How to Compare Code Files Online — Complete Diff Guide 2025
Whether you're reviewing pull requests, debugging regressions, comparing config files, or resolving merge conflicts — understanding code differences is a core developer skill. This guide covers all five diff view modes and when to use each.
The 5 Diff View Modes — When to Use Each
- Unified view: All changes in a single column with +/- prefixes. Standard git diff format. Best for patch files, GitHub issues, long diffs.
- Split view: Original left, modified right, aligned row-by-row. Best for complex changes needing visual side-by-side comparison.
- Word-level diff: Highlights individual changed words, not entire lines. Best for renamed variables, changed parameters, or updated values.
- Inline diff: Added/removed content shown inline on the same row. Best for spotting small changes quickly.
- 3-Way merge: Base + Version A + Version B simultaneously. Best for resolving merge conflicts between two branches.
💡 Pro tip: Use "Ignore whitespace" when comparing reformatted or re-indented code — it filters pure whitespace changes so you only see semantically meaningful differences. Use Word-level after identifying a changed line to see exactly which token changed.
What is a Language Converter?
The Language Converter tab uses Claude AI to translate code logic from one programming language to another — preserving functionality while adapting idioms, syntax, and standard library usage to the target language. Useful when migrating a codebase, learning how concepts map between languages, or porting algorithms.