FixThatAppAll Tools
Writing

Text Diff Checker

Compare two text blocks and highlight differences.

How This Tool Works

The Text Diff Checker compares two text blocks and highlights the differences — additions, deletions, and changes. It uses the Myers diff algorithm, which finds the minimum edit distance between two texts. Output is shown in a side-by-side or unified diff format. Common uses: comparing versions of a document or contract, spotting the difference between two API responses, checking what changed between two configuration files, comparing original and edited translation text, and reviewing code changes without a full git diff setup.

How to Use

  1. Paste the original text in field A.
  2. Paste the modified text in field B.
  3. Click Run. Added content is highlighted in green; removed content in red.
  4. For large files: the diff focuses on changed sections. Unchanged sections are collapsed.

Common Questions

What does a unified diff look like?

Lines starting with + are additions (in B but not A). Lines starting with − are deletions (in A but not B). Lines starting with a space are unchanged context. @@ −1,4 +1,5 @@ means the chunk starts at line 1 in the original (4 lines) and line 1 in the new (5 lines).

What is the difference between line diff and word diff?

Line diff highlights entire lines that changed. Word diff highlights only the specific words within a line that changed. Word diff is more precise for prose editing; line diff is standard for code.

Should I use this or git diff?

Use this tool when you don't have git, for non-code comparisons (contracts, documents, translations), or for a quick visual comparison. Use git diff for tracked code changes — it preserves history and integrates with your version control workflow.