Altova DiffDog vs Difftastic
Altova DiffDog
altova.comDifftastic
difftastic.wilfred.me.ukSide by side
| Figure | Altova DiffDog | Difftastic |
|---|---|---|
| Price from | — | Free |
| Free plan | — | Yes |
| Free trial | Yes | — |
| Open source | — | — |
| Windows | Yes | Yes |
| macOS | — | Yes |
| Linux | — | Yes |
| Plans published | 2 | 1 |
| Spec score · Diff and Merge Tools | 8.3 (#4) | 7.7 (#15) |
| Purpose | DiffDog compares and merges text and source-code files, XML and JSON files, Word documents, directories, and database schemas and content. | Difftastic is a CLI diff tool that compares files based on syntax rather than line by line. |
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.
Difftastic
Difftastic is a command-line diff tool that compares files by syntax rather than matching lines alone. It identifies a file’s language, parses its code, and compares syntax trees with tree-sitter. The manual lists support for more than 30 programming languages, and the site names HCL, HTML, JSON, and YAML among supported formats. It can identify expressions that remain unchanged through whitespace or line-wrapping changes and show the files’ actual line numbers. Unsupported formats and extremely large inputs instead receive a conventional line-based diff with word highlighting. Difftastic can be configured as Git’s external diff command and used with Git subcommands; the manual also links configuration instructions for Mercurial, Fossil, and Jujutsu. Folder comparison and syntax highlighting are supported, while merge scope is two-way. Prebuilt binaries are available for Linux, macOS, and Windows, and the manual lists package-manager installation options. Difftastic is free, open source, and MIT licensed. The manual warns that Git 2.43.1 and earlier can crash when an external diff is used if file permissions have changed.