Diffoniq™

Windows File/Directory/Archive Difference Viewer
formerly WDiff32

Diffoniq shows what changed — between two text files, two folders or two archives, side by side. And it lets you act on the answer: merge marked areas from one side to the other, copy them out, synchronize whole folders, or hand the result over as a report.

What it does best

Text comparison Side-by-side panes with in-place editing: merge marked areas between the sides, paste and delete lines with multi-level undo, and save with an automatic backup. Full Unicode — UTF-8/UTF-16 files and international filenames throughout.
Folder comparison Compares whole trees fast — even very large ones — and verifies equal-sized pairs by content in the background, backed by a persistent hash cache that makes repeat runs almost free. Renamed and moved files are recognized as pairs instead of appearing as added + deleted.
Archives ZIP, 7-Zip, RAR, tar (also compressed), CAB and ISO open like folders — nested archives to any depth, renamed archives are recognized by their content. Compare an archive against a folder or against another archive.
Converters Compare PDF, Word, SQLite, image metadata and other foreign formats as text through user-configured external converters — converted views are marked, read-only, and cached.
Synchronization Turn a folder comparison into action: mirror or update, previewed first, Recycle-Bin deletions, both directions — interactively or headless for the Task Scheduler.
Reports Export the comparison as a self-contained HTML page, plain text or JSON — evidence you can mail, archive or feed to a script.
Scripting & AI Everything above also runs without a window: /report and /sync answer through exit codes and output files that appear only complete — built for batch files, CI jobs and AI assistants.
Works with your tools Drop-in diff viewer for git difftool, TortoiseGit/TortoiseSVN, Total Commander, WinSCP and the common IDEs — opens straight into the comparison, read-only where the host expects it.

New in this release? What’s New has the full list.

Where to go next

Looking for something specific? The search box above the contents tree searches every help page — results show the matching sentence.