Support

How to reach us, and where to look first.

Documentation

The Diffoniq help is the complete handbook — the same pages the program opens with F1. It is the fastest answer for most questions about comparing files, folders and archives. What changed in 2.0 is in the changelog.

Frequently asked questions

Can I try Diffoniq before I buy?

Yes. The download is the complete program, free to evaluate for 30 days with no functional limits. An unlicensed copy only shows an evaluation reminder.

How do I enter my licence?

Your licence arrives by e-mail as a small licence file. In Diffoniq, open Help → License… and load the file or paste the licence block — details in the help. For company-wide installs the MSI takes the licence file directly; see unattended installation.

I lost my licence.

Reply to your delivery e-mail or write to support@diffoniq.com — we re-send it free of charge.

I have a WDiff32 registration. Do I have to buy again?

No. Registered WDiff32 users get a one-time free Diffoniq 2.x licence matching what they registered. Claim it on the upgrade page.

Are updates included?

A 2.x licence covers every 2.x release. A future major version is a separate purchase. The program can check for new versions itself (Help → Check for Updates…). From 2.0.3 on it can also install them: choose Install update, and Windows asks for your permission. Nothing is downloaded or installed without your click.

I updated, but About still says “Version 2.0”. Did the update work?

Yes. Up to 2.0.1, About shows only the version line, 2.0; from 2.0.2 on it shows the full number, for example Version 2.0.2. With an earlier version the full number is shown by Help → Check for Updates…, in Windows under Settings → Apps → Installed apps, and in the file properties of Diffoniq.exe (Details tab).

Does it run on my machine?

Windows 10/11, 64-bit. Windows on ARM: runs under the built-in x64 emulation — there is no native ARM64 build, and we do not test on ARM hardware. On 32-bit Windows, WDiff32 1.59 remains available on the company site.

Windows says “Windows protected your PC”.

Windows may show a SmartScreen notice (“Windows protected your PC”) for a new release until it has built up reputation. Check that the publisher is C.Sitte Softwaretechnik e.U., then choose More info → Run anyway. The installer and the program inside the ZIP are Authenticode-signed.

Can I get my money back?

Yes, a full refund within 30 days of purchase — see the Refund Policy.

Questions, bug reports, licence matters

Write to support@diffoniq.com. Please include:

For a comparison that goes wrong, the sizes and types of the files or folders involved are usually what makes a report reproducible.

Security reports

Please report suspected vulnerabilities to security@csitte.com — this is our dedicated security contact, published in security.txt. Please do not use it for ordinary support questions; that only slows both queues down.

Existing WDiff32 licences

Licences bought for WDiff32 remain valid. Your registration entitles you to a one-time free Diffoniq 2.x licence — the Upgrades section of the licence terms says what it covers. If you have lost your registration details, write to order@diffoniq.com from the address you registered with, or tell us the name it was registered to.

Free licences

Free licences for open-source developers and reviewers. If you maintain an active open-source project or review software for a publication, write to order@diffoniq.com with a link to the project or the publication.

Who you are writing to

Diffoniq is developed by C.Sitte Softwaretechnik e.U., a one-person company in Mattsee, Austria — see the Imprint. Replies come from a person, not a ticket system, so please allow a few working days.

For company matters rather than product ones — legal notice, data protection requests under the GDPR — the address is contact@csitte.at.

Last updated: 15 October 2026.