivered by Web3Forms: only the text you type and, if you fill it in, your reply email address are sent. Never paste patient information or file content into the feedback form — we cannot use it and do not want it.

Data retention

Your files and their contents are never sent to us, so there is nothing for us to retain or delete. Anonymous usage counters (numbers only, as described above) are kept as daily aggregates and lifetime totals.

Changes to this policy

If we ever change how data is handled, we will update this page. Any feature that would require sending file content to a server (we have none planned) would be opt-in and clearly marked before it affects you.

Contact

Questions about privacy? Email hello@dcmview.com.