diffs.nvim

Syntax highlighting for diffs in Neovim

Enhance vim-fugitive and Neovim's built-in diff mode with language-aware syntax highlighting.

Features

• Treesitter syntax highlighting in fugitive diffs and commit views
• Character-level intra-line diff highlighting (with optional vscode-diff FFI backend for word-level accuracy)
• :Gdiff unified diff against any revision
• Background-only diff colors for &diff buffers
• Inline merge conflict detection, highlighting, and resolution
• Vim syntax fallback, configurable blend/priorities

Requirements

• Neovim 0.9.0+

Installation

Install with your package manager of choice or via luarocks:

luarocks install diffs.nvim

Documentation

:help diffs.nvim

Known Limitations

• Incomplete syntax context: Treesitter parses each diff hunk in isolation. Context lines within the hunk provide syntactic context for the parser. In rare cases, hunks that start or end mid-expression may produce imperfect highlights due to treesitter error recovery.

• Syntax "flashing": diffs.nvim hooks into the FileType fugitive event triggered by vim-fugitive, at which point the buffer is preliminarily painted. The decoration provider applies highlights on the next redraw cycle, causing a brief visual "flash".

• Cold Start: Treesitter grammar loading (~10ms) and query compilation (~4ms) are one-time costs per language per Neovim session. Each language pays this cost on first encounter, which may cause a brief stutter when a diff containing a new language first enters the viewport.

• Vim syntax fallback is deferred: The vim syntax fallback (for languages without a treesitter parser) cannot run inside the decoration provider's redraw cycle due to Neovim's restriction on buffer mutations. Vim syntax highlights for these hunks appear slightly delayed.

• Conflicting diff plugins: diffs.nvim may not interact well with other plugins that modify diff highlighting. Known plugins that may conflict:

  • diffview.nvim - provides its own diff highlighting and conflict resolution UI
  • mini.diff - visualizes buffer differences with its own highlighting system
  • gitsigns.nvim - generally compatible, but both plugins modifying line highlights may produce unexpected results
  • git-conflict.nvim - diffs.nvim now includes built-in conflict resolution; disable one or the other to avoid overlap

Acknowledgements

• vim-fugitive
• @esmuellert / codediff.nvim - vscode-diff algorithm FFI backend for word-level intra-line accuracy
• diffview.nvim
• difftastic
• mini.diff
• gitsigns.nvim
• git-conflict.nvim
• @phanen - diff header highlighting, unknown filetype fix, shebang/modeline detection, treesitter injection support, decoration provider highlighting architecture