OmniDiff 0.3.0: Rust Diff Tool That Understands Your Code

OmniDiff 0.3.0, a Rust-based git difftool replacement that diffs code by syntax tree using tree-sitter and the APTED tree-diff algorithm, was released this week with embedded language support for shell inside YAML blocks, CSS and HTML inside template literals, TSX inside JSON fields, and Tailwind/clsx class lists in JSX. Against a labeled corpus of real-world diffs, OmniDiff reports 90% of changes completely correct versus 64% for Difftastic, with a median diff time of 4.2ms and a slowest file at 803ms versus Difftastic's 2000ms+. Version 0.3.0 also adds binary file diffing for archives, fonts, PDFs and images, and ships a 22% average performance improvement with 22–43% gains on large files.

Your AI coding assistant just rewrote three functions, added a formatting pass, and touched 15 files. git diff shows 400 changed lines. None of them tell you what actually changed. OmniDiff 0.3.0 , released this week, is a Rust-based git difftool replacement that diffs code by its syntax tree rather than line count — and version 0.3.0 adds the feature developers have been asking for: embedded language support. How It Works OmniDiff parses both versions of a file with tree-sitter https://tree-sitter.github.io/tree-sitter/ 25 languages supported and runs the APTED tree-diff algorithm on the resulting ASTs. The result: a reformatted function shows as “moved,” not deleted and re-added. A variable rename shows as an update, not 40 changed lines. When a file has an unknown extension, OmniDiff falls back to plain line diffs — so it never breaks your workflow. The accuracy difference versus legacy tools is not marginal. Against a labeled corpus of real-world diffs, OmniDiff gets 90% of changes completely correct. Difftastic https://difftastic.wilfred.me.uk/ , the previous best-in-class structural diff tool, lands at 64% on the same benchmark. OmniDiff is also faster at worst-case: its slowest file clocks 803ms vs Difftastic’s 2000ms+. Median diff time is 4.2ms. What’s New in 0.3.0: Embedded Language Diffing The 0.3.0 release ships one major new capability: OmniDiff now detects when code of a different language is embedded inside a string and diffs each layer separately. Concretely: - Shell inside YAML run: and script: blocks GitHub Actions, GitLab CI, Ansible is diffed as shell - CSS and HTML inside template literals styled-components, css ... , html ... are diffed as CSS/HTML - TSX inside JSON "content" fields is diffed as TSX - Tailwind/clsx class lists in JSX className , cn , cva , twMerge — diffed class by class, not as a changed string blob If you work with GitHub Actions, Ansible playbooks, or any styled-components codebase, this is a direct quality-of-life upgrade. Version 0.3.0 also ships a 22% performance improvement on average and 22–43% improvement on large files. Binary Files, Finally Standard git diff on a binary file prints “Binary files differ” and stops. OmniDiff does not. It diffs: - Archives zip, jar, tar, gz, xz, bz2 — member by member, with Java .class files decompiled to listings - Fonts TTF, OTF, WOFF, WOFF2, EOT — glyph by glyph - PDFs — page by page, with changed region descriptions - Images — pixel-aware diff with a change description Design tokens, bundled fonts, exported PDFs — these live in git repositories. Knowing what actually changed in a font file or a bundled archive matters, and OmniDiff is currently the only git difftool that provides it. Installing and Configuring OmniDiff installs from crates.io: cargo install --locked omnidiff Then run the interactive setup wizard, which asks whether to configure globally or for the current repo only: omnidiff git configure To use OmniDiff with git diff and git log -p not just git difftool : GIT EXTERNAL DIFF=omnidiff git diff GIT EXTERNAL DIFF=omnidiff git log -p A VS Code plugin https://marketplace.visualstudio.com/items?itemName=ivankovic.omnidiff is also available for in-editor diffs. Who Should Switch If you are reviewing pull requests that contain AI-generated code, the answer is: everyone. AI coding assistants produce reformats, moves, and rewrites that trip line-based diffs into showing false positives. OmniDiff’s structural approach cuts that noise. It is also the right tool for repos with binary assets — font files, bundled JARs, exported PDFs — where “Binary files differ” tells you nothing. The project is open source on GitHub https://github.com/ivankovic/omnidiff under AGPLv3, with a showcase at ivankovic.github.io/omnidiff/showcase https://ivankovic.github.io/omnidiff/showcase/ . The Hacker News thread https://news.ycombinator.com/item?id=50325253 from the Show HN post has 316 points and is worth reading for edge cases and comparisons.