Altova DiffDog vs KDiff3
Altova DiffDog
altova.com
KDiff3
apps.kde.orgSide by side
| Figure | Altova DiffDog | KDiff3 |
|---|---|---|
| Price from | — | Free |
| Free plan | — | Yes |
| Free trial | Yes | — |
| Open source | — | Yes |
| Windows | Yes | Yes |
| macOS | — | Yes |
| Linux | — | Yes |
| Plans published | 2 | 2 |
| Spec score · File Comparison Software | 8.3 (#4) | 8.2 (#10) |
| Spec score · Diff and Merge Tools | 8.3 (#4) | 8.3 (#8) |
| Purpose | DiffDog compares and merges text and source-code files, XML and JSON files, Word documents, directories, and database schemas and content. | KDiff3 compares and merges files and folders. |
Plans
Altova DiffDog
- DiffDog 2026 Professional Edition$189, paid once
- DiffDog 2026 Enterprise Edition$269, paid once
In their own words
Altova DiffDog
Altova DiffDog has no write-up on Specifiction yet; its figures are above.
KDiff3
KDiff3 is a free, open-source desktop app for comparing and merging files and folders on Linux, macOS, and Windows. It can compare two or three text files or folders, showing differences line by line and character by character. For merge work, it can combine changes automatically and includes an editor for resolving conflicts, including three-way merges. Folder comparison and Git integration are supported. KDiff3 handles Unicode, UTF-8, and other file encodings; users can highlight or hide whitespace and comment changes, and print differences. It also supports version-control keyword and history merging, with network transparency through KIO. Its listed license is GPL-2.0-or-later. The Free plan costs nothing, and there is no free trial. Linux installation options include Discover or another AppStream store, a distribution package manager, or Flathub. The app page links to a handbook, forum, and bug-reporting page. KDE describes itself as an international community building and distributing free, open-source software since 1996.