DiffCompanion is a fast, local-first desktop diff & merge tool — everything you expect from Beyond Compare (text, folders, tables, hex, images, registry, archives, sync) plus HTML/CSV reports, a command-line mode, and a bring-your-own-key AI assistant.
Free & open-source (MIT) · Grab an installer from Releases — or build from source: git clone https://github.com/xShiroeNguyenx/diff-companion && pnpm install && pnpm tauri:dev
From a single file diff to a full folder sync across a project — without leaving the app.
Line + inline character diff, syntax highlighting, ignore whitespace / case / EOL, encoding detection, in-place edit, and one-click beautify (Prettier).
diff3 engine auto-merges one-sided changes; a UI resolves conflicts (take left / base / right / both) and saves.
Two-pane aligned lists, parallel scan + blake3 hashing, filters, progress & cancel, double-click to open a file diff.
Mirror / update / two-way with a dry-run preview before apply; copy & delete preserving timestamps.
Auto-detect delimiter & header, align rows, highlight changed cells.
Byte-level compare with offset + hex + ASCII, differing bytes highlighted.
Side-by-side, slider wipe, and pixel-difference map with a change percentage.
Diff Windows .reg exports; browse & compare zip / tar / tar.gz like folders.
Compare working ↔ HEAD, staged, or any two branches / commits / tags / stashes — then open a file's text diff. Runs on the git CLI.
Headless compare / sync with CI-friendly exit codes and HTML/CSV report export.
Export a folder comparison to a self-contained HTML page or a CSV for review.
Every comparison is remembered; reopen it in one click. Save a whole multi-tab session as a workspace and restore it later.
Light / dark, six accent colors, four fonts and adjustable text size — plus a full-window background image (local file or Google Drive link) with opacity & blur.
Claude, OpenAI or Gemini: explain a diff, summarize a changeset, review, or suggest a merge — you bring the key.
Local-first, keys in the OS keychain, optional redaction before anything is sent to an AI provider.
A peek at a few of the built-in tools — no extra apps, no context switching.
name is interpolated safely. Behavior is identical for normal input;
no functional risk. Cosmetic + minor readability improvement.
Pull the current comparison into context with one click, then ask for an explanation, a summary, a review, or a merge suggestion. Bring your own key (Anthropic, OpenAI, Gemini) — stored in your OS keychain, never in the UI.
The same engine that powers the UI runs headless. Fail a build when a generated folder drifts, produce an HTML/CSV diff report as a build artifact, or script a folder sync.
No account, no telemetry, no cloud lock-in. Everything runs on your machine.
AI provider keys live in the OS keychain and are read only inside the Rust core — there is no command that returns a key to the UI.
Optional (on by default) redaction masks API keys, tokens, private keys, emails and password assignments before any AI request.
Parallel scanning, blake3 hashing, and virtualized lists keep huge folders responsive — all offline.
Free and open-source (MIT). Download an installer for your OS, or clone the repo and run from source.