Online Diff Checker

No. Everything runs locally in your browser using standard web APIs — your text, files and inputs are never uploaded to a server, so the tool works even offline once the page has loaded.

Yes — it works on any plain text, including source code, JSON, YAML, logs and prose. It compares line by line and marks each difference, with added lines highlighted in green, removed lines in red, and modified lines shown side-by-side. This makes it ideal for code reviews before committing to version control, reviewing configuration changes in production environments, or auditing changes to deployment scripts. The line-by-line granularity catches all structural changes while remaining readable for both code and human-readable formats.

It highlights changes at the line level, which is the clearest view for most reviews. Lines that differ are marked as added or removed, making it easy to spot which entire lines were added, deleted, or modified between the two versions. While word-level diffs can sometimes obscure the overall structure of changes, line-level comparison gives you the context you need to understand the scope of modifications. For text and code reviews, line-level comparison is typically the best balance between detail and readability, especially when tracking changes across multiple sections of a file.