Privacy Policy

Your files stay on your device

All file parsing and comparison runs locally in your browser. The files you compare, their contents, and the resulting diffs are never uploaded to us or to any third party. We have no server that receives your documents.

The same applies to folder comparison. When you compare two folders, the directory structure, file names, relative paths, sizes, timestamps, and any content hashes are computed entirely on your device — none of it is transmitted. Copying and mirroring write only to the local folders you select, and the operation receipt is generated and downloaded locally, never sent anywhere.

On some browsers, selecting a folder triggers a built-in prompt asking whether you want to “upload” its files. That is the browser’s own generic wording for granting a web page read access to a folder — it does not mean anything is sent to us. Diffesq reads the files locally in your browser tab and transmits none of them.

What we collect

• Purchase information — when you buy Pro, payment is handled by Stripe, our payment processor. Stripe receives your email address and payment details; we do not store your card data. See Stripe's privacy policy at stripe.com/privacy.
• License records — to validate your purchase we store a license key, the plan, device identifiers for the devices you activate, and the associated Stripe subscription/checkout identifiers. We do not store your name or file contents.
• Newsletter email — if you explicitly subscribe to our newsletter, we store your email address with Loops, our email provider, to send you occasional product updates. Every email includes an unsubscribe link, and you can request deletion at any time. We never add you without your explicit opt-in.
• Preference sync (optional, off by default) — if you turn on preference sync in License & account, we store your saved comparison profiles, your saved filter presets, and your folder filter selections against your license key, so they are available on your other devices. This includes text you typed: the names you gave your profiles, the names you gave your saved filter presets, and the filter patterns you wrote. It does not include your files, their names, their paths, their contents, anything extracted from them, or any record of which files or folders you compared. The stored record has no field capable of holding them. Sync is off until you explicitly turn it on. It is available only on an active Pro license, and you can view everything stored for your license and delete it at any time from License & account. Turning off sync removes the preferences from our servers.
• Anonymous usage analytics, no ad tracking — we measure how the site is used (pages viewed, buttons clicked) with anonymous, cookieless analytics (PostHog). These events carry no identity: no cookies, no persistent identifiers stored on your device, and no cross-site tracking. Analytics never sees your files — no file names, contents, or anything derived from them — and the comparison, folder, and export pipelines emit no analytics events at all. We honor the Do Not Track and Global Privacy Control browser signals. There are no advertising or cross-site tracking scripts. We use local browser storage only to remember your license and device on this device.

How we use it

Purchase and license data is used solely to process payments, issue and validate licenses, provide support, and comply with legal obligations. We do not sell your data.

Data retention & your rights

We keep license records for as long as your license is active plus any period required for tax and accounting. A preference record is deleted when you turn off sync, and when a license is revoked following a refund or chargeback. If a subscription simply lapses, we keep the record and syncing stops until the license is active again — nothing you wrote should disappear because you stopped subscribing. You may request access to or deletion of your license data by emailing [email protected]. Payment records held by Stripe are subject to Stripe's own retention policies.

Contact

LoudFoam LLC · [email protected]